Inadequate rice production worldwide is largely attributed to abiotic and biotic stresses, along with high sensitivity of
cultivable plant germplasm. In the field of cereal biotechnology, rice engineering plays an important role in achieving tol
erance to such stresses. Plant transformation and selection play crucial role in rice engineering. This review summarized
the antibiotic, herbicide and metabolic selection marker genes (SMG) employed in diverse rice engineering studies. These
SMGs are no longer required after the transformation has been achieved, hence undesirable at the commercial level. This
study also included several strategies employed in rice engineering to eliminate such foreign DNA elements. These include
co-transformation, site-specific recombination, transposon and CRISPR base approaches. CRISPR/Cas9 being simple and
efficient, is considered a crucial step toward clean gene technology. Further ease and applicability of CRISPR/Cas9 in the
embryos directly can help us to modify target genes with efficient marker-free selection in minimum time. Overall, this review
summarizes and analyse the recent advances that have enormous potential in rice improvement.
Transgenic plants are plants that have had their genomes modified through genetic engineering by adding or removing genes. Genetic engineering can make plants resistant to diseases, insects, herbicides, or environmental stresses. Some applications of transgenic plants include producing insect-resistant crops using Bt genes, virus-resistant crops, increasing crop yields, improving nutrition by adding essential amino acids, and using plants to produce industrial compounds. Commercially grown transgenic crops include herbicide-resistant soybeans and insect-resistant corn and cotton.
Applications Of Biotechnology For Crop Improvement Prospects And ConstraintsAngela Shin
This document reviews the prospects and constraints of applying biotechnology for crop improvement. It discusses how biotechnology, including genetic engineering and genomics, can help meet increasing global food demand by developing crops with improved traits like disease resistance, drought tolerance, and nutritional quality. While biotechnology has great potential, ensuring biosafety and gaining public acceptance of genetically modified crops remain challenges. The review outlines various biotechnology applications for major crops and how techniques like genetic transformation and marker-assisted breeding can more rapidly introduce novel genes into elite varieties compared to conventional breeding. Overall, biotechnology is poised to play an important role in sustaining food production if its benefits are clearly communicated and technologies are responsibly developed and regulated.
Biotechnology improvement tools in sugarcane crop improvement vishwas chaudhari
Sugarcane is one of the most important cash crops grown in tropical and subtropical regions. It is cultivated widely in India and other parts of the world. The document discusses the importance of sugarcane as a cash crop and its production in India. It also summarizes the use of biotechnological tools like tissue culture and genetic transformation that can help address challenges in sugarcane production like abiotic and biotic stresses and develop improved varieties.
Transgenic crops are genetically modified crops containing genes artificially inserted from another species. The first GM crop was a tobacco plant in 1982, and the first approved for sale in the US was the FlavrSavr tomato in 1994. GM crops are developed using genetic engineering techniques to speed up traditional breeding and introduce a wider variety of genes. Potential benefits include increased yields, insect and disease resistance, and improved nutrition. However, there are also concerns about the impacts on human and environmental health.
Rice is one of the most important cereal crops, providing a staple food for nearly half of the global population. It is predominantly grown and consumed in Asia, where over 55% of the world's population lives. Rice production and consumption are expected to increase in the coming decades to support rising global population. Current rice research focuses on developing new varieties through biotechnology to improve yield, enhance nutritional value, and increase tolerance to environmental stresses like drought, salinity, and diseases. Transgenic techniques like Agrobacterium-mediated transformation allow introduction of novel genes into rice to generate stress-resistant and nutritionally fortified varieties.
Genetically Modified Crops – A Potential Risk for Sustainable Agriculture.PDFGordana Zdjelar
This document discusses genetically modified crops and their potential risks and impact on sustainable agriculture. It notes that GM crops were developed to expedite crop improvement for food quality and solve problems in commercial agriculture like disease and weed management. However, their introduction has raised debates about environmental and food safety issues. The most common GM crop is herbicide-tolerant soybean, which occupies 50% of the global biotech area. A major problem is the outbreak of glyphosate-resistant weeds caused by overuse of herbicides on GM soybean crops.
Any nutritious substance that people or animals eat or drink or those plants absorb in order to maintain life and growth is called Food. With the huge increasing population of the world, food production from natural resources could not meet their needs. So researchers move to produce more food using molecular-level techniques. This type of food is called genetically modified food (GM food), whose genetic material has been altered which is not present already in nature. GM food is made to increase nutrient content by alternation, has many advantages for humans as it increases the nutritional content and formation of pest, drought, herbicide, and cold resistant plants. But at the same time, it has negative impacts also. It is genetically unsafe, causing organ damage and allergic reactions in the digestive tract. The researchers are trying to do their best to produce crops with their desired characteristics by using molecular-level techniques.
Transgenic plants are plants that have had their genomes modified through genetic engineering by adding or removing genes. Genetic engineering can make plants resistant to diseases, insects, herbicides, or environmental stresses. Some applications of transgenic plants include producing insect-resistant crops using Bt genes, virus-resistant crops, increasing crop yields, improving nutrition by adding essential amino acids, and using plants to produce industrial compounds. Commercially grown transgenic crops include herbicide-resistant soybeans and insect-resistant corn and cotton.
Applications Of Biotechnology For Crop Improvement Prospects And ConstraintsAngela Shin
This document reviews the prospects and constraints of applying biotechnology for crop improvement. It discusses how biotechnology, including genetic engineering and genomics, can help meet increasing global food demand by developing crops with improved traits like disease resistance, drought tolerance, and nutritional quality. While biotechnology has great potential, ensuring biosafety and gaining public acceptance of genetically modified crops remain challenges. The review outlines various biotechnology applications for major crops and how techniques like genetic transformation and marker-assisted breeding can more rapidly introduce novel genes into elite varieties compared to conventional breeding. Overall, biotechnology is poised to play an important role in sustaining food production if its benefits are clearly communicated and technologies are responsibly developed and regulated.
Biotechnology improvement tools in sugarcane crop improvement vishwas chaudhari
Sugarcane is one of the most important cash crops grown in tropical and subtropical regions. It is cultivated widely in India and other parts of the world. The document discusses the importance of sugarcane as a cash crop and its production in India. It also summarizes the use of biotechnological tools like tissue culture and genetic transformation that can help address challenges in sugarcane production like abiotic and biotic stresses and develop improved varieties.
Transgenic crops are genetically modified crops containing genes artificially inserted from another species. The first GM crop was a tobacco plant in 1982, and the first approved for sale in the US was the FlavrSavr tomato in 1994. GM crops are developed using genetic engineering techniques to speed up traditional breeding and introduce a wider variety of genes. Potential benefits include increased yields, insect and disease resistance, and improved nutrition. However, there are also concerns about the impacts on human and environmental health.
Rice is one of the most important cereal crops, providing a staple food for nearly half of the global population. It is predominantly grown and consumed in Asia, where over 55% of the world's population lives. Rice production and consumption are expected to increase in the coming decades to support rising global population. Current rice research focuses on developing new varieties through biotechnology to improve yield, enhance nutritional value, and increase tolerance to environmental stresses like drought, salinity, and diseases. Transgenic techniques like Agrobacterium-mediated transformation allow introduction of novel genes into rice to generate stress-resistant and nutritionally fortified varieties.
Genetically Modified Crops – A Potential Risk for Sustainable Agriculture.PDFGordana Zdjelar
This document discusses genetically modified crops and their potential risks and impact on sustainable agriculture. It notes that GM crops were developed to expedite crop improvement for food quality and solve problems in commercial agriculture like disease and weed management. However, their introduction has raised debates about environmental and food safety issues. The most common GM crop is herbicide-tolerant soybean, which occupies 50% of the global biotech area. A major problem is the outbreak of glyphosate-resistant weeds caused by overuse of herbicides on GM soybean crops.
Any nutritious substance that people or animals eat or drink or those plants absorb in order to maintain life and growth is called Food. With the huge increasing population of the world, food production from natural resources could not meet their needs. So researchers move to produce more food using molecular-level techniques. This type of food is called genetically modified food (GM food), whose genetic material has been altered which is not present already in nature. GM food is made to increase nutrient content by alternation, has many advantages for humans as it increases the nutritional content and formation of pest, drought, herbicide, and cold resistant plants. But at the same time, it has negative impacts also. It is genetically unsafe, causing organ damage and allergic reactions in the digestive tract. The researchers are trying to do their best to produce crops with their desired characteristics by using molecular-level techniques.
Any nutritious substance that people or animals eat or drink or those plants absorb in order to maintain life and growth is called Food. With the huge increasing population of the world, food production from natural resources could not meet their needs. So researchers move to produce more food using molecular-level techniques. This type of food is called genetically modified food (GM food), whose genetic material has been altered which is not present already in nature. GM food is made to increase nutrient content by alternation, has many advantages for humans as it increases the nutritional content and formation of pest, drought, herbicide, and cold resistant plants. But at the same time, it has negative impacts also. It is genetically unsafe, causing organ damage and allergic reactions in the digestive tract. The researchers are trying to do their best to produce crops with their desired characteristics by using molecular-level techniques.
The document discusses the history and applications of agricultural biotechnology. It begins with the early domestication of crops by farmers selecting desirable traits over thousands of years. More recently, biotechnology has been used to develop crops with increased yields, disease resistance, and nutritional value. Examples discussed include Golden Rice, which was engineered to produce beta-carotene to address vitamin A deficiency, and the development of pesticide-resistant crops and plants that can serve as vaccines when ingested. The document also examines the use of biotechnology to improve animal health, create antibiotics, and enhance the traits of ornamental plants and flowers.
This document discusses GMO foods in Bangladesh. It provides background on genetic modification and lists some common GMO foods like soybeans, corn, and cotton. The top GMO crop producing countries are identified as the US, Brazil, Argentina, India, and Canada. The document also outlines both the advantages and disadvantages of GMO foods. The advantages include increased crop yields and reduced use of pesticides, while disadvantages include potential effects on other organisms and insects developing resistance. Overall, the conclusion is that GMO foods are generally considered safe but public understanding needs to be improved.
This document discusses genetically modified crops and their potential impact. It begins by introducing how GM crops could help address the problem of chronic hunger by increasing yields and environmental stress resistance. It then provides definitions of GM crops, examples of GM crops grown in India including Bt cotton, corn, and golden rice. It discusses the history and development of GM crops. It also outlines some objectives and benefits of GM crops, as well as potential problems associated with them including health and environmental risks. Finally it discusses future applications of GM crop technology.
A Review on Future Challenges in the field of Plant BiotechnologyIRJET Journal
This document provides an overview of plant biotechnology and its future challenges. It discusses how plant biotechnology has increased food production through domestication and genetic engineering. However, further improvements are still needed to meet growing global demands. Key future challenges include increasing crop yields, developing pest and disease resistance, and producing biomaterials and biofuels without competing with food supplies. Advances in genomics, molecular techniques, and multidisciplinary approaches will be required to address these challenges and realize the full potential of plant biotechnology.
Plant breeding potential and opportunities .pptxAgnivesh Yadav
The document discusses plant breeding, including its goals, methods, opportunities and recent research areas. Plant breeding aims to genetically improve plants for traits like higher yield, improved quality, biotic and abiotic resistance, and wider adaptability. Recent areas of focus include biofortification to increase nutrient levels, developing resistance to diseases and insects, and exploiting heterosis. Future opportunities lie in improving water and nutrient use efficiency, weed competitiveness and storage duration. Advances in breeding will be crucial to address global challenges to food security under changing environmental conditions.
Global developments of genome editing in agricultureOECD Environment
This presentation covers the scope of agricultural applications of genome editing by describing the relevance of these techniques to agriculture especially crop plants, farm animals as well as the foods and feeds derived from them.
transgenic for crop improvement , global scenario and prospects anubhav aryal
Transgenic crops have been developed since the 1980s to introduce desirable traits like pest or disease resistance. The first commercially grown transgenic crops in the 1990s were FlavrSavr tomatoes and herbicide-resistant soybeans. Global transgenic crop area has grown significantly, reaching 160 million hectares in 2011 led by the US, Brazil, India, and Argentina. Transgenic crops can help address issues of rising population and food insecurity by increasing yields, but also raise some risks to human and environmental health that require assessment and management of biosafety issues.
Application of Mutation Breeding Techniques for Crop Variety Development Mahbubul Hassan
This document provides an overview of mutation breeding techniques for developing new crop varieties. It discusses the need to develop varieties that can tolerate drought, salinity, and other stresses due to increasing population and decreasing arable land. Mutation breeding is described as a proven method for creating genetic variations within a crop species. The key steps in a mutation breeding program are outlined, including selecting a variety for mutagen treatment, determining the optimal mutagen dose, treating plant parts with the mutagen, and selecting desirable mutants in subsequent generations through yield trials. The document highlights that over 3,200 mutant varieties have been released worldwide using techniques like gamma irradiation. It also reviews characteristics evaluated during mutant selection for traits such as yield, drought tolerance, and disease
PRESENT STATUS AND ROLE OF BIOTECHNOLOGICAL APPROACHES IN INSECT PEST MANAGEMENTNAGANNA REPALLE
This document provides an overview of biotechnological approaches for insect pest management. It discusses how transgenic plants expressing insecticidal genes like Bt toxins have helped reduce crop losses from pests. Other techniques described include using RNA interference to silence pest genes, molecular markers to identify pest populations, and newer proteins being explored for transgenic crops. The document also outlines India's regulatory system for genetically modified crops and both the benefits and concerns associated with their use.
Breeding for Development of Climate Resilient Chickpea.pptxKanshouwaModunshim
The breeding for the development of Climate Resilient Chickpea is a critical initiative aimed at enhancing the productivity and adaptability of chickpea genotypes under challenging environmental conditions. Chickpea, a vital pulse crop globally, faces yield limitations due to the combined impact of heat, cold, drought, and salinity stresses. The average yields, currently far below the potential, necessitate the development of highly productive and resilient chickpea cultivars. Traditional breeding methods and modern genomic resources, including molecular markers, genetic maps, and QTL identification, have been instrumental in enhancing grain yields and stress adaptation. Marker-assisted backcrossing has successfully produced cultivars like Pusa Manav, demonstrating the effectiveness of genomic technologies. Additionally, the adoption of gene-editing technologies, such as CRISPR-Cas9, holds promise in accelerating genetic gain for stress-related traits.
Solutions for Impact in Emerging Markets: The role of biotechnologyICRISAT
To develop and deploy state-of-the-art infrastructure for conduct of transgenic research and to act as a clearinghouse for technology inputs, transgenic research leads/ prototypes with proof of concept derived from Indian research institutes, universities, and other likely sources.Also to evolve the technology to a point where a practical application can be demonstrated, and transfer this “evolved” technology for product development and distribution to appropriate agencies.
Breeding rice for sustainable agricultureDhanuja Kumar
Rice is the major cereal crop in Asia where 90% of the world’s rice is produced and consumed. Rice production and productivity need to keep pace with a growing global population likely to reach 9 billion by 2050 in order to have a hunger-free world and to ensure sustainable production in the face of depleting resources such as land, water and nutrients as well as changing climatic conditions.
Different breeding techniques for development of varities and hybrids that are allowed according to IFOAM Norms and need for development of varities specific for organic conditions. Importance of organic foods in current situation in context with health befits and environmental safety as well. To prevent health and environmental side effects form harmful chemicals.
Breeding for yield potential and stress adaptation in riceAshish Tiwari
With resources such as land being limited, increasing yield potential holds an important place for feeding the growing population. Stress is one of the main reasons for hindering the full flourish potential of any crop. Thus, breeding for increasing yield potential as well as stress adaptability goes hand in hand. Various conventional as well as advanced breeding methods along with the understanding of crop physiology can help us achieve the goal
Application of molecular biology to conventional disease strategies ( M.Phil ...Satya Prakash Chaurasia
As resistance to disease in plants is genetically controlled, molecular tools like breeding resistant cultivars has been an intensively used approach for crop protection since near beginning of human civilization, the time when we did not know its molecular aspects. Even today, molecular biology is applied in multiple ways to control plant diseases. Some of which are breeding, tissue culture, marker assisted breeding, QTL- mapping, identification of novel resistance genes etc. With the commencement of advanced technologies in the recent past, we are now able to genetically modify a plant without wasting a lot of time and avoiding problems of sexual incompatibility which we encounter in breeding programs.
Nagaraju r&d annual meeting 2019 to 2020NagarajMadala
Pre-Breeding helps to develop new genetic resources using genomic tools to predict the effect of introducing different genes from wild relatives into cultivated varieties.
Genetic Diversity Studies in Rice for Bacterial Leaf Blight Resistanceijtsrd
Bacterial blight (BLB), caused by Xanthomonas oryzae PV. oryzae (Xoo) is one of the most destructive diseases active in the major rice growing countries of Asia. In field level screening, the genotypes PY5 and Kadaikannan showed immune against rice BLB. Under artificial condition, IR 11C 114, Adukan and Kadaikannan shows resistant to bacterial leaf blight. The trait single plant yield showed positive significant correlation with plant height (0.21), number of productive tillers (0.19) and thousand grain weight (0.37). G. Tamilarasan | M. Arumugam Pillai | R. Kannan | S. Merina Prem Kumari"Genetic Diversity Studies in Rice for Bacterial Leaf Blight Resistance" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd15915.pdf http://www.ijtsrd.com/biological-science/pathology/15915/genetic-diversity-studies-in-rice-for-bacterial-leaf-blight-resistance/g--tamilarasan
Somaclonal Variation: A new dimension for sugarcane improvementDr. siddhant
Plant tissue culture or micropropagation technique is the rapid method to multiply newly released cultivar in limited
time. Crop improvement by conventional method in vegetatively propagated crops like sugarcane is very difficult due to
its narrow genetic base and other limitations. Somaclonal variations are easily achieved in asexually propagated crops
like sugarcane and banana. Tissue culture derived variations are known as somaclonal variation. These variations play
an important role in crop improvement program. Genetic variations are heritable in next generation and important for
crop improvement, epigenetic changes are temporary ultimately reversible. Mutation breeding is also very advantageous
for improving a cultivar. Somaclonal variants of sugarcane are available for several traits like drought, salt tolerance, red
rot, eye spot disease, quality and quantity trait. Molecular marker techniques like RFLP, RAPD, AFLP and SSR etc. are
regularly used preferentially over traditional phenotypic or cytological methods.
1. The document discusses transgenic or genetically modified crops. Transgenic crops are defined as plants containing genes artificially introduced from other organisms.
2. The history of transgenic crop development is reviewed, noting the first transgenic tobacco in 1983, and first commercial crops like Bt cotton in 2002. Methods of genetic engineering allow direct transfer of one or few genes between closely or distantly related species.
3. GM crops can help address climate change by reducing fuel use and soil erosion from practices like no-till farming. However, there are also risks to consider from unintended effects of gene transfer and development of pest resistance.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
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Similar to Selectable Markers to Marker‑Free Selection in Rice
Any nutritious substance that people or animals eat or drink or those plants absorb in order to maintain life and growth is called Food. With the huge increasing population of the world, food production from natural resources could not meet their needs. So researchers move to produce more food using molecular-level techniques. This type of food is called genetically modified food (GM food), whose genetic material has been altered which is not present already in nature. GM food is made to increase nutrient content by alternation, has many advantages for humans as it increases the nutritional content and formation of pest, drought, herbicide, and cold resistant plants. But at the same time, it has negative impacts also. It is genetically unsafe, causing organ damage and allergic reactions in the digestive tract. The researchers are trying to do their best to produce crops with their desired characteristics by using molecular-level techniques.
The document discusses the history and applications of agricultural biotechnology. It begins with the early domestication of crops by farmers selecting desirable traits over thousands of years. More recently, biotechnology has been used to develop crops with increased yields, disease resistance, and nutritional value. Examples discussed include Golden Rice, which was engineered to produce beta-carotene to address vitamin A deficiency, and the development of pesticide-resistant crops and plants that can serve as vaccines when ingested. The document also examines the use of biotechnology to improve animal health, create antibiotics, and enhance the traits of ornamental plants and flowers.
This document discusses GMO foods in Bangladesh. It provides background on genetic modification and lists some common GMO foods like soybeans, corn, and cotton. The top GMO crop producing countries are identified as the US, Brazil, Argentina, India, and Canada. The document also outlines both the advantages and disadvantages of GMO foods. The advantages include increased crop yields and reduced use of pesticides, while disadvantages include potential effects on other organisms and insects developing resistance. Overall, the conclusion is that GMO foods are generally considered safe but public understanding needs to be improved.
This document discusses genetically modified crops and their potential impact. It begins by introducing how GM crops could help address the problem of chronic hunger by increasing yields and environmental stress resistance. It then provides definitions of GM crops, examples of GM crops grown in India including Bt cotton, corn, and golden rice. It discusses the history and development of GM crops. It also outlines some objectives and benefits of GM crops, as well as potential problems associated with them including health and environmental risks. Finally it discusses future applications of GM crop technology.
A Review on Future Challenges in the field of Plant BiotechnologyIRJET Journal
This document provides an overview of plant biotechnology and its future challenges. It discusses how plant biotechnology has increased food production through domestication and genetic engineering. However, further improvements are still needed to meet growing global demands. Key future challenges include increasing crop yields, developing pest and disease resistance, and producing biomaterials and biofuels without competing with food supplies. Advances in genomics, molecular techniques, and multidisciplinary approaches will be required to address these challenges and realize the full potential of plant biotechnology.
Plant breeding potential and opportunities .pptxAgnivesh Yadav
The document discusses plant breeding, including its goals, methods, opportunities and recent research areas. Plant breeding aims to genetically improve plants for traits like higher yield, improved quality, biotic and abiotic resistance, and wider adaptability. Recent areas of focus include biofortification to increase nutrient levels, developing resistance to diseases and insects, and exploiting heterosis. Future opportunities lie in improving water and nutrient use efficiency, weed competitiveness and storage duration. Advances in breeding will be crucial to address global challenges to food security under changing environmental conditions.
Global developments of genome editing in agricultureOECD Environment
This presentation covers the scope of agricultural applications of genome editing by describing the relevance of these techniques to agriculture especially crop plants, farm animals as well as the foods and feeds derived from them.
transgenic for crop improvement , global scenario and prospects anubhav aryal
Transgenic crops have been developed since the 1980s to introduce desirable traits like pest or disease resistance. The first commercially grown transgenic crops in the 1990s were FlavrSavr tomatoes and herbicide-resistant soybeans. Global transgenic crop area has grown significantly, reaching 160 million hectares in 2011 led by the US, Brazil, India, and Argentina. Transgenic crops can help address issues of rising population and food insecurity by increasing yields, but also raise some risks to human and environmental health that require assessment and management of biosafety issues.
Application of Mutation Breeding Techniques for Crop Variety Development Mahbubul Hassan
This document provides an overview of mutation breeding techniques for developing new crop varieties. It discusses the need to develop varieties that can tolerate drought, salinity, and other stresses due to increasing population and decreasing arable land. Mutation breeding is described as a proven method for creating genetic variations within a crop species. The key steps in a mutation breeding program are outlined, including selecting a variety for mutagen treatment, determining the optimal mutagen dose, treating plant parts with the mutagen, and selecting desirable mutants in subsequent generations through yield trials. The document highlights that over 3,200 mutant varieties have been released worldwide using techniques like gamma irradiation. It also reviews characteristics evaluated during mutant selection for traits such as yield, drought tolerance, and disease
PRESENT STATUS AND ROLE OF BIOTECHNOLOGICAL APPROACHES IN INSECT PEST MANAGEMENTNAGANNA REPALLE
This document provides an overview of biotechnological approaches for insect pest management. It discusses how transgenic plants expressing insecticidal genes like Bt toxins have helped reduce crop losses from pests. Other techniques described include using RNA interference to silence pest genes, molecular markers to identify pest populations, and newer proteins being explored for transgenic crops. The document also outlines India's regulatory system for genetically modified crops and both the benefits and concerns associated with their use.
Breeding for Development of Climate Resilient Chickpea.pptxKanshouwaModunshim
The breeding for the development of Climate Resilient Chickpea is a critical initiative aimed at enhancing the productivity and adaptability of chickpea genotypes under challenging environmental conditions. Chickpea, a vital pulse crop globally, faces yield limitations due to the combined impact of heat, cold, drought, and salinity stresses. The average yields, currently far below the potential, necessitate the development of highly productive and resilient chickpea cultivars. Traditional breeding methods and modern genomic resources, including molecular markers, genetic maps, and QTL identification, have been instrumental in enhancing grain yields and stress adaptation. Marker-assisted backcrossing has successfully produced cultivars like Pusa Manav, demonstrating the effectiveness of genomic technologies. Additionally, the adoption of gene-editing technologies, such as CRISPR-Cas9, holds promise in accelerating genetic gain for stress-related traits.
Solutions for Impact in Emerging Markets: The role of biotechnologyICRISAT
To develop and deploy state-of-the-art infrastructure for conduct of transgenic research and to act as a clearinghouse for technology inputs, transgenic research leads/ prototypes with proof of concept derived from Indian research institutes, universities, and other likely sources.Also to evolve the technology to a point where a practical application can be demonstrated, and transfer this “evolved” technology for product development and distribution to appropriate agencies.
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Rice is the major cereal crop in Asia where 90% of the world’s rice is produced and consumed. Rice production and productivity need to keep pace with a growing global population likely to reach 9 billion by 2050 in order to have a hunger-free world and to ensure sustainable production in the face of depleting resources such as land, water and nutrients as well as changing climatic conditions.
Different breeding techniques for development of varities and hybrids that are allowed according to IFOAM Norms and need for development of varities specific for organic conditions. Importance of organic foods in current situation in context with health befits and environmental safety as well. To prevent health and environmental side effects form harmful chemicals.
Breeding for yield potential and stress adaptation in riceAshish Tiwari
With resources such as land being limited, increasing yield potential holds an important place for feeding the growing population. Stress is one of the main reasons for hindering the full flourish potential of any crop. Thus, breeding for increasing yield potential as well as stress adaptability goes hand in hand. Various conventional as well as advanced breeding methods along with the understanding of crop physiology can help us achieve the goal
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As resistance to disease in plants is genetically controlled, molecular tools like breeding resistant cultivars has been an intensively used approach for crop protection since near beginning of human civilization, the time when we did not know its molecular aspects. Even today, molecular biology is applied in multiple ways to control plant diseases. Some of which are breeding, tissue culture, marker assisted breeding, QTL- mapping, identification of novel resistance genes etc. With the commencement of advanced technologies in the recent past, we are now able to genetically modify a plant without wasting a lot of time and avoiding problems of sexual incompatibility which we encounter in breeding programs.
Nagaraju r&d annual meeting 2019 to 2020NagarajMadala
Pre-Breeding helps to develop new genetic resources using genomic tools to predict the effect of introducing different genes from wild relatives into cultivated varieties.
Genetic Diversity Studies in Rice for Bacterial Leaf Blight Resistanceijtsrd
Bacterial blight (BLB), caused by Xanthomonas oryzae PV. oryzae (Xoo) is one of the most destructive diseases active in the major rice growing countries of Asia. In field level screening, the genotypes PY5 and Kadaikannan showed immune against rice BLB. Under artificial condition, IR 11C 114, Adukan and Kadaikannan shows resistant to bacterial leaf blight. The trait single plant yield showed positive significant correlation with plant height (0.21), number of productive tillers (0.19) and thousand grain weight (0.37). G. Tamilarasan | M. Arumugam Pillai | R. Kannan | S. Merina Prem Kumari"Genetic Diversity Studies in Rice for Bacterial Leaf Blight Resistance" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd15915.pdf http://www.ijtsrd.com/biological-science/pathology/15915/genetic-diversity-studies-in-rice-for-bacterial-leaf-blight-resistance/g--tamilarasan
Somaclonal Variation: A new dimension for sugarcane improvementDr. siddhant
Plant tissue culture or micropropagation technique is the rapid method to multiply newly released cultivar in limited
time. Crop improvement by conventional method in vegetatively propagated crops like sugarcane is very difficult due to
its narrow genetic base and other limitations. Somaclonal variations are easily achieved in asexually propagated crops
like sugarcane and banana. Tissue culture derived variations are known as somaclonal variation. These variations play
an important role in crop improvement program. Genetic variations are heritable in next generation and important for
crop improvement, epigenetic changes are temporary ultimately reversible. Mutation breeding is also very advantageous
for improving a cultivar. Somaclonal variants of sugarcane are available for several traits like drought, salt tolerance, red
rot, eye spot disease, quality and quantity trait. Molecular marker techniques like RFLP, RAPD, AFLP and SSR etc. are
regularly used preferentially over traditional phenotypic or cytological methods.
1. The document discusses transgenic or genetically modified crops. Transgenic crops are defined as plants containing genes artificially introduced from other organisms.
2. The history of transgenic crop development is reviewed, noting the first transgenic tobacco in 1983, and first commercial crops like Bt cotton in 2002. Methods of genetic engineering allow direct transfer of one or few genes between closely or distantly related species.
3. GM crops can help address climate change by reducing fuel use and soil erosion from practices like no-till farming. However, there are also risks to consider from unintended effects of gene transfer and development of pest resistance.
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As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
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and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
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Nucleophilic Addition of carbonyl compounds.pptxSSR02
Nucleophilic addition is the most important reaction of carbonyls. Not just aldehydes and ketones, but also carboxylic acid derivatives in general.
Carbonyls undergo addition reactions with a large range of nucleophiles.
Comparing the relative basicity of the nucleophile and the product is extremely helpful in determining how reversible the addition reaction is. Reactions with Grignards and hydrides are irreversible. Reactions with weak bases like halides and carboxylates generally don’t happen.
Electronic effects (inductive effects, electron donation) have a large impact on reactivity.
Large groups adjacent to the carbonyl will slow the rate of reaction.
Neutral nucleophiles can also add to carbonyls, although their additions are generally slower and more reversible. Acid catalysis is sometimes employed to increase the rate of addition.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
BREEDING METHODS FOR DISEASE RESISTANCE.pptxRASHMI M G
Plant breeding for disease resistance is a strategy to reduce crop losses caused by disease. Plants have an innate immune system that allows them to recognize pathogens and provide resistance. However, breeding for long-lasting resistance often involves combining multiple resistance genes
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
2. Molecular Biotechnology
1 3
paralyzed us to get sufficient food for everyone. The ultimate
vision for 2050 is to produce staple foods on the same piece
of arable land for this increased population [5, 6].
Need of Genetic Engineering in Rice Crop
In rice crop, many promising varieties have the potential to
produce 10 ton per hectare yield under controlled environ-
ment. However, local farmers under field conditions end up
harvesting half of the actual yield reasoned to various envi-
ronmental stresses [7]. Drought, salinity, submergence, cold,
high temperature, and metal toxicity are examples of biotic
(insect and pest) and abiotic (drought, salinity, submergence,
cold, high temperature, and metal toxicity) environmental
stresses. Drought stress is one of the abiotic stresses that
poses a severe threat to world rice production when water
is scarce. Drought stress alone has been estimated to reduce
worldwide rice production by 18 million tons annually. It
affects plant growth by reducing cell growth, cell elonga-
tion, and cell expansion. As a result, reactive oxygen species
build up, damaging the plant's antioxidant system. By regu-
lating stress-induced gene and protein functions, drought
stress modifies morphological, biochemical, physiological,
and molecular responses. Salt concentrations in the soil is
another crucial factor affecting rice plant development at all
stages by causing ionic or osmotic stress [8–10]. Excess of
sodium ions compete with useful ions and upset the ionic
balance. Osmotic stress can influence the plant’s ability
to absorb water from the soil. Reduction in cellular water
potential due to the increased solute concentration affects
stomatal conductance, transpiration, gaseous exchange and
rate of carbon assimilation [11, 12]. Complete submer-
gence also affects many upland rice cultivars critically. A
moderate waterlogged environment can extend leaves and
stems, resulting in excessive energy use and death of cells
[13, 14]. Low temperatures also affect rice germination,
seedling growth, leaf curving, shoot length, flowering and
tillering [15, 16]. Further, due to the limited variety of cul-
tivable rice cultivars and the labour intensive agriculture
techniques, rice cultivation is seasonal. In order to develop
varieties resistant to these stresses, it is essential to under-
stand how plants respond to these stresses. Biggest challenge
in plant biotechnology is to develop stress tolerant plants
employing genetically engineered technology. Traditional
crop improvement practices such as plant breeding have their
own limits. At present, genetic engineering is utilized to
increase the genetic pool of crop species. As a result, genes
from a variety of organisms can be introduced with new or
enhanced functions when exposed to certain biotic and abi-
otic stresses. Being quick, accurate, and stable, genetic engi-
neering is speculated as superior alternative method. How-
ever, exact selection of true transgenics with high precision
depends on rigorous selection procedures. Through the
transfer of desirable genes, this technology allows access
to an unlimited gene pool. The transformation method quiet
efficient to produce useful plants with special phenotypes
within a short period of time, rectify faults, and improve
physiological and agronomical traits [5]. DNA introduction
and selection of true transformed plant cells/tissue constitute
two most demanding steps of rice transformation [17]. Rice
plant transformation involves introducing foreign DNA seg-
ments with a selectable marker gene (SMG) into either plant
nuclear DNA or chloroplast genome [18]. Proteins encoded
by SMGs confer competitive advantage on only transformed
cells, making them more likely to be selected in presence of
a selection agent over untransformed cells.
SMGs
Antibiotic/herbicide resistance genes are initially employed
for successfully selecting transgenic model plants resistant to
various biotic and abiotic traits. Later, the same technology
has been extended to crops including rice and other cere-
als successfully [19, 20] (Table1). Transformed cells show
resistance to antibiotics when antibiotic resistance genes
from bacterial origin are expressed under plant-specific pro-
moters. Glycopeptides and aminoglycosides constitute major
classes of antibiotics employed in plant research. Hygromy-
cin, kanamycin, neomycin, gentamicin, geneticin (G418) and
paromomycin are of aminoglycoside types whereas bleomy-
cin belongs to glycopeptide family [21]. Antibiotics in the
aminoglycoside family work as protein inhibitors, halting
cell growth [22]. Kanamycin, gentamicin, geneticin and
neomycin block protein synthesis by binding 30S subunit in
ribosome whilst hygromycin occupies the ribosome binding
site in the elongation factor EF-2 [23]. Plants’ sensitivity, on
the other hand, varies greatly between species, genotypes,
and tissues [24–27].
Antibiotic Resistant Genes as SMGs
Neomycin phosphotransferase II (aphA2), expressed by
EPSPS gene, from Escherichia coli transfer phosphate
molecule to their respective hydroxyl groups and confers
resistance to kanamycin and G418. The phosphate molecule
hinders with the interactions and binding of antibiotics to
ribosomes. Same has also been employed as a selection
marker in rice as well. Kanamycin (150 mg/l) along with
cefotaxime has been used for selecting Indica rice (Oryza
sativa L.) cv. RD6 transformants [28]. Chan et al. report the
transformation of Indica rice cv. Taichung Native 1 using
nptII gene and select the transformed rice using 20 mg/l
of kanamycin [29]. Tripathi et al. attempt to increase
4. Molecular Biotechnology
1 3
transformation efficiency by using Agrobacterium medi-
ated transformation of Oryza sativa variety, Pusa Basmati-1
(IET-10364) using callus culture and select transformed cal-
lus using 50 mg/l kanamycin [30].
Hygromycin, another antibiotic, has been successfully
used to select resistant tissue with persistent transgene
inheritance in rice [31–34]. The bacterial aph (4′) encoded
aminoglycoside phosphotransferase (also known as hygro-
mycin phosphotransferase) inactivates hygromycin by phos-
phorylating its hydroxyl group [35]. Zuraida et al. employ
10–20 mg/l hygromycin to select indica rice MR 219 [36].
Hygromycin has also been used as a selection marker for rice
transformants in other research [34, 37].
Another antibiotic known as Bleomycin has also been
employed as SMG in rice studies [38]. In the presence of
Fe2+
and
O2, the interaction of bleomycin with the 4′-car-
bon-hydrogen bond of deoxyribose causes single and double
strand DNA breaks [39]. Bleomycin resistance genes, blmB
or blmA has been identified from Streptomyces verticillus.
blmB code for bleomycin acetyl transferase (301 aa) whilst
blmA encodes bleomycin binding protein (BLMA,122 aa)
respectively. BLMA inactivates bleomycin by binding it
non-covalently (both metal-free and metal bound state) with
high affinity [40–42]. Whereas, bleomycin acetyl transferase
acetylates primary amine group of β-aminoalanine moiety
in bleomycin thus rendering it inactive. The metal che-
lated complex is prevented from coordinating and reducing
molecular oxygen by acetylation. If oxygen free radicals are
not suppressed, single-stranded and double-stranded DNA
breaks occur, resulting in cell death [19, 43, 44]. Dekeyser
et al. has employed 20 mg/l concentration of bleomycin to
select rice plants transformants [38].
Herbicides Resistant Genes as SMGs
A few herbicide-tolerant genes, such as bar, pat, and aroA,
are used as SMGs to select transformed plant tissue. Phos-
phinothricin-N-acetyltransferase enzymes encoded by the
bar and pat genes of Streptomyces hygroscopicus and Strep-
tomyces viridochromogenes acetylate and detoxify phosphi-
nothricin. Although, Phosphinothricin-N-acetyltransferase
enzymes encoded by these two genes share 85% identity at
the amino acid level, they are functionally equivalent [45,
46]. Transgenic lines have already been selected using phos-
phinothricin as selection agent. At 4 and 8 mg/l glufosinate
ammonium (the ammonium salt of phosphinothricin), Cao
et al. observe substantial cell growth retardation in rice sus-
pension culture (Oryza sativa L. cv Taipei 309 [47]). Other
studies also report the selection of rice transformants using
4 mg/l of glufosinate ammonium [38, 47].
Glyphosate, a herbicide work by competitively binding to
5-enolpyruvyl shikimate 3-phosphate synthase, also called
aroA enzyme of shikimate pathway this inhibiting biosyn-
thesis of aromatic amino acids. The impaired synthesis of
aromatic amino acids and secondary metabolites thus results
in plant cell death [48, 49]. In plants, glyphosate resistance
has been achieved by introducing genes encoding an EPSPS
enzyme with reduced affinity for glyphosate. A modified
EPSPS has been employed to achieve enhanced glyphosate
resistance in transgenic rice [50, 51]. In lab experiments
and field trials, transgenic japonica rice cultivar Xiushui-110
harbouring a novel G6 gene from Pseudomonas putida
(encoding EPSPS) tolerates 8 gm/l of glyphosate concen-
tration compared to conventional rice sensitive to 1 g/l weed
control glyphosate spray dose [52]. Cui et al. develops novel
glyphosate tolerant Japonica rice lines by transforming epsps
gene from Isoptericola variabilis gene using Agrobacterium
mediated transformation method and select resistant calli
using 200 mg/l glyphosate [53].
Metabolic Genes as SMGs
Many plants, including rice, lacking phosphomannose-
isomerase, are unable to grow in the presence of mannose
and accumulate it as mannose-6-phosphate in the roots
[54]. The accumulation of mannose-6-phosphate inhibits
phosphoglucose isomerase and thus glycolysis [55]. Phos-
phomannose isomerase enzyme encoded by manA gene of
E. coli has been employed in rice crop [54, 56, 57]. manA
encoded phosphomannose isomerase catalyses the conver-
sion of mannose 6-phosphate to fructose 6-phosphate [25].
He et al. utilise 25 g/l of mannose to select Japonica rice
(Oryza sativa L. ssp. Japonica, var. Ishikari-shiroge, I-S)
transformants [54]. In another study, Zai-Song employs a
combination of 10 g/l of mannose and 5 g/l of glucose for
selecting japonica rice variety Zhonghua 8 [57].
Perspectives of Selectable Marker
to Marker‑Free Selection in Rice
SMG coupled to a transgene gives transformed cells a
growth advantage during the transformation process in gen-
eral. After achieving successful transformation, these SMGs
are no longer required, thus undesirable. Integration of SMG
in genetically modified (GM) crops is a fundamental deter-
minant of the commercialization of GM plants and their
products. It's extremely unlikely that a gene could be hori-
zontally transferred from plant products to the gut micro-
biota, intestinal cells, the environment, or therapeutically
important bacteria. In 2009, China’s Ministry of Agriculture
gave biosafety certificates to two transgenic rice cultivars,
Huahui No. 1 and Bt Shanyou 63. Both of these cultivars
are pest-resistant and carry pest-resistant transgenes. The
5. Molecular Biotechnology
1 3
hph gene, conferring resistance to hygromycin, has been
employed as a selective marker gene in both these cultivars
[58]. Furthermore, despite transgenics delivering environ-
mental benefits, the study emphasises risk management to
restrict gene flow from Bt rice to wild and weedy rice [59].
After long-term intake of GM rice, maize, and potato, an
animal study finds little differences in biochemical, haema-
tological, and histological assessment when compared to a
control group. Because the impacts are non-toxic and fall
within the typical variation range, the study concludes that
GM foods are nutritionally equivalent to their wild coun-
terparts. Wang et al. looked at the effect of the bar gene
(an anti-herbicide) in rice transgenics to see if it was safe
to eat. Rats fed with transgenic rice for 30 days, show no
change in body weight, organs, blood composition, or other
pathohistological characteristics, rendering it as safe [60].
Basmati rice is highly prized in India, although it is nutri-
tionally deficient. To boost the nutritional value of rice
basmati, transgenic studies have been proposed. However,
because our country’s rules prohibit the sale of genetically
modified foods, a premium crop like Basmati cannot be
used in a unique fashion [61]. Herbicide-resistant transgenic
rice varieties have been licenced for usage in the United
States, although they have yet to be commercialised. India
has approved limited field experiments for insect, bacterial
blight, fungus, salt, and pest-resistant transgenic rice. To
date, severe restrictions and policies control the commer-
cialization of transgenic rice and other cereal crops in many
nations. The most serious concern about eating GM food
is the spread of antibiotic-resistant genes from transgenic
plants to bacterial populations, resulting in superbugs. As
a result, scientists are concentrating their efforts on reduc-
ing genetic load in GM crops and increasing global accept-
ance of GM crops by either eradicating SMGs or generating
selection marker-free GM crops [62].
SMGs Elimination Strategies Employed
in Rice
Using Co‑transformation
One of the earliest methods for producing transgenics
without the selectable marker is the co-transformation. It
involves transforming two or more genes (gene of interest
and selectable marker gene) simultaneously into the plant
genome. Using the same or different Agrobacterium, two
T-DNAs can be transformed into a single binary vector or
two binary vectors with one gene each [63–65]. Transfor-
mation using Agrobacterium and particle bombardment are
equally efficient to achieve desired results. However, particle
bombardment leads to the co-integration of T-DNAs at the
same genomic locus resulting in the linkage between gene
of interest and marker gene [66]. It requires multiple genera-
tions to remove the SMG, as it gets often linked with genes.
Further, this method is ineffective for transgenic trees with
longer generation time period and sterile plants. Parkhi et al.
utilizes two binary plasmids to successfully generate marker-
free carotenoids-rich transgenic rice (containing psy and crtI
gene encoding phytoene synthase and phytoene desaturase
respectively). The study reports 53.9% co-transformation
efficiency in transgenic rice employing hph and nptII as
selectable marker and gus as scorable marker [67]. Sripriya
et al., develops marker-free sheath blight resistant rice plant
carrying chitinase (chi11) gene using same method. To pro-
duce marker-free rice plants, an Agrobacterium strain with
a binary vector carrying the gene of interest (chi11) cloned
under the maize ubiquitin promoter and a co-integration vec-
tor with the marker gene (hph) is co-transformed. With a
co-transformation efficiency of 20%, segregation of the gene
of interest and the marker gene is achieved in
T1 generation
[68]. Ramana Rao et al. employ modified co-transformation
method to generate marker-free transgenic sheath blight
resistant rice cultivar by introducing two genes, chi11 and
ap24. chi11 encodes endochitinase whereas ap24 encodes
osmotin exhibiting antifungal activity against Phytoph-
thora infestans. T1 generation reveals effective separation
of SMG and gene of interest to different genetic loci with a
co-transformation efficiency of 67% [69]. The approach has
also been employed to generate marker-free insect resistant
transgenic Indica rice using hpt as SMG [70].
Using Site‑Specific Recombination
Site-specific recombination is the exchange of genetic mate-
rial between pairs of short, defined sequences at certain sites
[71]. In plants, numerous types of site-specific recombina-
tion systems have been employed to achieve marker-free
transgenics. These include CRE-loxP system from P1 bac-
teriophage, R/RS system from Zygosaccharomyces rouxii
[72–74] (Fig.1) and FLP/FRT from yeast, Saccharomyces
cerevisiae [75]. CRE-loxP system includes a CRE recom-
binase, and loxP recognition site. Two 13-bp loxP palindro-
mic sequences flanking a 7–12 bp core sequence are recog-
nised by CRE recombinase [76]. Site-specific recombinase
enzyme cleaves DNA at borders between recombinase bind-
ing elements and core sequence. CRE recombinase enzyme
recognise loxP recognition sites (flanking the selectable
marker gene) and execute DNA excision and recombina-
tion. CRE-loxP system has been used to develop marker-free
transgenic tobacco and rice by removing hpt gene [77, 78].
Sreekala et al. employ a chemically regulated CRE-loxP-
mediated site-specific recombination technique to create
marker-free rice transgenic plants in a single transforma-
tion. Out of 86 separate transgenic lines, 10 plants in the
T0
generation and 17 in T1 generation successfully segregate as
6. Molecular Biotechnology
1 3
marker-free plants [78]. Bai et al. generate marker-free trans-
genic rice by employing CRE-loxP system (with the cre gene
expressed under the Osmads45 promoter) and excising nptII
gene flanked by lox recombination sites at
T1 stage with
37.5% auto excision efficiency [79]. Sengupta et al. generate
marker-free transgenic rice resistant to sap sucking plan-
thoppers using CRE-loxP recombination technology. The
hpt marker gene cassette is cloned between the loxP sites in
vector harbouring Allium sativum leaf agglutinin encoding
gene. cre gene is cloned in a separate vector. Reciprocal
crosses between single-copy
T0 plants harbouring cre-bar
T-DNA and single-copy
T0 plants harbouring Allium sati-
vum leaf agglutinin -lox-hpt-lox T-DNA results in marker-
free T1 hybrids. The homozygous rice lines get subsequently
established in
T3 generation [80].
cre gene expressed under the soybean heat-shock pro-
moter in Nipponbare rice has been marked as an effective
strategy for conditional removal of marker gene in seed-
ling upon heat treatment [81]. Radhakrishnan and Srivas-
tava establishes FLP/FRT recombination system for rice
by deleting hpt gene from transformed plants [82]. FLP/
FRT recombination system has also been used to remove
nptII from GM rice [83]. Woo et al. develop marker-free
transgenic rice using an oxidative stress inducible FLP/FRT
based recombination system employing
H2O2. The system
involves a binary vector carrying codon optimized mFLP
(modified S. cerevisiae FLP with GC content) and hpt (as
SMG) between two FRT sites. The oxidative stress inducible
peroxidase promoter from sweet potato is used to express
both SMG and mFLP genes. Increased level of tocopherol
(due to overexpression of NtTc, Nicotiana tabacum cultivar
Xanthi tocopherol cyclase) assist in selection of transgen-
ics callus followed by segregation of marker gene by auto
excision. Compared to other methods, this technique elimi-
nates the need of additional chemical treatment or crossing
with recombinases to remove marker gene from transformed
rice plants [84]. Nandy and Srivastava develop marker-free
transgenic rice in
T0 generation by site-specific integra-
tion using FLP/FRT and CRE-loxP for marker elimination.
Marker-free site-specific integration (MF-SSI) is observed
in the first generation transgenic rice plant. CRE-loxP medi-
ated method to generate marker-free crop is most efficient
and stable method to transmit MF-SSI locus to next genera-
tion thereby producing marker-free first generation progeny
[85]. In another study thermostable FLP recombinase have
shown 100% excision efficiency in transgenic rice com-
pared to wild-type FLP recombinase (FLPwt), implying it
a significant step towards FLP-FRT based biotechnology in
plants [86].
Using Transposable Elements
Transposable elements are 100–1000 bases long sequences
involved in DNA repositioning in a genome. Barbara
McClintock identifies the first transposons, Ac/Ds family in
maize. Ac stands for activator element encoding transposase
and Ds stands for dissociation element. Transposase helps to
mobilize marker gene cloned between the inverted repeats of
Ds [87]. After the expression of the transposase, transpos-
able elements can be excised and re-insert in the genome.
The marker and gene of interest can be separated by plac-
ing the marker gene or gene of interest within the jumping
sequence. Because the marker gene is genetically unlinked
from the gene of interest, marker-free plants can be selected
after segregation. Due to the spectrum of positional effects
caused by re-insertion, a single transpositionally active
Fig. 1 SMG removal by site-specific recombination system. LB left border, T terminator, S selectable marker gene, P promoter, G gene of inter-
est, iP inducible promoter, R recombinase gene, RB right border [98]
7. Molecular Biotechnology
1 3
transformant line can demonstrate substantial qualitative
and quantitative diversity in gene expression levels [88].
However, reinsertion phenomenon can lower the impact of
marker gene removal and may enhance genome instability
in transgenics due to deletions, inverted duplications, inver-
sions, and translocations [89].
Cotsaftis et al. successfully develop marker-free trans-
genic Bt rice using transposable element-based approach.
This rice transformation study involves T-DNA carrying
cry1B gene under maize ubiquitin promoter flanked by
inverted terminal repeats of Ds cloned in the 5′untranslated
sequence of green fluorescent protein gene, an Ac trans-
posase and hph gene expressed under CaMV35S promoter.
The successful production of T-DNA free lines as a result
of Ds-cry1B relocation in the rice genome suggests this as
potent strategy for generating T-DNA free transgenic plants
[88]. Gao et al. also generate marker-free Bt-δ endotoxin
transgenic rice employing maize Ds element. The green
fluorescent protein gene acts as counter marker. Marker-free
progeny are identified in
T1 generation following unlinked
germinal transposition in 26.1% of primary transformants.
However, the method is time consuming, labour intensive,
as it requires crossing of transgenic plants and the selec-
tion of the marker-free progeny. This further depends on the
recovery rate of unlinked germinal transposition. Further,
probability of recombination can be enhanced by increasing
the population size of
T1 generation [90].
CRISPR/Cas9
Gene editing or manipulation has become much easier with
discovery of CRISPR/Cas9 system. The RNA based sys-
tem utilizes clustered regularly interspaced short palindro-
mic repeats (CRISPR) and Cas9 nuclease for editing tar-
geted gene. A simple guide RNA complementary to target
sequence scans the target DNA for a protospacer adjacent
motif [91]. For optimized gene expression, codon optimized
Cas9 is available for rice. CRISPR/Cas9 system has already
been employed for trait modification in O. sativa. Recently,
Srivastava et al. employs bi-allelic CRISPR based meth-
odology for excising gus (β-glucuronidase) gene from rice
genomes with precise cut and ligation of two blunt ends of
the gene. This method detected no mutation at or around
the excision site, a highly required goal of marker-removal
technologies for precise and unaltered excision of and
around target DNA [92]. Molecular analysis further reveals
significant excision frequency of this system amongst plant
lines compared to callus lines. Lu et al. propose the applica-
tion of CRISPR/Cas9 technology to promoter editing [93].
Wu et al. develop
H2O2 and 3,3-Diaminobenzidine based
high-throughput visual detection method to verify CRISPR/
Cas9 edited transgene-free rice plants. This study employ
polymerase chain reaction and 3,3-Diaminobenzidine stain-
ing to detect the difference in
H2O2 levels in transgenic rice
plant containing hpt gene from non-transgenic [94]. Toda
et al. attempt direct delivery of Cas9-gRNAs ribonucleopro-
teins (targeting DsRed2) into rice zygotes in transgenic rice
plants expressing DsRed2. DsRed2 expression is reduced in
zygotes and/or subsequent embryos when sgRNA in ribo-
nucleoproteins targets the DsRed2 sequence. As the method
uses plant zygotes it does not require selectable marker gene
to edit plant genome. Zygotes with decreased DsRed2 signal
regenerate in to mature plant in the absence of any selection
agents, with 14–64% showing targeted mutations. This study
highlights the enormous potential of this method in other
important crop too such as maize and wheat [95]. Dong
et al. develop marker-free transgenic carotenoid rich rice
using CRISPR/Cas9. The 5.2 kb marker-free carotenoid cas-
sette is inserted at genomic safe harbour regions in the plant
genome. Transformed dehusked seeds develop golden colour
due to the presence of carotenoids in endosperm compared
to wild type seeds [96]. Li et al. develop blight resistant
transgenic free rice. In this study, partial sequence of Xa13
promoter was edited by CRISPR/Cas9. This does not alter
the gene expression and function but alter its ability to get
induced by pathogen. This editing improves the rice abil-
ity to resist disease without affecting its fertility. PCR was
used to identify the mutation site induced by double target
sgRNA [97].
Conclusion
Rice, after wheat, is the world’s second-largest source of
human food energy. Innovative crop improvement technolo-
gies are need of the hour to meet the growing food demand
of the world’s population. This research focuses on advance-
ments in rice transgenics for enhanced traits, with a focus
on selection approaches that range from the use of existing
SMGs to selectable marker-free progenies. Popular first gen-
eration SMGs including hph, hpt, and nptII are regarded as
threat to humanity if not removed before reaching the con-
sumer. Second-generation selectable markers like as manA
and xylA have not yet been discovered as possibly detrimen-
tal to the environment, but they are still unappealing to con-
sumers. As a result, transgene-free plants are the most attrac-
tive and commercially acceptable. Since the first transgenic
crop was released in 1996, there has been an 87-fold increase
in the number of GM crops adopted around the world. Sev-
eral ways in combination with the CRISPR/Cas9 editing
tool, have been demonstrated as beneficial in rice genome
editing. This have been achieved either by removing SMGs
or by genome editing without the need of transgene integra-
tion. However, no such GM crop has yet been sold, leaving
plenty of room for experimentation. Similar rice engineering
8. Molecular Biotechnology
1 3
technologies could also help enhance molecular breeding for
superior cultivars in other important cereal crops.
Acknowledgements The authors would like to acknowledge Sci-
ence Technology Renewable Energy, UT Chandigarh [Grant No.
STRE/RP/147(21-22)/10/2021/956].
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