Determination of role of potential stress tolerance genes by RNAi directed silencing with special outline for betaine aldehyde dehydrogenase gene in rice
The different types of external stresses that influence the plant growth and development.
These stresses are grouped based on their characters
Biotic
Abiotic
Almost all the stresses, either directly or indirectly, lead to the production of reactive oxygen species (ROS) that create oxidative stress in plants.
This damages the cellular constituents of plants which are associated with a reduction in plant yield.
Improvement of Horticultural Crops for Abiotic Stress ToleranceEtalesh Goutam
This presentation was being presented by Etalesh Goutam (M.Sc. Horticulture; 2018-2020) in the master seminar at Department of Horticulture, H.N.B. Garhwal University, Srinagar (Garhwal) Uttarakhand- 246174
Organogenesis and somatic embryogenesis - In vitro mutant selection for bioti...Jyoti Prakash Sahoo
1. Direct embryogenesis
In direct somatic embryogenesis, the embryo is formed directly from a cell or small group of cells without the production of an intervening callus.
2. Indirect embryogenesis
In indirect somatic embryogenesis, callus is first produced from the explant.
Embryos can then be produced from the callus tissue or from a cell suspension produced from that callus.
The different types of external stresses that influence the plant growth and development.
These stresses are grouped based on their characters
Biotic
Abiotic
Almost all the stresses, either directly or indirectly, lead to the production of reactive oxygen species (ROS) that create oxidative stress in plants.
This damages the cellular constituents of plants which are associated with a reduction in plant yield.
Improvement of Horticultural Crops for Abiotic Stress ToleranceEtalesh Goutam
This presentation was being presented by Etalesh Goutam (M.Sc. Horticulture; 2018-2020) in the master seminar at Department of Horticulture, H.N.B. Garhwal University, Srinagar (Garhwal) Uttarakhand- 246174
Organogenesis and somatic embryogenesis - In vitro mutant selection for bioti...Jyoti Prakash Sahoo
1. Direct embryogenesis
In direct somatic embryogenesis, the embryo is formed directly from a cell or small group of cells without the production of an intervening callus.
2. Indirect embryogenesis
In indirect somatic embryogenesis, callus is first produced from the explant.
Embryos can then be produced from the callus tissue or from a cell suspension produced from that callus.
abiotic stress is imposing heavy loses in crop production. management practices cannot be a permanent solution for this problem. development of varieties with stress tolerance is an cost effective way to overcome abiotic stresses. for that studying the genetic basis is necessary
Cellular signal transduction pathways under abiotic stressSenthil Natesan
Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps (Knight & knight ,2001).Many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway (Miura and Furumoto,2013 ) . The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress (shi .et al ,2002). Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance (Nakashima and shinozaki, 2013) .ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response ( Mahajan,s and Tuteja, 2005) .
Plants are continually exposed to harsh environmental conditions which is life- threatening for their survival. Drought is one of the major environmental constraints that highly affect plant growth and productivity worldwide. Osmotic stress due to limited availability of water during drought lead to the inhibition of photosynthesis which ultimately affect plant growth, yield and productivity. As sessile in nature, plants cannot escape from such adverse situations. Hence, to cope up with these adverse situations, plants have developed a complex array of adaptive strategies including intricate regulation of cellular, physiological, biochemical and metabolic processes to avoid or tolerate cellular dehydration. Under limited water availability, stomata plays an essential role to check water loss due to transpiration. In addition, upon perception of stress signal, a wide range of signaling cascade has been activated which ultimately initiates the expression of stress-responsive genes in a timely and coordinated manner. Abscisic acid (ABA), the universal stress hormone, highly accumulated under stress condition, also plays an important role in stress adaptation including stomatal closure and expression of stress-responsive genes. In recent times, whole genome sequencing analysis of different plants reveals that a large family of genes is expressed under different types of abiotic stresses that are involved in defense-related pathways. These genes can be grouped into three categories, genes involving recognition of osmotic stress, signal perception, and transduction and production of stress-adaptive components for physiological responses.
Abiotic stress management for sustainable agriculturejayanta thokdar
Stress is an adverse force or a condition, which inhibits normal functioning in plants. An average of 50% yield losses in agricultural crops are caused by abiotic factors. To attain sustainability various crop management and breeding methods are employed to reduce impact of stress. Understand more about abiotic stress not only change our understanding of current environment, but also bring a plenty of benefits like improving sustainable agriculture and human beings living standards.
ROLE OF JASMONIC ACID IN PLANT DEVELOPMENT &DEFENCE MECHANISMBHU,Varanasi, INDIA
jasmonic acid is a plant immune hormone whicch are imortant for plant defence mechanism and development..its have important role in root growth inhibition,tuber formation,trichome formation ,senescence,flower developmentand increasing arbasculer mycorrhizal activity in root plants,recently it has been reported in various development in rice crop like spikelet development etc.....in defence its play a crucial role against insect and pathogen resistance.Recent insights into the JAs mediated plant defense cascade and better knowledge of key regulation of plant growth and development processes will help us to design future crops with increased biotic stress resistance and better adaptability under changing climate
Mechanisms of abiotic stress such as cold drought and salt stress which takes place in plants. Molecular control activities the plant undergoes during stress.
Prime-ome: "A molecular approach towards defense priming"Dhanya AJ
Prime-ome is the entire set of messenger RNA (mRNA) molécules or transcripts, proteins and metabolites produced or modified by an organism or system during the different stages of priming in plants and prime-omics is the study of prime-ome.
Keynote address at the InterDroughtIV Conference (2-6 Sep 2013) delivered on 2nd September 2013 by Jean-Marcel Ribaut, GCP Director, in Perth, Australia
Master's research proposal presentation to the department of Horticulture and Crop Science at The Ohio State University.
Abstract: Chile peppers (Capsicum annuum), which grow in southern Mexico on a environmental gradient from warm and humid coastal areas to the cool, dry highlands, present a unique opportunity to study the range of environmental tolerance and adaptation. Understanding how chile peppers have adapted to local conditions will provide insight into the importance of specific environmental factors in organizing diversity across the landscape, and highlight traits with potential for future crop improvement. Over recent years, our international research team has sampled more than 200 plants from wild, semi-wild and domesticated populations across southern Mexico. Seed from these original collections will undergo one generation of increase in the greenhouse to eliminate maternal environmental effects in seeds used for planned phenotyping experiments. Genome-wide genotyping (GBS) will be conducted on these parent plants. I will conduct two experiments aimed at assessing short-term and long-term resistance to abiotic stress. I will study short-term resistance to drought and heat stress in seedlings by overlaying factorial environmental treatments (simulating the interaction between cool highland/warm lowland temperatures and moist coastal/drier inland environments of Oaxaca, Mexico) onto chile pepper accessions from our collection. I will assess long-term (i.e. full life cycle) drought resistance by comparing the effect of a field capacity treatment with an empirically determined water stress treatment across accessions in factorial combination. Habitat drought stress indices based on the Thornthwaite potential evapotranspiration (PET) model and the Hamon estimator will be assessed as drought resistance predictors. Using a genome wide association study (GWAS) approach, I will identify significant associations between genetic markers and observed values of gas exchange, as well as plant morphology, growth characteristics and overall fitness. Information gathered through this study will provide evidence for the genetic basis of both adaptive variation and phenotypic plasticity, therefore furthering the understanding of genetic diversity in chile peppers.
abiotic stress is imposing heavy loses in crop production. management practices cannot be a permanent solution for this problem. development of varieties with stress tolerance is an cost effective way to overcome abiotic stresses. for that studying the genetic basis is necessary
Cellular signal transduction pathways under abiotic stressSenthil Natesan
Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps (Knight & knight ,2001).Many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway (Miura and Furumoto,2013 ) . The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress (shi .et al ,2002). Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance (Nakashima and shinozaki, 2013) .ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response ( Mahajan,s and Tuteja, 2005) .
Plants are continually exposed to harsh environmental conditions which is life- threatening for their survival. Drought is one of the major environmental constraints that highly affect plant growth and productivity worldwide. Osmotic stress due to limited availability of water during drought lead to the inhibition of photosynthesis which ultimately affect plant growth, yield and productivity. As sessile in nature, plants cannot escape from such adverse situations. Hence, to cope up with these adverse situations, plants have developed a complex array of adaptive strategies including intricate regulation of cellular, physiological, biochemical and metabolic processes to avoid or tolerate cellular dehydration. Under limited water availability, stomata plays an essential role to check water loss due to transpiration. In addition, upon perception of stress signal, a wide range of signaling cascade has been activated which ultimately initiates the expression of stress-responsive genes in a timely and coordinated manner. Abscisic acid (ABA), the universal stress hormone, highly accumulated under stress condition, also plays an important role in stress adaptation including stomatal closure and expression of stress-responsive genes. In recent times, whole genome sequencing analysis of different plants reveals that a large family of genes is expressed under different types of abiotic stresses that are involved in defense-related pathways. These genes can be grouped into three categories, genes involving recognition of osmotic stress, signal perception, and transduction and production of stress-adaptive components for physiological responses.
Abiotic stress management for sustainable agriculturejayanta thokdar
Stress is an adverse force or a condition, which inhibits normal functioning in plants. An average of 50% yield losses in agricultural crops are caused by abiotic factors. To attain sustainability various crop management and breeding methods are employed to reduce impact of stress. Understand more about abiotic stress not only change our understanding of current environment, but also bring a plenty of benefits like improving sustainable agriculture and human beings living standards.
ROLE OF JASMONIC ACID IN PLANT DEVELOPMENT &DEFENCE MECHANISMBHU,Varanasi, INDIA
jasmonic acid is a plant immune hormone whicch are imortant for plant defence mechanism and development..its have important role in root growth inhibition,tuber formation,trichome formation ,senescence,flower developmentand increasing arbasculer mycorrhizal activity in root plants,recently it has been reported in various development in rice crop like spikelet development etc.....in defence its play a crucial role against insect and pathogen resistance.Recent insights into the JAs mediated plant defense cascade and better knowledge of key regulation of plant growth and development processes will help us to design future crops with increased biotic stress resistance and better adaptability under changing climate
Mechanisms of abiotic stress such as cold drought and salt stress which takes place in plants. Molecular control activities the plant undergoes during stress.
Prime-ome: "A molecular approach towards defense priming"Dhanya AJ
Prime-ome is the entire set of messenger RNA (mRNA) molécules or transcripts, proteins and metabolites produced or modified by an organism or system during the different stages of priming in plants and prime-omics is the study of prime-ome.
Keynote address at the InterDroughtIV Conference (2-6 Sep 2013) delivered on 2nd September 2013 by Jean-Marcel Ribaut, GCP Director, in Perth, Australia
Master's research proposal presentation to the department of Horticulture and Crop Science at The Ohio State University.
Abstract: Chile peppers (Capsicum annuum), which grow in southern Mexico on a environmental gradient from warm and humid coastal areas to the cool, dry highlands, present a unique opportunity to study the range of environmental tolerance and adaptation. Understanding how chile peppers have adapted to local conditions will provide insight into the importance of specific environmental factors in organizing diversity across the landscape, and highlight traits with potential for future crop improvement. Over recent years, our international research team has sampled more than 200 plants from wild, semi-wild and domesticated populations across southern Mexico. Seed from these original collections will undergo one generation of increase in the greenhouse to eliminate maternal environmental effects in seeds used for planned phenotyping experiments. Genome-wide genotyping (GBS) will be conducted on these parent plants. I will conduct two experiments aimed at assessing short-term and long-term resistance to abiotic stress. I will study short-term resistance to drought and heat stress in seedlings by overlaying factorial environmental treatments (simulating the interaction between cool highland/warm lowland temperatures and moist coastal/drier inland environments of Oaxaca, Mexico) onto chile pepper accessions from our collection. I will assess long-term (i.e. full life cycle) drought resistance by comparing the effect of a field capacity treatment with an empirically determined water stress treatment across accessions in factorial combination. Habitat drought stress indices based on the Thornthwaite potential evapotranspiration (PET) model and the Hamon estimator will be assessed as drought resistance predictors. Using a genome wide association study (GWAS) approach, I will identify significant associations between genetic markers and observed values of gas exchange, as well as plant morphology, growth characteristics and overall fitness. Information gathered through this study will provide evidence for the genetic basis of both adaptive variation and phenotypic plasticity, therefore furthering the understanding of genetic diversity in chile peppers.
Mechanisms of adaptation to drought and waterlogging in Brachiaria grassesCIAT
Drought and waterlogging are major abiotic stresses that limit the productivity of Brachiaria forage grasses. Little attention has been given to separate productivity under drought or waterlogging, from coping mechanisms in Brachiaria forage grasses. Wide phenotypic variation exists among Brachiaria grasses to cope with these stresses. This presentation will cover : 1) the current knowledge of morpho-physiological mechanisms and functional adaptations of Brachiaria spp cultivars to cope with these stresses and 2) the use of sensors and digital image analysis for the non-destructive and automated analysis of Brachiaria growth and performance at different time scales.
Comparative analysis of some biochemical responses of winter and spring wheat...Innspub Net
To compare changes of biochemical indices between spring (Kavir) and winter (Azar2) cultivars of wheat (Triticum aestivum L.) under low temperature, 14 days old wheat seedlings were exposed to cold. The seedlings were transferred into growth chamber for 9 days at 5/3 °C (day/night) as cold treatment, or at 20/18 °C as control. Proline content, total protein accumulation, activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) enzymes, were assayed in the leaf extracts of control and cold treated plants. The results showed that cold led to an accumulation of proline and an increase in protein level, especially in winter cultivar. Rapid increases in proline and protein accumulations were observed during early stages of cold stress. SOD activity displayed no significant differences between the two cultivars during the first 3 days after cold stress, while in Azar 2, the level of SOD activity was gradually increased after 3 days of cold stress. The POD and CAT activity were higher in plants grown at cold stress than in the controls; however, their rate was different in winter and spring wheat cultivars. In general, Azar2 showed relatively higher POD and CAT activity compared to Kavir. Regarding antioxidant enzymes activities, cultivars respond differently under cold stress. Articles source: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/
Plant phenolics in animal health and methane mitigation. avijit deyAvijit Dey
Phenolics are ubiquitous in all plant organs and integral part of animal and human foods. Phenolic acids, flavanoids and tannins are the most common phenolic compounds. Fruits and vegetables are rich source of polyphenols for humans. Whereas, tree leaves in tropical countries are potential sources phenolic compounds for animals. Researchers have become more interested in polyphenols due to their potent antioxidant properties and credible effects in the prevention of cardiovascular, neurodegenerative diseases and cancer. Condensed tannins (CT) and flavanoids have the ability to modify the rumen fermentation towards reduced methanogenesis by altering rumen microbial community and their supplementation reduces nitrogen excretion in ruminants by improving its utilization efficiency. Improvement in feed intake, growth rate, wool production, reproduction and milk production in ruminants fed CT containing diets were observed in a dose dependent manner. In ruminants, most proteins are rapidly solubilised and release 56- 65% N in the rumen during mastication; consequently large losses of N (25-35%) occur as ammonia absorbed from rumen. CT from tree leaves could be used as organic protectant of proteins to improve protein utilization by ruminants and reduce environmental pollution by minimising N losses through urine. Supplementation of CT through leaves of Artocarpus heterophyllus, Ficus infectoria, Ficus bengalensis and Ficus glomerata at 1.5- 2.0% levels was observed to reduce the rumen degradability of groundnut cake to 60-75 per cent from the normal value of 92 per cent. Controlling gastro-intestinal parasites by supplementation of CT through F. infectoria, Psidium guajava and Ficus bengalensis was effective to ameliorate drug resistance. Feeding study to lambs and crossbred cows with supplementation of CT (1.5%) either through F. Infectoria and F. bengalensis leaves was found to increase feed efficiency, growth rate, milk yield, fat yield, antioxidant status and immunity of animals. Flavanoids and tannin-rich feeds could reduce or inhibit rumen biohydrogenation of vaccenic acid to stearic acid, resulting in the accumulation of conjugated linoleic acids (CLA) in milk and meat which has hypolipidaemic and anti carcinogenic effects in humans. Judicious application of plant phenolics could improve overall health and production performance of animals.
Similar to RNAi-DIRECTED SILENCING OF POTENT STRESS TOLERANT GENE(S) AND ITS EFFECT ON STRESS TOLERANCE IN PLANTS (20)
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
3. RNA interference(RNAi)
A general endogenous mechanism in many organisms including plant that is used to
silence the expression of the genes that control various events in the cell
In 1990, In an attempt to enhance the flower color in petunias, researchers introduced
additional copies of a gene encoding chalcone synthase
Over expressed gene was expected to result in darker flowers, but instead produced less
pigmented, fully or partially white flowers
Andrew Fire and Craig C. Mello shared 2006 Nobel Award in Medicine or Physiology for
their work in RNA interference in Caenorhabditis elegans
Micro ribonucleic acid (miRNA) and small interfering RNA (siRNA) are central to RNA
interference
3
4. 4
Advantages:
• This natural mechanism for sequence-specific gene silencing may have important
practical application in functional genomics, therapeutic intervention, agriculture
and other areas
• RNA interference provides defence to the cell against parasitic nucleotide
sequence e.g. virus
•RNA interference can also be mediated artificially by inserting a dsRNA into the
cell
5. 5
Effect of stress on plants
Biotic stress: is imposed by other organism
Abiotic stress: arises from an excess or deficit of the physical or
chemical environment like drought, water logging, excess low
temperature or high temperature and excess soil salinity
Abiotic factors provide the major limitation to crop production worldwide
Affects plant growth and development
Therefore there is need of stress resistance in plants
Stress resistance or sensitivity depends on the genotype, species and
developmental age of the plant
6. Glycine Betaine (GB): as an osmoprotectant
6
N,N,N- trimethylglycine (GB) is an amphoteric quarternary amine
Provides osmotic adjustment to the plant under stressed condition
GB is synthesized in plants through a two stepped process
Choline monooxygenase (CMO) and Betaine aldehyde
dehydrogenase (BADH) enzyme catalyze the first and second step
respectively
Rice (Oryza sativa) has two homologs of BADH gene.viz-BADH1
and BADH2
9. OBJECTIVE
S
To demonstrate a pivotal role of OsBADH1 in stress tolerance using
RNA interference technology (RNAi) without affecting GB biosynthesis
capacity
Stress tolerance analysis of japonica transgenic lines downregulating
OsBADH1 by giving NaCl, drought and cold stress treatments
9
10. METHODOLOG
Y
Full length cloning of OsBADH1 cDNA
Construction of pHB-OsBADH1-RNAi expression plasmid
Analysis of gene expression of OsBADH1 by reverse transcription-
quantitative real time PCR (RT-q PCR)
Identification of japonica transgenic plants
10
11. 11
METHODOLOG
Y
Analysis of BADH activity
Assay of tolerance to abiotic stress
Assay of MDA and H2O2
• using leaf tissues
Determination of glycine betaine (GB)
12. Fig. 1 Expression pattern of OsBADH1 in various tissues.
•Expression abundance in root, stem, leaf, internodes, immature flower,
seedling leaf and seedling root of a japonica rice variety Nippobare is shown
RESULT AND DISCUSSION
12
13. Figure 2: Semi-quantitative and real-time qPCR analyses of (A)OSBADH1,
(B) OSBADH2 and (C) Expression levels of OsBADH1 and OsBADH2 of
transene positive and negative were indicated comparing with the internal
control Actin 13
14. Figure3: Shows the
BADH activity in
transgene positive
and transgene
negative plant leaves
by using (D) betaine
aldehyde and (E)
acetaldehyde
respectively
14
15. Figure4: Abiotic stress tolerance of OsBADH1-RNAi transgenic rice.
(A)0 mM NaCl, (B) 50 mM NaCl, (C) 100 mM
NaCl, (D) 200 mM mannitol, (E) 300 mM mannitol and (F) cold (4 °C)
15
16. Figure 5: Measurements of (A) root length (B) shoot length (C) seedling
weight (c) in transgene-negative plants (WT) and transgene-positive plants (B1-a,
B1-c,B1-e)
• The asterisk (*) above each column indicates there was a significant difference
(p< 0.05) between transgene- positive and transgene – negative plants
16
17. Figure 6: The phenotype of OsBADH1-RNAi transgenic
Rice (B1-a, B1-c, B1-e) and wild type (WT)
(A)before 100 mM NaCl treatment
(B) under 100 mM NaCl treatment
(C) Primary plants in field 17
18. Figure 7 : Detection of salt/ drought/ cold stress-induced H2O2 production by
Diaminobenzidiene (DAB) staining in leaves of transgene negative (WT) and
transgene positive plants (B1-a,B1-c,B1-e)
18
19. Figure8: Malondialdehyde (MDA) contents in the leaves of transgene negative
(WT) and transgene positive plants (B1-a,B1-c,B1-e)
• The asterisk(*) above each column indicates a significant difference (P < 0.05)
between WT and BI-a, B1-c,B1-e
19
20. Figure 9: The (A) unhusked and (B) husked grains of transgene-negative (WT)
and transgene positive plants (B1-a,B1-C,B1-e)
20
21. 21
Highest expression of OsBADH1 gene in roots and leaves, least expression
level in stem (figure1)
reduced abiotic stress tolerance and crop productivity in OsBADH1
Downregulated plants (figure 4,5,6 and 9)
Glycine betaine (GB) content was not affected (figure 3)
The downregulation of OsBADH1 altered the ROS scavenging capacity of the
transgenic plant without changing GB content (figure 7 and 8)
Therefore OsBADH1 has a pivotal role in stress tolerance without altering
GB (Glycine betaine) biosynthesis capacity
22. 22
CONCLUSION
OsBADH1 gene confers stress tolerance and also increase crop
productivity
Downregulation of OsBADH1 gene significantly alters scavanging of
ROS(reactive oxygen species) like H2O2 and lipid perozidation product
like MDA
Therefore, it can be concluded that OsBADH1 gene is very
essential for stress tolerance and crop productivity of rice plant
23. REFERENCES
1. Hasthanasombut S, Supaibulwatana K (2011) Genetic manipulation
of Japonica rice using the OsBADH1 gene from Indica rice
to improve salinity tolerance. Plant Cell Tissue and organ cult
104:79–89.
2. Hasthanasombut S, Ntui V, Supaibulwatana K (2010) Expression of
Indica rice OsBADH1 gene under salinity stress in transgenic
tobacco. Plant Biotechnol Rep 4:75–83.
3. Huang W, Ma X, Wang Q, Gao YF, Xue Y, Niu XL, Yu GY, Liu YS
(2008) Significant improvement of stress tolerance in tobacco
plants by overexpressing a stress-responsive aldehyde dehydrogenase
gene from maize (Zea mays). Plant Mol Biol 68:451–463.
23
24. 4. Luo D, Niu X, Yu J, Yan J, Gou X, Lu BR, Liu YS (2012) Rice choline
monooxygenase (OsCMO) protein functions in enhancing
glycine betaine biosynthesis in transgenic tobacco but does not
accumulate in rice (Oryza sativa L. ssp. japonica). Plant Cell Rep
31:1625–1635.
5. Hasthanasombut S, Supaibulwatana K (2011) Genetic manipulation
of Japonica rice using the OsBADH1 gene from Indica rice
to improve salinity tolerance. Plant Cell Tissue and organ cult
104:79–89.
6. Hasthanasombut S, Ntui V, Supaibulwatana K (2010) Expression of
Indica rice OsBADH1 gene under salinity stress in transgenic
tobacco. Plant Biotechnol Rep 4:75–83.
24
