Flower development in Arabidopsis thaliana is controlled by several key gene pathways. Flowering time genes determine how long the plant remains in a vegetative state before flowering. At least five pathways interact to control flowering time in response to factors like photoperiod and vernalization. Floral identity genes such as LFY, AP1, AP2, and CAL control the transition of shoot meristems into floral meristems and developing flowers. Organ identity genes including AP1, AP2, AP3, PI, and AG specify the development of floral organs into sepals, petals, stamens or carpels. Mutations in these genes disrupt normal flower development.
This document discusses gibberellins, a class of plant hormones. It was first discovered in 1928 by a Japanese scientist who observed rice plants infected by the fungus Gibberella fujikuroi showed excessive stem elongation. There are over 70 known forms of gibberellins that regulate various plant developmental processes such as stem elongation, germination, flowering, and fruit development. Gibberellins are widely distributed in plants and are involved in many physiological roles including stem elongation, bolting, seed germination, breaking bud and tuber dormancy, parthenocarpy, and flowering.
Phenomenon and factors of infection in plants nishakataria10
This document discusses the phenomenon of plant infection and methods to control plant diseases. It describes the three phases of pathogenesis in plants: pre-penetration, penetration, and post-penetration. It then lists and explains various biological agents that can infect plants, such as fungi, bacteria, viruses, and nematodes. Finally, it outlines four main methods to control plant diseases: cultural, physical, chemical, and plant quarantine methods.
The document discusses breeding for disease resistance in pearl millet. It covers four main fungal diseases that impact pearl millet production: downy mildew, ergot, smut, and rust. For downy mildew, it describes screening techniques, major resistance sources identified, and genetics of resistance, noting that resistance is governed by major genes following a gene-for-gene relationship between host and pathogen.
Distant hybridization involves crossing individuals from different plant species or genera. It has been used to transfer desirable traits like disease resistance between crops. Some key challenges include hybrid sterility and incompatible crosses due to genetic differences between parental species. Techniques like embryo rescue and colchicine treatment have helped produce new crops through wide crosses, such as Nerica rice and triticale wheat-rye hybrids. Distant hybridization remains limited by barriers like hybrid breakdown but has achieved successes in improving crop varieties.
The document summarizes the ABC model of flower development. It discusses (a) the transition from vegetative to reproductive phase controlled by genes like FT, LFY, and SOC1, (b) the formation of inflorescence meristems regulated by genes like WUS and STM that prevent stem cell differentiation, and (c) individual floral organ development governed by meristem identity, organ identity, and cadastral genes. The ABC model specifies floral organ identity through the combinatorial interactions of ABC genes like AP3, PI, AG, and AP2, and D class genes like FBP7 control ovule development. The ABC model is sufficient to convert meristems into flowers and applies broadly across flowering plants.
1. The ABC model proposes that floral organ identity is specified by three classes of organ-identity genes (A, B, and C) that function in overlapping domains within a flower to determine the four whorls.
2. Class A genes like AP1 specify sepals and petals, class B genes like AP3 and PI specify petals and stamens, and the class C gene AG specifies stamens and carpels.
3. Studies on floral organ development mutants and gene expression patterns provided strong support for the ABC model, but it was later expanded to include class E genes like SEP that work together with the ABC genes to specify organ identity in each whorl.
Flower development in Arabidopsis thaliana is controlled by several key gene pathways. Flowering time genes determine how long the plant remains in a vegetative state before flowering. At least five pathways interact to control flowering time in response to factors like photoperiod and vernalization. Floral identity genes such as LFY, AP1, AP2, and CAL control the transition of shoot meristems into floral meristems and developing flowers. Organ identity genes including AP1, AP2, AP3, PI, and AG specify the development of floral organs into sepals, petals, stamens or carpels. Mutations in these genes disrupt normal flower development.
This document discusses gibberellins, a class of plant hormones. It was first discovered in 1928 by a Japanese scientist who observed rice plants infected by the fungus Gibberella fujikuroi showed excessive stem elongation. There are over 70 known forms of gibberellins that regulate various plant developmental processes such as stem elongation, germination, flowering, and fruit development. Gibberellins are widely distributed in plants and are involved in many physiological roles including stem elongation, bolting, seed germination, breaking bud and tuber dormancy, parthenocarpy, and flowering.
Phenomenon and factors of infection in plants nishakataria10
This document discusses the phenomenon of plant infection and methods to control plant diseases. It describes the three phases of pathogenesis in plants: pre-penetration, penetration, and post-penetration. It then lists and explains various biological agents that can infect plants, such as fungi, bacteria, viruses, and nematodes. Finally, it outlines four main methods to control plant diseases: cultural, physical, chemical, and plant quarantine methods.
The document discusses breeding for disease resistance in pearl millet. It covers four main fungal diseases that impact pearl millet production: downy mildew, ergot, smut, and rust. For downy mildew, it describes screening techniques, major resistance sources identified, and genetics of resistance, noting that resistance is governed by major genes following a gene-for-gene relationship between host and pathogen.
Distant hybridization involves crossing individuals from different plant species or genera. It has been used to transfer desirable traits like disease resistance between crops. Some key challenges include hybrid sterility and incompatible crosses due to genetic differences between parental species. Techniques like embryo rescue and colchicine treatment have helped produce new crops through wide crosses, such as Nerica rice and triticale wheat-rye hybrids. Distant hybridization remains limited by barriers like hybrid breakdown but has achieved successes in improving crop varieties.
The document summarizes the ABC model of flower development. It discusses (a) the transition from vegetative to reproductive phase controlled by genes like FT, LFY, and SOC1, (b) the formation of inflorescence meristems regulated by genes like WUS and STM that prevent stem cell differentiation, and (c) individual floral organ development governed by meristem identity, organ identity, and cadastral genes. The ABC model specifies floral organ identity through the combinatorial interactions of ABC genes like AP3, PI, AG, and AP2, and D class genes like FBP7 control ovule development. The ABC model is sufficient to convert meristems into flowers and applies broadly across flowering plants.
1. The ABC model proposes that floral organ identity is specified by three classes of organ-identity genes (A, B, and C) that function in overlapping domains within a flower to determine the four whorls.
2. Class A genes like AP1 specify sepals and petals, class B genes like AP3 and PI specify petals and stamens, and the class C gene AG specifies stamens and carpels.
3. Studies on floral organ development mutants and gene expression patterns provided strong support for the ABC model, but it was later expanded to include class E genes like SEP that work together with the ABC genes to specify organ identity in each whorl.
This document discusses different types of plant organ culture, including root, shoot apical meristem, leaf, flower, and ovule cultures. Root culture involves culturing excised radical tips of aseptically germinated seeds. Shoot apical meristem culture involves culturing the shoot tip comprising the meristem and developing leaves. Flower culture involves culturing excised floral buds to produce full blooms. Ovule culture involves culturing isolated ovules to facilitate fertilization and embryo development. Organ cultures have various applications including studying organ development, production of secondary metabolites, and generating virus-free plants.
Auxin is the first plant hormone discovered. It is produced throughout the plant and regulates many growth processes. There are two main pathways for auxin (IAA) biosynthesis - tryptophan-dependent and tryptophan-independent. Auxin's mechanism of action involves binding to receptor proteins and promoting proton pumping, which acidifies the cell wall and activates expansin proteins, leading to cell wall loosening and elongation. The physiological effects of auxin include stimulating cell elongation, controlling apical dominance, initiating root formation, preventing abscission, and promoting callus growth and vascular differentiation.
after floral induction, the inflorescence meristem eventually forms the floral meristem. the process is controlled by an array of homeotic genes. this also involves microRNAs for their regulation
This document discusses several major plant hormones (phytohormones), including their functions, locations of synthesis, and some uses. It describes auxins, cytokinins, gibberellins, abscisic acid, and ethylene - noting that they regulate growth, stress responses, germination, flowering, and fruit development. Specific hormones are discussed in more detail, outlining their natural and synthetic forms as well as some of their roles and applications in agriculture.
Gibberellins are tetracyclic diterpenoid plant hormones that were first discovered in Japan when investigating a fungus that caused abnormal growth in rice plants. There are currently 136 identified gibberellins derived from plants, fungi, and bacteria. Gibberellins promote stem elongation, seed germination, and flower induction. They are synthesized in the leaves and transported to other parts of the plant where they stimulate growth and developmental processes.
Flower development is controlled by floral developmental genes that are induced in response to environmental signals like photoperiod and temperature. The ABC model describes how MADS-box transcription factors encoded by ABC genes control floral organ identity in four whorls. Class A genes specify sepals, Class B genes specify petals, Class C genes specify stamens, and the combination of B and C genes specify carpels. Mutations in these ABC genes result in homeotic transformations of floral organs. The ABC model was later expanded to the ABCDE model with the addition of SEPALLATA genes that act redundantly with ABC genes.
This document summarizes research on somatic embryogenesis in rice. It describes the process of somatic embryogenesis, including the stages of embryogenesis and factors that affect it. The methodology section outlines the materials and methods used, including collecting rice seeds as explants, sterilizing them, and culturing them on callus induction and embryo germination media with different concentrations of plant growth regulators like 2,4-D, BAP and NAA. The goal is to develop an efficient system for somatic embryogenesis and plant regeneration in rice.
Angiosperm (seed formation and development)Daisy Capon
Daisy Capon is a PhD student studying crop science. Her research focuses on angiosperm seed formation and development. She outlines the key stages of male and female gametophyte development, including microsporogenesis, microgametogenesis, megasporogenesis, and megagametogenesis. She then discusses seed formation, including the roles of the integuments, nucellus, and embryo sac. The structures and development of plant embryos are also examined, from fertilization through the cotyledon, hypocotyl, and radicle stages. Finally, she analyzes the chemical composition of seeds and factors that affect it.
Dormancy, germination, and seed developmentAYAK SILAS
Seed development begins with fertilization and involves the growth of the embryo and endosperm within the ovule. As development progresses, the ovule expands and its tissues differentiate into protective seed coat layers. The embryo develops organs and is nourished by the endosperm. Seed germination occurs when environmental conditions allow the embryo to resume growth, rupturing the seed coat and developing a root and shoot. Key factors influencing germination include temperature, moisture, soil minerals, and light. Germination can be epigeal, where the hypocotyl and cotyledons emerge above ground, or hypogeal, where only the hypocotyl emerges while the cotyledons remain below ground.
ABC model of flower development crop repro physionea killuae
The document discusses the ABC model of flower development. The ABC model proposes that three classes of genes (A, B, and C) interact to specify the four types of floral organs in flowers. Class A genes specify sepals, Class A and B genes together specify petals, Class B and C genes together specify stamens, and Class C genes specify carpels. Mutations in these genes result in homeotic transformations where one organ develops in the place of another. The ABC model was formulated based on studies of gene expression and mutants in Arabidopsis thaliana and Antirrhinum majus.
Brassinosteroids are a class of plant steroid hormones that were first discovered in rapeseed pollen in the 1960s. They influence many developmental processes similar to auxins. The most common brassinosteroid is brassinolide, which was first isolated from rapeseed in 1979. Brassinosteroids regulate processes like cell elongation, flowering, vascular development, photomorphogenesis, and stress tolerance. They are perceived by membrane receptors and signal through a phosphorylation cascade to regulate gene expression.
Biosynthesis and function of the plant hormone auxin is summarized in 3 sentences:
Auxin is synthesized from tryptophan via the IPyA or acetonitrile pathways, and promotes cell elongation and differentiation, phototropism, and apical dominance. It signals through the SCFTIR1/AFB pathway to degrade Aux/IAA repressors and activate ARF transcription factors. Polar auxin transport, mediated by PIN and ABCB transporters, directs auxin flows throughout the plant to regulate growth responses.
In vitro Production of Haploid Plants by Anther & Pollen Cultures SMGsajigeorge64
Anther culture is an in vitro technique where anthers are cultured in nutrient media to produce haploid plants. In 1964, two Indian scientists cultured anthers of Datura innoxia and produced the first haploid plants using this method. Anther culture involves removing anthers from flower buds, culturing them, and inducing microspores or pollen grains to develop into haploid plants through androgenesis rather than the normal gametophytic pathway. It has been successful in producing haploids in families such as Solanaceae, Brassicaceae, and Poaceae. The technique provides applications in genetics, breeding, and crop improvement.
Flowering in plants(Arabidopsis) ABC ModelFreya Cardozo
Flowering in plants(Arabidopsis) ABC Model
My youtube videos:
https://youtu.be/9SxSpNEQj_g
https://youtu.be/-D6OGm8YbXc
Set of four genes class A, B & C are involved in giving identity of different whorls. 4 pathways are involved - Photoperiodism, autonomous pathway, vernalization & giberlleic acid
This presentation describes about the dormancy, types of dormancy (seed dormancy and bud dormancy) as well as methods to overcome the bud and seed dormancy in detail.
This document discusses various methods for germline transformation in plants. It begins with introducing germline transformation as the process of altering an organism's genetic makeup by inserting new DNA into its genome, usually using vectors like plasmids. It then describes several methods for accomplishing plant transformation, including the pollen tube pathway method, Agrobacterium-mediated method, electrofusion, floral dip method, and biolistic method. The document provides details on the history and protocol of the pollen tube pathway method for plant transformation.
Modern techniques of crop improvement.pptx finalDr Anjani Kumar
This document discusses modern techniques for crop improvement, including genome editing, gene silencing, cisgenics, site directed mutagenesis, and programmed cell death. It begins with an introduction noting the increasing global population and need to improve crop yields. Genome editing uses engineered nucleases to insert, delete, or replace DNA in living organisms. CRISPR/Cas9 is highlighted as a powerful and precise genome editing technique. Gene silencing techniques like RNA interference can be used to "switch off" genes and improve crop traits. These modern techniques allow for more targeted genetic modifications of crops compared to traditional breeding methods and have potential for meeting future agricultural demands.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms for those who already suffer from conditions like anxiety and depression.
The plant hormone abscisic acid (ABA) plays a key role in mediating plant adaptation to stress. It induces stomatal closure to reduce water loss during drought, inhibits cell growth and seed germination to enforce seed dormancy, and promotes bud dormancy and the development of bud scales during winter. ABA is produced in response to decreased soil water availability and other stressors, then translocates to leaves and buds to trigger adaptive responses that prevent water loss and allow plants to survive potentially harmful conditions like drought and winter.
The plant hormone abscisic acid (ABA) mediates plant adaptation to stress by inducing stomatal closure to reduce water loss, inhibiting cell growth and seed germination to promote dormancy, and regulating bud formation and abscission. ABA is produced in response to stresses like drought, cold temperatures, and soil compaction and translocates from roots to leaves to trigger closing of stomata and reduce transpiration. It plays important roles in enforcing bud and seed dormancy, inhibiting seedling growth, and preventing premature sprouting or germination until conditions are suitable.
This document discusses different types of plant organ culture, including root, shoot apical meristem, leaf, flower, and ovule cultures. Root culture involves culturing excised radical tips of aseptically germinated seeds. Shoot apical meristem culture involves culturing the shoot tip comprising the meristem and developing leaves. Flower culture involves culturing excised floral buds to produce full blooms. Ovule culture involves culturing isolated ovules to facilitate fertilization and embryo development. Organ cultures have various applications including studying organ development, production of secondary metabolites, and generating virus-free plants.
Auxin is the first plant hormone discovered. It is produced throughout the plant and regulates many growth processes. There are two main pathways for auxin (IAA) biosynthesis - tryptophan-dependent and tryptophan-independent. Auxin's mechanism of action involves binding to receptor proteins and promoting proton pumping, which acidifies the cell wall and activates expansin proteins, leading to cell wall loosening and elongation. The physiological effects of auxin include stimulating cell elongation, controlling apical dominance, initiating root formation, preventing abscission, and promoting callus growth and vascular differentiation.
after floral induction, the inflorescence meristem eventually forms the floral meristem. the process is controlled by an array of homeotic genes. this also involves microRNAs for their regulation
This document discusses several major plant hormones (phytohormones), including their functions, locations of synthesis, and some uses. It describes auxins, cytokinins, gibberellins, abscisic acid, and ethylene - noting that they regulate growth, stress responses, germination, flowering, and fruit development. Specific hormones are discussed in more detail, outlining their natural and synthetic forms as well as some of their roles and applications in agriculture.
Gibberellins are tetracyclic diterpenoid plant hormones that were first discovered in Japan when investigating a fungus that caused abnormal growth in rice plants. There are currently 136 identified gibberellins derived from plants, fungi, and bacteria. Gibberellins promote stem elongation, seed germination, and flower induction. They are synthesized in the leaves and transported to other parts of the plant where they stimulate growth and developmental processes.
Flower development is controlled by floral developmental genes that are induced in response to environmental signals like photoperiod and temperature. The ABC model describes how MADS-box transcription factors encoded by ABC genes control floral organ identity in four whorls. Class A genes specify sepals, Class B genes specify petals, Class C genes specify stamens, and the combination of B and C genes specify carpels. Mutations in these ABC genes result in homeotic transformations of floral organs. The ABC model was later expanded to the ABCDE model with the addition of SEPALLATA genes that act redundantly with ABC genes.
This document summarizes research on somatic embryogenesis in rice. It describes the process of somatic embryogenesis, including the stages of embryogenesis and factors that affect it. The methodology section outlines the materials and methods used, including collecting rice seeds as explants, sterilizing them, and culturing them on callus induction and embryo germination media with different concentrations of plant growth regulators like 2,4-D, BAP and NAA. The goal is to develop an efficient system for somatic embryogenesis and plant regeneration in rice.
Angiosperm (seed formation and development)Daisy Capon
Daisy Capon is a PhD student studying crop science. Her research focuses on angiosperm seed formation and development. She outlines the key stages of male and female gametophyte development, including microsporogenesis, microgametogenesis, megasporogenesis, and megagametogenesis. She then discusses seed formation, including the roles of the integuments, nucellus, and embryo sac. The structures and development of plant embryos are also examined, from fertilization through the cotyledon, hypocotyl, and radicle stages. Finally, she analyzes the chemical composition of seeds and factors that affect it.
Dormancy, germination, and seed developmentAYAK SILAS
Seed development begins with fertilization and involves the growth of the embryo and endosperm within the ovule. As development progresses, the ovule expands and its tissues differentiate into protective seed coat layers. The embryo develops organs and is nourished by the endosperm. Seed germination occurs when environmental conditions allow the embryo to resume growth, rupturing the seed coat and developing a root and shoot. Key factors influencing germination include temperature, moisture, soil minerals, and light. Germination can be epigeal, where the hypocotyl and cotyledons emerge above ground, or hypogeal, where only the hypocotyl emerges while the cotyledons remain below ground.
ABC model of flower development crop repro physionea killuae
The document discusses the ABC model of flower development. The ABC model proposes that three classes of genes (A, B, and C) interact to specify the four types of floral organs in flowers. Class A genes specify sepals, Class A and B genes together specify petals, Class B and C genes together specify stamens, and Class C genes specify carpels. Mutations in these genes result in homeotic transformations where one organ develops in the place of another. The ABC model was formulated based on studies of gene expression and mutants in Arabidopsis thaliana and Antirrhinum majus.
Brassinosteroids are a class of plant steroid hormones that were first discovered in rapeseed pollen in the 1960s. They influence many developmental processes similar to auxins. The most common brassinosteroid is brassinolide, which was first isolated from rapeseed in 1979. Brassinosteroids regulate processes like cell elongation, flowering, vascular development, photomorphogenesis, and stress tolerance. They are perceived by membrane receptors and signal through a phosphorylation cascade to regulate gene expression.
Biosynthesis and function of the plant hormone auxin is summarized in 3 sentences:
Auxin is synthesized from tryptophan via the IPyA or acetonitrile pathways, and promotes cell elongation and differentiation, phototropism, and apical dominance. It signals through the SCFTIR1/AFB pathway to degrade Aux/IAA repressors and activate ARF transcription factors. Polar auxin transport, mediated by PIN and ABCB transporters, directs auxin flows throughout the plant to regulate growth responses.
In vitro Production of Haploid Plants by Anther & Pollen Cultures SMGsajigeorge64
Anther culture is an in vitro technique where anthers are cultured in nutrient media to produce haploid plants. In 1964, two Indian scientists cultured anthers of Datura innoxia and produced the first haploid plants using this method. Anther culture involves removing anthers from flower buds, culturing them, and inducing microspores or pollen grains to develop into haploid plants through androgenesis rather than the normal gametophytic pathway. It has been successful in producing haploids in families such as Solanaceae, Brassicaceae, and Poaceae. The technique provides applications in genetics, breeding, and crop improvement.
Flowering in plants(Arabidopsis) ABC ModelFreya Cardozo
Flowering in plants(Arabidopsis) ABC Model
My youtube videos:
https://youtu.be/9SxSpNEQj_g
https://youtu.be/-D6OGm8YbXc
Set of four genes class A, B & C are involved in giving identity of different whorls. 4 pathways are involved - Photoperiodism, autonomous pathway, vernalization & giberlleic acid
This presentation describes about the dormancy, types of dormancy (seed dormancy and bud dormancy) as well as methods to overcome the bud and seed dormancy in detail.
This document discusses various methods for germline transformation in plants. It begins with introducing germline transformation as the process of altering an organism's genetic makeup by inserting new DNA into its genome, usually using vectors like plasmids. It then describes several methods for accomplishing plant transformation, including the pollen tube pathway method, Agrobacterium-mediated method, electrofusion, floral dip method, and biolistic method. The document provides details on the history and protocol of the pollen tube pathway method for plant transformation.
Modern techniques of crop improvement.pptx finalDr Anjani Kumar
This document discusses modern techniques for crop improvement, including genome editing, gene silencing, cisgenics, site directed mutagenesis, and programmed cell death. It begins with an introduction noting the increasing global population and need to improve crop yields. Genome editing uses engineered nucleases to insert, delete, or replace DNA in living organisms. CRISPR/Cas9 is highlighted as a powerful and precise genome editing technique. Gene silencing techniques like RNA interference can be used to "switch off" genes and improve crop traits. These modern techniques allow for more targeted genetic modifications of crops compared to traditional breeding methods and have potential for meeting future agricultural demands.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms for those who already suffer from conditions like anxiety and depression.
The plant hormone abscisic acid (ABA) plays a key role in mediating plant adaptation to stress. It induces stomatal closure to reduce water loss during drought, inhibits cell growth and seed germination to enforce seed dormancy, and promotes bud dormancy and the development of bud scales during winter. ABA is produced in response to decreased soil water availability and other stressors, then translocates to leaves and buds to trigger adaptive responses that prevent water loss and allow plants to survive potentially harmful conditions like drought and winter.
The plant hormone abscisic acid (ABA) mediates plant adaptation to stress by inducing stomatal closure to reduce water loss, inhibiting cell growth and seed germination to promote dormancy, and regulating bud formation and abscission. ABA is produced in response to stresses like drought, cold temperatures, and soil compaction and translocates from roots to leaves to trigger closing of stomata and reduce transpiration. It plays important roles in enforcing bud and seed dormancy, inhibiting seedling growth, and preventing premature sprouting or germination until conditions are suitable.
Abscission is the process by which plant organs such as leaves, flowers, and fruits become detached from the plant in a controlled manner. It occurs through the formation of an abscission zone, a layer of weak-walled cells located at the base of the petiole or other structure. Abscission is controlled by the plant hormones auxin and ethylene, with decreasing auxin and increasing ethylene levels initiating cell wall degradation in the abscission zone. This allows separation of plant organs through a combination of enzymatic breakdown and mechanical forces. Abscission aids in shedding organs no longer needed by the plant and occurs in response to environmental and developmental signals.
Abscisic acid (ABA) is a plant hormone that plays a key role in mediating plant responses to stress. It induces stomatal closure to reduce water loss during drought, inhibits cell growth to induce seed and bud dormancy over winter, and promotes the development of protective bud scales. ABA is produced in response to stresses like drought, cold temperatures, and soil compaction and translocates to leaves and buds to trigger adaptive responses that allow plants to survive adverse conditions.
Bio chemistry of plant & insect hormonesPoojaHorti
Plant and insect hormones play important roles in growth and development. The major plant hormones are auxins, gibberellins, cytokinins, ethylene, and abscisic acid. Auxins promote cell elongation, root initiation, apical dominance, and other processes. Gibberellins stimulate stem growth and flowering. Cytokinins induce cell division and inhibit senescence. Ethylene causes fruit ripening and leaf abscission. Abscisic acid induces seed dormancy and stomatal closure. In insects, prothoracicotropic hormone triggers ecdysone secretion, which controls molting along with juvenile hormone.
Auxins and gibberellins would enhance stem elongation and fruit growth.
- Auxins promote cell elongation and division, resulting in stem elongation.
- Gibberellins also promote stem elongation by overcoming the inhibitory effect of other hormones.
- Ethylene and cytokinins generally do not directly promote stem or fruit growth. Cytokinins promote cell division but not elongation. Ethylene inhibits stem elongation.
- Abscisic acid and phytochrome are not directly involved in promoting stem or fruit growth. Abscisic acid inhibits growth and phytochrome regulates photoperiodism.
Therefore, the correct answer is A - Auxins and gibberellins.
The document discusses the growth and development of different plant structures including leaves, roots, stems, and tubers. It describes the functions and mechanisms of growth for each structure. The mechanisms of growth discussed include seed germination, photosynthesis, and plant hormones. The major plant hormones and their functions are also summarized.
This document provides an overview of a seminar on plant hormones and growth regulators. It discusses the five major plant hormones: auxins, cytokinins, gibberellins, abscisic acid, and ethylene. For each hormone, it describes their classification, discovery, roles in plant growth and development processes like cell division, fruit ripening, dormancy, and responses to environmental stresses. The document aims to inform attendees about the key functions and effects of different plant hormones.
Plant growth and development occurs through various processes. Leaves grow from leaf primordia in the shoot apical meristem and develop through unfolding of the leaf blade. Roots grow from the root apical meristem through cell division and differentiation. Stems provide support and transport of water and nutrients through primary growth in length and secondary growth in thickness. Tubers are storage and reproductive structures that develop from thickened stems or roots. Plant growth is driven by mechanisms like seed germination, photosynthesis, and plant hormones that regulate cell division and expansion.
Auxins are a group of plant hormones that play a key role in plant growth and development. They stimulate stem and root elongation, promote apical dominance, influence tissue differentiation and organ formation, and are involved in phototropism and gravitropism. Auxins move from areas of high concentration to low concentration through active transport processes. An increase in auxin concentration on one side of a plant organ causes asymmetric growth and bending towards lower auxin levels in response to stimuli like light and gravity. Many synthetic auxins are used commercially in horticulture to promote rooting of cuttings, prevent fruit drop, induce parthenocarpy, and for selective weed control.
1. Plant hormones regulate many growth and developmental processes in plants such as stem elongation, root growth, flower development, fruit ripening, and leaf senescence.
2. There are five major classes of plant hormones: auxins, gibberellins, cytokinins, ethylene, and abscisic acid. Each has different functions in promoting or inhibiting growth.
3. Horticulturists apply plant growth regulators, which are synthetic versions of plant hormones, to regulate aspects of plant growth like promoting rooting in cuttings or preventing stem elongation. Maintaining adequate carbon dioxide levels is also important for optimal plant growth.
Plant growth regulators are molecules that influence plant development and include natural and synthetic hormones. Natural hormones include auxins, gibberellins, ethylene, abscisic acid, and cytokinins. They control various growth processes like elongation, flowering, fruit ripening, and responses to stress. Common synthetic regulators are NAA and 2,4-D which are used as rooting agents and herbicides respectively to induce uncontrolled growth. Both natural and synthetic regulators have various agricultural and horticultural applications.
Plant hormones play an important role in plant tissue culture. Abscisic acid helps with somatic embryogenesis during maturation and germination. Cytokinins like zeatin stimulate cell division and shoot bud formation, while inhibiting embryogenesis and root induction. Auxins like IAA induce callus formation from explants and cause root and shoot morphogenesis. Gibberellins like GA3 and GA4+7 induce organogenesis and adventitious root formation. Together, the precise balance and combination of these hormones allows plant tissue culture to generate plants from single cells under the right conditions.
This document is a project write-up on plant growth hormones submitted by Abhinav Baranwal to Dr. Gurminder Kaur. It discusses the five major classes of plant hormones (auxins, gibberellins, cytokinins, abscisic acid, and ethylene) and provides details on their discovery, chemical nature, physiological functions, and agricultural uses. The write-up acknowledges those who provided guidance and assistance during the project.
This document discusses the plant hormones abscisic acid and ethylene. It defines plant hormones as internally secreted chemicals that regulate plant growth. Abscisic acid is a growth inhibitor that induces bud and seed dormancy, stops cambium activity, promotes abscission, and stimulates leaf senescence. Ethylene is a gaseous hormone that stimulates transverse growth but inhibits longitudinal growth. It hastens senescence and abscission, breaks dormancy, aids fruit ripening, and influences flowering and sex expression. Both hormones help plants adapt and respond to environmental stresses.
Moisture stress affects many aspects of plant growth and development including water relations, photosynthesis, respiration, anatomy, hormones, metabolism, nutrition, growth, development, reproduction and yield. Excess water can also be harmful by causing waterlogging and inhibiting aeration of soils. Crops develop various adaptations to moisture stress including avoidance through traits like deep roots or tolerance through osmotic adjustment. The ideal strategy is to avoid both moisture stress and excess water conditions.
Plant growth occurs through mitosis and cell division in the shoot apex and root meristems, which are zones of undifferentiated cells that allow indeterminate growth. The plant hormone auxin controls cell elongation and growth in the shoot apex in response to light cues. Auxin concentration gradients are established through efflux pumps that move auxin out of illuminated cells into shaded cells, causing the shoot to bend or curve towards the light source in a process called phototropism.
Plant hormones (auxins, gibberellins, cytokinins, ethylene, abscisic acid) act as chemical messengers that control many plant growth and developmental processes. They are produced in one part of the plant and transported to other parts to initiate responses. Plant growth regulators include both natural and synthetic chemicals that influence plant growth and development when applied. The five major classes of natural plant hormones each have distinct functions such as cell elongation, dormancy, senescence and stress responses.
The document appears to be a chart showing the budget breakdown for various construction projects at Mwenge Catholic University over 5 years. It includes line items for a new construction, campus pathways, parking, and buildings such as hostels, laboratories, administration blocks, lecture rooms, libraries, and staff housing. The numbers in the columns possibly represent budget amounts in local currency for each year.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise has also been shown to increase gray matter volume in the brain and reduce risks for conditions like Alzheimer's and dementia.
This document provides an overview of the Mgori Forest community-based natural resource management program in Singida District, Tanzania. It describes the biophysical characteristics of the Mgori Forest and the establishment of the community management program in 1995 with support from external donors and consultants. The program has been largely successful, with forest regeneration occurring and returns of wildlife. However, some ongoing issues include lack of formal approval of village bylaws, boundary disputes with neighboring districts, and lack of resources for forest patrols and protection activities. Effective governance, addressing economic needs, and sustainable biophysical management are keys to the long-term success of the program.
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ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
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Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
বাংলাদেশ অর্থনৈতিক সমীক্ষা (Economic Review) ২০২৪ UJS App.pdf
Plants hormoness
1. Table of Contents
Introduction.......................................................................................................................................2
ABSCISIC............................................................................................................................................2
Functions of abscisic hormone in plant.............................................................................................2
Agricultural uses of abscisic hormone ..............................................................................................3
Cytokinins..........................................................................................................................................3
Functions of abscisic hormone in plant.............................................................................................4
Uses of cytokinins inAgriculture and Horticulture.............................................................................4
AUXINS..............................................................................................................................................5
Functions of abscisic hormone in plant.............................................................................................5
Uses of Auxins in Agriculture and Horticulture..................................................................................6
Gibberellins........................................................................................................................................7
Functions of Gibberellins.................................................................................................................8
Agricultural Applications of Gibberellins...........................................................................................9
ETHYLENE ........................................................................................................................................10
Functions of Ethylene in plant........................................................................................................10
Agricultural application of Ethylene ...............................................................................................10
Conclusion .......................................................................................................................................11
2. Introduction
Plant hormones are signal molecules produced within the plant, and occur in extremely low
concentrations. Hormones regulate cellular processes in targeted cells locally and, moved to other
locations, in other functional parts of the plant. Hormones also determine the formation of flowers,
stems, leaves, the shedding of leaves, and the development and ripening of fruit. Plants, unlike
animals, lack glands that produce and secrete hormones. Instead, each cell is capable of producing
hormones. Plant hormones shape the plant, affecting seed growth, time of flowering, the sex of
flowers, senescence of leaves, and fruits. They affect which tissues grow upward and which grow
downward, leaf formation and stem growth, fruit development and ripening, plant longevity, and
even plant death. Hormones are vital to plant growth, and, lacking them, plants would be mostly a
mass of undifferentiated cells. So they are also known as growth factors or growth hormones
ABSCISIC
Abscisic acid is a single compound. It was called abscisic II originally because it was thought to
play a major role in abscission of fruits. It major role in bud dormancy. (Johnson, 2009)
Functions of abscisic hormone in plant
Closing of stomata
Most the water taken up by a plant is lost in transpiration. Most of this leaves the plant through the pores
called stomata in the leaf. Each stoma is flanked by a pair of guard cells. When the guard cells are turgid,
the stoma is open. When turgor is lost, the stoma closes. In angiosperms and gymnosperms ABA is the
hormone that triggers closing of the stomata when soil water is insufficient to keep up with transpiration.
Protecting cells from dehydration
ABA signalling turns on the expression of genes encoding proteins that protect cells in seeds as well as in
vegetative tissues from damage when they become dehydrated.
Root growth
ABA can stimulate root growth in plants that need to increase their ability to extract water from the soil.
Bud dormancy
ABA mediates the conversion of the apical meristem into a dormant bud. The newly developing leaves
growing above the meristem become converted into stiff bud scales that wrap the meristem closely and will
protect it from mechanical damage and drying out during the winter.
3. Seed maturation and dormancy
Seeds are not only important agents of reproduction and dispersal, but they are also essential to the survival
of annual and biennial plants. These angiosperms die after flowering and seed formation is complete. ABA
is essential for seed maturation and also enforces a period of seed dormancy.
Abscission
ABA also promotes abscission of leaves and fruits (in contrast to auxin, which inhibits abscission). It is, in
fact, this action that gave rise to the name abscisic acid. The dropping of leaves in the autumn is a vital
response to the onset of winter when ground water is frozen and thus cannot support transpiration and snow
load would threaten to break any branches still in leaf.
Apical dominance
ABA moving up from the roots to the stem synergizes with auxin moving down from the apical meristem
to the stem in suppressing the development of lateral buds. The result is inhibition of branching or apical
dominance.
Agricultural uses of abscisic hormone
Abscisic Acid Application Enhances Drought Stress Tolerance in Bedding Plants.
Drought stress is a major cause of postproduction decline in bedding plants. The plant hormone
abscisic acid (ABA) regulates drought stress responses by mediating stomatal closure, thereby
reducing transpirational water loss.
Cytokinins
Cytokinins or CKs are a group of chemicals that influence cell division and shoot formation. They
are called kinins since after isolated from yeast cells. They also help delay senescence of tissues,
are responsible for mediating auxin transport throughout the plant, and affect internodal length and
leaf growth. They have a highly synergistic effect in concert with auxins, and the ratios of these
two groups of plant hormones affect most major growth periods during a plant's lifetime.
Cytokinins counter the apical dominance induced by auxins; they in conjunction with ethylene
promote abscission of leaves, flower parts, and fruits. (Tortora and, Derrickson, 2009)
4. Functions of abscisic hormone in plant
The correlation of auxins and cytokinins in the plants is a constant. Because cytokinin promotes
plant cell division and growth, produce farmers use it to increase crops.
The cytokinin stimulate growth, a hormone that promotes cytokinesis (cell division).Cytokinins
are most abundant in growing tissues, such as roots, embryos, and fruits, where cell division is
occurring.
Cytokinins are known to delay senescence in leaf tissues, promote mitosis, and stimulate
differentiation of the meristem in shoots and roots. Many effects on plant development are under
the influence of cytokinins,
Conjunction with auxin or another hormone. For example, apical dominance seems to result from
a balance between auxins that inhibit lateral buds and cytokinins that promote bushier growth.
Uses of cytokinins in Agriculture and Horticulture
Cytokinins have recently been found to play a role in plant pathogenesis. For example, cytokinins
have been described to induce resistance against Pseudomonas syringae in Arabidopsis thaliana.
Also in context of biological control of plant diseases cytokinins seem to have potential functions.
Production of cytokinins by Pseudomonas fluorescens G20-18 has been identified as a key
determinant to efficiently control the infection of A. thaliana with P. syringae
Plant hormones cytokinins regulate various aspects of plant growth and development. For their
positive effects on branching, delaying of senescence, nutrient remobilisation, flower and seed set
control they became interesting substances in search for potential agrochemicals.
5. AUXINS
Auxins are a family of hormones found in plants. Auxins are mostly made in the tips of the shoots and
roots, and can diffuse to other parts of the shoots or roots. They change the rate of elongation in plant cells,
controlling how long they become. Shoots and roots respond differently to high concentrations of auxins:
(Campbell, 2008)
Functions of abscisic hormone in plant
Phototropism
In a shoot, the shaded side contains more auxin. This means that the shaded side grows longer, causing the
shoot to bend towards the light.
The diagram shows the typical results shown by oat seedlings grown in a box with a light from
one side
Gravitropisms
Auxins are also involved in gravitropisms. In a root placed horizontally, the bottom side contains more
auxin than the top side. This makes the bottom side grow less than the top side, causing the root to bend in
the direction of the force of gravity.
In a shootplacedhorizontally, the bottom side contains more auxin than the top side. This makesthe bottom
side grow more than the top side, causing the shoot to bend and grow against the force of gravity.
6. Uses of Auxins in Agriculture and Horticulture
Apical Dominance:
The auxins greatly influence the development of plant form and structure. It has long been known that
while the mainshootof a plantis growing,itslateral budsare inhibited.If,however,the budat the apex
is cut off, the lateral buds begin to develop.
Meristematic Activity
Auxinaffectsthe meristematicactivityof cellsotherthanthose involvedintumorand callusproduction.
Auxinproducedinthe apical budstimulatesandregulatesthe activityof the cambiuminwoodyplants.It
seemsprobablethatthe resumptionof cambialgrowthinthe springisduetoauxinproducedbythe buds
in this season.
Rooting
Propagation of plants by vegetative means is quite commonly practiced in horticulture. Several
experiments performed on a great variety of plants showed that auxin applications are generally
beneficial in bringing about the rooting of cuttings. It is extremely useful to the horticulturists, for by
meansof ita greatmany geneticallyidentical plantsmaybe made froma single individual,andadesired
genetic pattern
Parthenocarpic or Seedless Fruits
Another property of auxins that has grown to economic importance is their ability, when applied to the
flowers of certain species, to initiate development of fruit without pollination.
Prevention of Premature Fall of Fruits
In growersof citrus,applesandpearsuse large amountsof auxinsforthe preventionof premature fall of
fruits.
Sex Expression
The spray of auxins increases the number of female flowers in cucurbits. In maize, application of
Nepthalene Acetic Acid during the period of inflorescence differen-tiation can induce formation of
hermaphrodite or female flowers in a male inflorescence. Thus auxins induce femaleness in plants.
Control of Lodging
7. In some plants when the crop is ripe and there is heavy rain accompanied by strong winds, the plants
bendas a resultof whichthe ear (inflorescence) getssubmergedinwateranddecays.If a dilute solution
of any auxin is sprayed upon young plants, the possibility of bending of plants is reduced as the stem
becomes stronger by the application of auxins.
Gibberellins
include a large range of chemicals that are produced naturally within plants and by fungi. Chemical
produced by a fungus called Gibberella fujikuroi that produced abnormal growth in rice plants.
Gibberellins are important in seed germination, affecting enzyme production that mobilizes food
production used for growth of new cells. This is done by modulating chromosomal transcription.
In grain seeds, a layer of cells called the aleurone layer wraps around the endosperm tissue.
Absorption of water by the seed causes production of GA. The GA is transported to the aleurone
layer, which responds by producing enzymes that break down stored food reserves within the
endosperm, which are utilized by the growing seedling. GAs produce bolting of rosette-forming
plants, increasing internodal length. They promote flowering, cellular division, and in seeds
growth after germination. Gibberellins also reverse the inhibition of shoot growth and dormancy
induced by ABA. The gibberellins are weakly acidic phytohormones which help in longitudinal growth
of stem. (H.Edward, 2005)
Avena test (a) A piece of mica inserted on the shaded side prevented curvature of the coleoptile, (b) but not
when it was inserted on the illuminated side, (c) when the tip was removed (d) but was put back with a
block of gelatine, (e) normal phototropic curvature occured
8. Functions of Gibberellins
Stem elongation
Gibberellins cause stem elongation and leaf expansion. It is believed that certain types of
dwarfness are due to gibberellins deficiency. But it has no effect on roots.
Bolting
Gibberellins induce stem elongation in rosette plants. Cabbage is a rosette plant with profuse leaf
growth and retarded intermodal length. Just prior to flowering, internodes elongate enormously.
This is called bolting. Bolting needs either long days or cold nights. When a cabbage head is kept
under warm nights, it retains its rosette habit. Bolting can be induced artificially by the application
of gibberellins under normal conditions.
(Johnson, 2009)
Seed Germination
Gibberellins promote seed germination in lettuce, cereals.
Breaking of seed dormancy
Gibberellins break dormancy of buds and tubers. But in root tubers it inhibits the development of
the root tuber.
9. Parthenocarpy
Gibberellins cause parthenocarpy in apple and pear.
Increasing Fruit Size
Gibberellins along with auxin control the growth and development of fruits.
Flowering and sex expression
Gibberellins control flowering in long day plants. Gibberellins promote the production of male
flowers, either in place of female flowers in monoecious plants or in genetically female plants such
as cucurbits.
Agricultural Applications of Gibberellins
Fruit growth and parthenocarpy
Increased yield (larger size) and better shape of grapes is obtained by treating the fruit bunches
with GA. It induces parthenocarpy in apples, pears, tomatoes and cucumbers.
Delayed ripening
Gibberellins delay fruit maturity and senescence in lemons, oranges and cherries. This helps in
storing the fruits. Used in long distance trade of fruits.
Flowering
Gibberellins help in the flowering of many long day plants.
Breaking of Dormancy
Gibberellins treatment helps in breaking dormancy in “seed potatoes” resulting in uniform crop
emergence.
Malting
Gibberellins have been used to increase synthesis of various hydrolytic enzymes such as amylase,
ribonuclease and protease in aleurone cells of barley.
10. ETHYLENE
Ethylene is a plant hormone that differs from other plant hormones in being a gas. As they approach
maturity, many fruits (example. Apples, oranges, avocados) release ethylene. Ethylene then promotes the
ripening of the fruit. The presence of ethylene is detected by transmembrane receptors in the endoplasmic
reticulum (ER) of the cells. Binding of ethylene to these receptors unleashes a signalling cascade that leads
to activation of transcription factors and the turning on of gene transcription.
Functions of Ethylene in plant
Ethylene affects fruit-ripening: Normally, when the seeds are mature, ethylene production
increases and builds-up within the fruit, resulting in a climacteric event just before seed
dispersal.
Ethylene inhibits elongation of stem and roots and causes swelling of plant parts.
Ethylene retards flowering in most plants but also increases flowering in some plants.
Treatment of plants with ethylene increases the number of female flowers and fruits in
cucumber.
Ethylene is considered as responsible for positive geotropic bending of roots.
Ethylene inhibits the growth of lateral buds and thus causes apical dominance.
Ethylene stimulates the growth of fruits in some plants. It is considered responsible for the
changes that occur during the ripening of fruits.
Ethylene stimulates rooting of cuttings, initiation of lateral roots and growth of root hair.
Ethylene promotes the yellowing and senescence of leaves. It also induces flower fading
in pollinated orchids. (Srivastava, 2002)
Agricultural application of Ethylene
The plant hormone ethylene promotes ripening, as seen in the ripening of dates. Ethylene is widely used in
agriculture. Commercial fruit growers control the timing of fruit ripening with application of the gas.
Horticulturalists inhibit leaf dropping in ornamental plants by removing ethylene from greenhouses using
fans and ventilation.
11. Conclusion
There exists a certain elegance by which the hormones counteract each other, regulate each other,
and create completely unique and unexpected effects in tandem.The balance of auxin and
cytokinin, not either hormone in isolation, allow for calluses to differentiate, while abscisic acid
and gibberelins struggle against each other in regulation of seed dormancy.
And, thanks to the ability of artificial synthesis and extraction processes, agricultural and
ornamental plant growth can be made to change to whatever needs mankind demands of it.In some
cases, as it is in abscisic acid, humanity can lay claim to having already synthesized a chemical
superior to what can be obtained in nature, prolonging the natural protective effect.
Those people can feed themselves, clothe themselves, and pull up their economic status through
agriculture far more easily, and perhaps, far more reliably, despite wind and cold.And for much of
the same reasons, big business will find profits lining their pockets like never yet, by making larger
operations ever more efficient, ever more yielding, ever less labour intensive, and ever more
diverse in its ability to use land.
12. References
Campbell,N.A.(2008). Biology . UnitedStatesof America:PearsonEducation.
Elliot,T.(1979). a brief introduction to plant biology. New York:Wiley.
H.Edward.(2005). The physiology of flowering plants. London: Cambridge UniversityPress.
Johnson,R.(2009). Biology . USA.
Srivastava,L.M. (2002). Plantgrowthand development. USA:AcademicPress.
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https://pages.wustl.edu/ipgsa/ethylene.
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