Plant Growth Hormones

Power Point Presentation

1. S 1 Presented By : Mohsin Shad ( 2013-BC-005) Presented To : Miss Rahat Naseer

2. Plant Growth H ormones 2

3. Plant Hormones Chemicals that regulate plant growth S ignal molecules produced within the plant, and occur in extremely low concentrations. C hemical messengers that affect a plant's ability to respond to its environment . 3

4. General Plant H ormones There are some plant hormone which are described below: Auxins Gibberellins Cytokinins  Ethylene Abscisic A cid 4

5. Auxins F irst of the major plant hormones to be discovered. Indole-3-acetic acid (IAA) is the most common, naturally-occurring, plant hormone of the auxin class. 5

6. Functions of Auxins Frits Went (1926) determined auxin enhanced cell elongation and Stem elongation . 6

7. Functions of Auxins Auxins also influences root formations. R esponsible for apical dominance and phototropism. Promotes xylem differentiation. Retards leaf abscission. Promotes fruit growth. 7

8. Gibberellin Produce i n young, developing shoots and seeds Gibberellin have some known actions in the development of: Cell division Cell elongation Stimulate seed germination Stimulate flowering Stimulate fruit development 8

9. Commercial use of GA Thompson seedless grapes ( Vitis ( Vitaceae family) Without GA With GA Larger fruits that are easier to clean are attractive in markets 9

10. Cytokinins Produce in primarily root tips Cytokinins have some known actions in the process of: Cell division (cytokinesis) Tissue culture Delay leaf senescence 10

11. Cytokinin delays leaf senescence (ageing and reabsorption of aged organs) Transgenic Untreated Genetic modification to increase Cytokinin biosynthesis Nicotiana ( Solanaceae family ) 11

12. Ethylene Produce in most tissues under stress, senescence , or ripening Ethylene have s ome known actions in the development of: Fruit ripening Leaf and flower senescence Leaf and fruit abscission (controlled separation of plant part from the main body) Floral sex determination in monoecious species, promote female 12

13. Experimenting with plant response to ethylene commercial uses Mutated ethylene receptor Normal ethylene receptor levels Both are 100 days after picking Lycopersicon ( Solanaceae family) 13

14. Abscisic Acid (ABA) Abscisic Acid Produce in: Mature leaves, especially under stress Roots , then transported to shoots Abscisic Acid have s ome known actions that is: Stress response Stimulate stomatal closure Inhibit premature germination of seeds Embryogenesis Seed dormancy maintenance 14

15. ABA induces stomatal closure a simplified diagram Solutes ( e.g. potassium and chloride ions) accumulate in guard cells causing water to accumulate in guard cells, making them turgid ABA is one signal that causes guard cells to release solutes and thus release water, making them flaccid and closing the stoma (pore) between them Guard cell response to ABA is one topic of research in the Outlaw lab at FSU 15

16. Any Question ? 16 For Listening Our Presentation