Plant Hormone Signal transduction pathway 植物激素信号转导通路.ppt

1、Plant Hormone Signal transduction pathway,Talk Outline,General introduction to cell signaling transduction pathways in plant. Different plant hormones and their physiological function in plants. Comparison between plant hormones and animal hormones action. Ways or approaches in studying plant hormon

2、e signaling transduction pathways. Molecular mechanism of various plant hormone signal transduction pathways (a) ubiquitin-dependent protein degradation (negative regulator) (b) tow component system (phospho-relay).,6. Manipulation of plant growth and development with knowledge from plant hormone si

3、gnal transduction pathway. ex. Second green revolution.,Analogy view of cell signaling transduction pathway,Input (command) Keyboard Signal perception Endogenous: phytohormone Exogenous: environmental cue,CPU (Central Processing Unit) Chip Signal Transduction Network Compiling, Integration, processi

4、ng,Output (performance) Printer Signal Response Morphogenesis change, Growth development differentiation,Various signaling transduction pathways in plants,Calcium (Ca+2) signaling (regulatory network) Lipid signaling transduction pathway Reactive oxygen species (ROS) signaling Nitric oxide (NO) sign

5、aling transduction pathway Sugar sensing responsive pathway Wounding-signal transduction pathway (plant-pathogen interaction) Light signaling responsive pathway Biological oclock (circadian rhythm) regulatory pathway,Development regulatory pathway e. g. flowering (autonomous), lead, root, trichome f

6、ormation root apical meristem (RAM) shoot apical meristem (SAM) formation polarity and cell cytoskeleton rearrangement Specific cell fate determination and differentiation (Xylem and phloem specification, root organization (patterning) Abiotic stress signaling pathways (salt, drought, heat, cold, me

7、tal, vernalization etc.) Plant hormone signaling transduction (auxin, ethylene, cytokinin, gibberellin, abscisic acid, brasinosteroid, jasmonic acid etc.),Definition of plant hormone,The word hormone is derived from the Greek verb meaning to excite. hormones are organic substances synthesized in one

8、 tissue and transported out where their presence results in physiological responses ( not always true; may act at or close to synthesis site). They are required in minute amounts (10-6 to 10 -8M). 3.Each hormone may result in multiple effects - the particular effect depending on a number of factors:

9、 (a) the presence of other hormones and the presence of activator molecules ( calcium, sugars) (b) the amount of the hormone (dosage or concentration) (c) the sensitivity of that tissue to the hormone. (d) the condition of the plant itself is critical: what is the condition of the plant? its age?,Si

10、te of action x developmental stage x concentration of hormone? Crosstalk and specificity?,Chemical Structures of the Plant Hormones,plant hormones synthesis sites and their major functions,Effects of plant hormones on plant growth and development,Embryogenesis,(Cell division, expansion, differentiat

11、ion and cell death),Senescence,What is the difference between plant hormones and animal hormones?,Main approaches used to study plant hormone perception, signal transduction biosynthesis and responses Molecular genetics approach hormone biosynthetic mutants vs. hormone insensitive mutants,2. Biochem

12、istry approach hormone binding protein (photo-affinity probe, affinity chromatography, immunopurification) 3. Inhibitor approach kinase/phosphatase, G-protein, PKC etc inhibitors,Science, 2001,Dissect plant hormone signal transduction pathways by molecular genetic analysis,Chronological events and p

13、ersons involved in identification of different hormone receptors,2007 (CHLH, GCR2),Summary of molecular components involved in plant hormone signaling transduction,Auxin: TIR1: F-box protein (Ubiquitin conjugated ligase) PIN1 (pin-formed 1) Aux/IAA repressor Ethylene: histidine kinase Raf-like kinas

14、e CTR1 Mitogen activated protein kinase cascade Cytokinin: phosphorelay (two-component system) 4.Gibberellin: G protein and DELLA protein hexosamine (NAcGlu) 5.Abscisic acid: PP2C protein, SnRK protein kinase Farnesylation Brasinosteroid: BRI1 (LRR-RLK),An overview of the ubiquitination process in p

15、lants,Annals of Botany 99: 787-822 (2007),E1; UBA, ubiquitin activating enzyme E2: UBC, ubiquitin conjugatingenzyme E3: ubiquitin protein ligase RBX: ring-box protein CUL: cullin CRL:cullin ring ligase HECT: homologous to E6-AP COOH terminus RING: really interesting new gene protein domain SCF: SKP1

16、-Cullin-F-box SKP: S phase kinase associated protein F-box: SKP/ASK interaction motif in cyclin F,Biological significance of ubiquitin/proteosome system (UPS) in plants,UPS was involved in different processes of plant life, including organ initiation and embryogenesis patterning, light signalling ,

17、circadian clock regulation ,hormone production, perception and signal transduction, and in plant defence. 2. The covalent attachment of ubiquitin to a substrate protein changes its fate. Notably, proteins typically tagged with a lysine48-linked polyubiquitin chain become substrates for degradation b

18、y the 26S proteasome. Over 6 % (1,500 genes) of the predicted arabidopsis genome encodes proteins involved in the UPS, and analyses of other plant genomes demonstrate a similar abundance of UPS-related genes. E1 (1); E2 (1); UEV (8); E3 (mast abundant): HECT (7); Ring (450); U-domain (61); cullin (1

19、1); F-box (700) BTB (80),Comparison between auxin and gibberellin signaling pathway,Development 133, 1857-1869 (2006),Crystal structure of the TIR1ASK1 complex with auxin and theIAA7 degron peptide,auxin function as a molecular glue to enhanceTIR1substrate interactions,Nature 446, 2007,Phenotypes as

20、sociated with the auxin and gibberellin receptor mutants,Development 133, 1857-1869 (2006),Brassinosteroid signaling pathway,Development 133, 1857-1869 (2006),Phenotypes associated with the brassinosteroid, ethylene, cytokinin and abscisic acid receptor mutants,Development 133, 1857-1869 (2006),Abscisic acid receptors: multiple signal-perception sites,Annals of Botany 17, 2007,FCA is a nuclear receptor for ABA controli