植物逆境信息傳遞研究進展

1、 Stress Signaling in Plants 賈文鎖賈文鎖 中國農(nóng)業(yè)大學中國農(nóng)業(yè)大學一 “感知感知”和和“反應反應” 生物生存和發(fā)展的基礎生物生存和發(fā)展的基礎 敏感植物敏感植物 一般植物一般植物Rain,Wind, and Touch-Induced Expression of Calmodulin and Calmodulin-Related Genes in ArabidopsisCell 60,357-364,1990二“刺激刺激/逆境逆境”“反應反應/應答應答”1. 1.形態(tài)、解剖形態(tài)、解剖Cluster Roots2. 2.整體生理整體生理生命周期短命菊3.細胞生理及生化(

2、1) 解毒機制(2)自由基清除(3)區(qū)隔化機制(4)代謝調(diào)控(5)滲透調(diào)節(jié)(6)保水機制(7)結構避損機制(8)修復機制滲透調(diào)節(jié)滲透調(diào)節(jié)脯氨酸脯氨酸甜菜堿甜菜堿山梨醇山梨醇海藻糖海藻糖保護酶系統(tǒng)與自由基清楚劑保護酶系統(tǒng)與自由基清楚劑游離的帶有不成對電子的分子、原子或離子游離的帶有不成對電子的分子、原子或離子區(qū)隔化機制區(qū)隔化機制結構避損機制結構避損機制功能蛋白功能蛋白 代謝調(diào)控蛋白 （滲透調(diào)控系統(tǒng)，保護酶）Lea 蛋白（Late-Embryogenesis-Abundant Protein）通道蛋白：離子通道，水通道熱擊蛋白：親水，保護酶活損傷修復蛋白調(diào)節(jié)蛋白調(diào)節(jié)蛋白信號蛋白轉錄因子基因 功能蛋

3、白基因 調(diào)節(jié)蛋白基因應答反應與傷害反應三 信號系統(tǒng)與信號組分 Cellular Singling System ?細胞信號系統(tǒng)細胞信號系統(tǒng) 1 Receptor /Sensor 2. Second Messenger 3. Protein Kinase 4. Protein Phosphatase 5. G-protein 6. Transcription Factor 7. Ubiquitination 8. Methylation Signal Components(1) Receptor /Sensor?Receptor tyrosine kinase 細胞內(nèi)受體Examples of

4、Phytohormone Recepor and Signal TransductionABA Receptor BRI1 is a membrane-associated receptor that cycles between the plasma membrane and endosomal compartments. The extracellular leucine-rich repeat domain binds brassinosteroids and transduces the signal through an intracellular kinase domain. GT

5、G1 and GTG2 are GPCR-type G proteins that bind abscisic acid. They have inherent GTPase activity but also interact with the only canonical G subunit in Arabidopsis. PYR1/RCAR1 is a soluble ABA receptor that represses PP2C phosphatases in the presence of ABA. The cytokinin receptors CRE1, AHK2 and AH

6、K3 are plasma-membrane-associated and perceive cytokinin through their extracellular domains. Cytokinin binding triggers a phosphorylation cascade that is ultimately transmitted to response regulators in the nucleus. Like the cytokinin receptors, the known ethylene receptors are two-component regula

7、tors. All five receptors are active in the endoplasmic reticulum and transmit their signal through a common downstream component called CTR1. TIR1 and COI1 are F-box proteins that are integral components of SCF-type E3 ligases and recognize the plant hormones auxin and jasmonic acid respectively. GI

8、D1 is a nuclear-localized receptor for gibberellins. Gibberellin binding toGID1 results in the enhanced degradation DELLA proteins 自由基信號轉導(3) Reversible Protein Phosphorylaton (4) Transcription Factors 泛素泛素(ubiquitin)(ubiquitin)是一種存在于大多數(shù)真核細胞中的小蛋白。它的主要功能是標記需要分解掉的蛋白質(zhì)，使其被水解。當附有泛素的蛋白質(zhì)移動到桶狀的蛋白酶的時候，蛋白酶就會將

9、該蛋白質(zhì)水解。也可能被轉移到細胞或細胞外的特定部位，也有可能導致靶蛋白的功能發(fā)生變化。泛素76個氨基酸組成，分子量大約8.5 KDUbiquitination 四細胞逆境信息傳遞細胞逆境信息傳遞 舉例介紹舉例介紹鹽脅迫和營養(yǎng)脅迫離子通道的調(diào)節(jié)Figure 12. Freezing and Drought Tolerance of the 35S:DREB1Ab and 35S:DREB1Ac Transgenic Plants.Control, 3-week-old plants growing under normal conditions; freezing stress, plants

10、exposed to a temperature of -6C for 2 days and returned to 22C for 5 days; drought stress, water withheld from plants for 2 weeks. Percentages of surviving plants and numbers of surviving plants per total number of tested plants are indicated under the photographs. wt, wild type. History of Abscisic

11、 Acid (ABA) In 1963, abscisic acid was first identified and characterized by Frederick Addicott and his associates. They were studying compounds responsible for the abscission of fruits (cotton). Two compounds were isolated and called abscisin I and abscisin II. Abscisin II is presently called absci

12、sic acid (ABA)(Addicot, 1963). Two other groups at about the same time discovered the same compound. One group headed by Philip Wareing was studying bud dormancy in woody plants. The other group led by Van Steveninck was studying abscission of flowers and fruits from lupine. Plant physiologists agre

13、ed to call the compound abscisic acid (Salisbury and Ross, 1992). Signaling From Water Stress Sensing to ABA Accumulation 五五 系統(tǒng)逆境信息傳遞系統(tǒng)逆境信息傳遞Systematic Signaling in Plantsor long-distance signaling, or intercellular signalingRoot To Shoot Signaling Under Water Deficit Condition pH SignalingImage 2.

14、Psedu Color Ratio-images of Image 2. Psedu Color Ratio-images of pH indicator BCECF in sunflower sunflower stem and leaf vascular systemstem and leaf vascular system pH indicator BCECF was loaded into the vascular system of an individual sunflower plant and images were acquired as described in Mater

15、ial and Method. A, vascular system at stem base; B, vascular system at midrib of leaf blade. Image 3. Psedu Color Ratio-images Image 3. Psedu Color Ratio-images Showing the Effect of transpiration rate Showing the Effect of transpiration rate on leaf apoplastic pH of Commelina on leaf apoplastic pH

16、of Commelina communis L. communis L. pH indicator NERF was first loaded into intact plant through root system, then the plants were allowed to transpire for 1 h under either 35% or 85% humidity, following which fluorescence images were acquired as described in Material and Method . A and B, transpir

17、ation at 35% humidity; C and D, transpiration at 85 % humidity.Image 3. Psedu Color Ratio-images Showing the Effect of transpiration Image 3. Psedu Color Ratio-images Showing the Effect of transpiration rate on leaf apoplastic pH of Commelina communis L. rate on leaf apoplastic pH of Commelina commu

18、nis L. pH indicator NERF was first loaded into intact plant through root system, then the plants were allowed to transpire for 1 h under either 35% or 85% humidity, following which fluorescence images were acquired as described in Material and Method . A and B, transpiration at 35% humidity; C and D

19、, transpiration at 85 % humidity.干旱條件下ABA可以作為長距離傳遞信號使植物產(chǎn)生系統(tǒng)抗逆性Systematic Signaling of Large Molecular SignalsFig. 3. New model for the photoperiod response in plants. (A) The picture on the left represents the currently accepted model forArabidopsis, in which light-activated CO overcomes the tempera

20、ture-dependent inhibition from FLC and induces the expression of FT in the phloem companion cells. FT is moved to the phloem and channelled to the apical meristem where it binds to FD and the complex is recruited into the nucleus. FTFD binds to the promoter of SOC1 and other meristematic floral integrators, changing the vegetative developmental programme to