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標題: | 一個蛋白質磷酸酶調控水稻根系發育的可塑性以適應水分過少和過多的情況 A protein phosphatase regulates plastic and inducible root architectures necessary for coping with too little or too much water in rice |
作者: | 呂俊賢 Chun-Hsien Lu |
指導教授: | 余淑美 Su-May Yu |
關鍵字: | PP2CABA,蛋白磷酸酶,防水層,側根的延伸,淹水,乾旱,WD40-194, PP2CABA,protein phosphatase,diffusion barriers,later root elongation,submergence,drought,WD40-194, |
出版年 : | 2024 |
學位: | 博士 |
摘要: | 在植物根系中,內皮層和外環組織中二次細胞壁的木質化和木栓質化所形成的多個防水層有利於水分和養分的運輸,維持細胞壁的機械強度,減少環境缺水時的水分流失和淹水時的氧氣流失,並為植物提供物理屏障隔絕土壤中的病原體和有毒化合物。在此研究中,我們發現了一個水稻蛋白磷酸酶PP2CABA,它通過感知 ABA 信號並調節木質素和木栓質生物合成,來調節多方面的植物結構。我們的研究顯示,PP2CABA調節的二次細胞壁提供了基本的結構和生理適應性,以應對植物生長期間在正常和乾旱逆境下土壤中不同的水分可用性。PP2CABA調控代謝資源的運用,進而改變根系結構的發育,並強化木質化和木栓質化所形成的防水層,以保護植物對抗乾旱與高滲透壓逆境。PP2CABA的表現受ABA、乾旱和鹽分誘導,其啟動子的活性在地上部與根部的延長區可被ABA活化。pp2caba突變株的二次細胞壁發育缺陷會影響氣孔發育、水分吸收和根系生長,導致光合作用和產量降低,並增加根部的徑向氧氣流失,導致不耐淹水。我們發現大量表現PP2CABA可抑制側根的延伸,在缺水條件下保存根部水分,並賦予植物對高滲透壓和乾旱逆境的耐受性。透過結合定量磷酸化蛋白質體學和基於TurboID的鄰近標記方法,我們鑑定了WD40-194是PP2CABA的一個生物受質。降低WD40-194的表現會促進 PP2CABA所調控的木質素和木栓質生物合成的基因的表現,並抑制側根的延伸,顯示WD40-194是木質素和木栓質生物合成的負向調控因子。我們的研究不僅揭示了對PP2CABA調節的訊息傳遞機制的新見解,調節根系發育的可塑性以適應土壤中不同的水分含量,而且還為提高作物的逆境耐受性提供了策略。 In plant roots, diffusion barriers formed by lignification and suberization of secondary cell walls in endodermal and peripheral tissues facilitate water and nutrient transport, sustain the mechanical strength of cell walls, reduce water loss during dehydration, prevent oxygen loss under waterlogging conditions, and provide physical barrier against pathogens and toxic compounds in the soil. In the present study, we discovered a rice protein phosphatase PP2CABA that regulates multifaceted plant structures by sensing the ABA signal and regulating lignin and suberin biosynthesis. We showed that the PP2CABA-regulated secondary cell walls offers basic structural and physiological fitness to cope with varying water availability in soil during plant growth under normal and drought stress conditions. PP2CABA regulates the relocation of metabolic resources, reprograms root architecture development, and reinforces lignified and suberized diffusion barriers to protect plants against drought and osmotic stresses. The expression of PP2CABA is induced by ABA, drought and salt, and its promoter is specifically activated by ABA in elongation zones of shoots and roots. Defective development of secondary cell walls in pp2caba mutant impairs stomatal development, water uptake, and root growth, leading to reduced photosynthesis and grain yield in fields, as well as increased radial oxygen loss to the anaerobic root rhizosphere, leading to submergence intolerance. We also found that PP2CABA overexpression inhibits later root elongation, conserves water in roots under dehydration, and confers plant tolerance to osmotic and drought stresses. By combining quantitative phosphoproteomics and TurboID-based proximity labeling approaches, we identified WD40-194 as a biological substrate of PP2CABA. Reduced expression of WD40-194 induces the expression of PP2CABA-regulated genes involved in lignin and suberin biosynthesis, and suppresses lateral root elongation, indicating WD40-194 is a negative regulator of lignin and suberin biosynthesis. Our studies reveal new insights into not only the mechanism of PP2CABA-regulated signaling network for programing root developmental plasticity in adaption to fluctuating water regimes in soil but also provide strategies for improving stress tolerance in crops. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/95694 |
DOI: | 10.6342/NTU202403968 |
全文授權: | 未授權 |
顯示於系所單位: | 基因體與系統生物學學位學程 |
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