干旱和盐胁迫下水稻类受体蛋白激酶OsESG1调控根系发育的研究

The root system plays a crucial and indispensable role in plant growth. The molecular mechanism of root architecture regulated by environmental signals has not been well disentangled. In our previous work, a receptor like protein kinase OsESG1 that negatively regulates elongation of primary roots and morphogenesis of lateral roots has been isolated, and it could be induced to expressed in root under drought and salt stress. This project aims to uncover OsESG1 regulatory mechanism in rice early root development. Illuminate the function of OsESG1 during root architecture and morphogenesis through regulation of auxin transport and signal transduction under drought and salt stress. Dissection of the transcription regulatery mechanism for OsESG1 by transcriptome analysis. The research will be valuble in understanding of molecular mechanism of rice root morphogenesis, and also provides important theoretical basis and gene resources for improving the comprehensive resistance of rice.

根系对整个植物的生长发育起着关键性的作用，环境信号调控根系形态建成的分子机制目前还不是很清楚。初步研究发现，水稻类受体蛋白激酶（RLKs）OsESG1能够抑制水稻早期主根的伸长和侧根的发生，并且干旱和盐胁迫处理能诱导OsESG1的表达。本项目拟开展对OsESG1调控水稻根系早期发育的生物学功能研究。分析确定在干旱和盐胁迫下，OsESG1作为膜受体在感知外界胁迫信号后通过调控生长素极性运输和信号转导进而调控根系的形态建成。通过转录组的差异比较，解析OsESG1对整个根系的转录调控机制。该项目对阐明水稻根系发育的分子机制具有重要意义，为培育抗逆新品种提供理论依据和基因资源。

类受体蛋白激酶属于蛋白激酶的一个亚家族，作为重要的信号分子受体，广泛参与胁迫信号转导及调控植物生长发育过程。本项目研究发现，水稻类受体蛋白激酶（RLKs）OsESG基因能够被干旱，盐和ABA所诱导，该蛋白具有自磷酸化活性，而且能够磷酸化底物蛋白MBP和His。通过转化反义OsESG1基因获得了OsESG1抑制转基因株系。转基因株系早期不定数数目减少，茎基部生长素响应基因及生长素转运基因的表达发生了改变。干旱胁迫处理后，OsESG1转基因株系的抗旱性被削弱，抗氧化防御系统和抗逆基因的表达被削弱。这些结果表明OsESG1参与调控水稻早期不定根发育和干旱抗性。本项目对阐明水稻根系发育的分子机制具有重要意义，为培育抗逆新品种提供理论依据和基因资源。