外源性碳源对花后干旱胁迫下小麦Rubisco和GS基因表达及产量形成的影响

Carbon and nitrogen dynamic balance runs through the whole life cycle in plants. Drought stress occuring in any growth period would break the dynamic balance, and the crop yield would be limited. Simultaneously, there are some monitoring mechanisms of carbon-nitrogen balance in plant. Some signal molecules, such as sugar, hormone, organic acids and other substances can play a regulatory role by regulating the gene expression in the process of carbon-nitrogen metabolism. Wheat carbon-nitrogen balance would be affacted by drought stress during filling stage, causing serious yield losses. How to alleviate the adverse effects of drought stress on wheat growth is one of the crucial scientific problems. Especially that a low cost and high efficiency way can solve the problems of production practice lacks corresponding research. In this situation, on the basis of crop chemical regulation, this project which combined with the traditional technology of crop cultivation studied the effects of different exogenous carbon source on Rubisco and GS gene expression and yield formation in wheat grown under drought stress from anthesis to maturity by means of advanced molecular biology technology, and then analyzed the two genes expression and potential contribution on carbon and nitrogen dynamic balance, further clarified effect of exogenous carbon source on yield formation in wheat grown under drought stress from anthesis to maturity to provide a basis of water saving cultivation of wheat, drought resistance molecular regulation and resilience emergency measures.

作物体内存在碳、氮动态平衡，这种平衡贯穿作物整个生命周期；干旱胁迫无论发生在哪个生育阶段都将打破这种动态平衡，并影响作物产量。同时，作物体内存在监视碳、氮平衡的机制，一些信号分子如糖、激素、有机酸等物质会通过影响碳、氮代谢过程中基因的表达起调控作用。花后干旱显著影响小麦灌浆期间植株的碳、氮平衡，并使产量造成严重损失。如何缓解干旱胁迫对小麦产生的不利影响，一直都是农业生产面临的难题，特别是如何节本、高效的解决这一问题还缺乏相应的研究。针对这一现状，本项目以作物化学调控技术为基础，以先进的分子生物学技术为工具，结合传统的作物栽培学技术，研究不同外源性碳源对花后干旱胁迫下小麦Rubisco和GS基因表达特性的影响，进而分析其二者的表达情况对小麦碳、氮平衡的调控作用和潜在贡献，进一步阐明外源性碳源对花后干旱下小麦产量形成的影响，为小麦节水栽培、抗旱分子调控及抗逆应变措提供依据。

干旱胁迫会打破作物体内的碳、氮动态平衡，并将影响作物产量；外源性碳源可以缓解干旱胁迫对作物产生的不利影响，但其作用机理尚不清楚。通过一系列研究，我们发现通过施用适宜浓度的外源性碳源能够显著缓解干旱胁迫对小麦产生的不利影响；初步结果表明不同的外源性碳源对小麦的保护机制并不相同。因此，本项目从作物碳、氮代谢为切入点，以先进的分子生物学技术为工具，深入研究外源性碳源对干旱胁迫下小麦Rubisco和GS基因表达特性的影响，揭示Rubisco和GS基因表达对小麦碳、氮代谢的调控作用。 不同外源性碳源对干旱胁迫下小麦的调控效果除了涉及到渗透调节，翻译后调控机制也可能起到重要作用。研究结果将为揭示外源性碳源对花后干旱胁迫下小麦产量形成的影响提供新的科学依据。