枸杞根组织中类胡萝卜素代谢途径与ABA合成在逆境条件下的调节偶联机制

The regulation mechanism of ABA biosynthesis has not been demonstrated yet. Identification of all the components affecting active ABA content is essential for a complete understanding of the function of ABA in the plant. The carotenoids metabolism pathway and the ABA biosynthesis have a mutual regulation mechanism, the new challenge is to understand how the carotenoids metabolism pathway as a whole to regulate the ABA biosynthesis. The stress tolerant plant Lycium chinense Miller which has a big carotenoids pool size inside was chosen as the material in this project. Under the basis of transcriptome sequencing of Lycium chinense Miller, a series of carotenoids biosynthesis genes were cloned.In this project, the key steps of carotenoids metabolism pathway concerned with plant stress tolerance were demonstrated;the mutual regulation mechanism of carotenoids metabolism and ABA biosynthesis in the root of Lycium chinense Miller under stress conditions was clarified, and how the effect of time-spacec affecting the regulation mechanism is also demonstrated in deeply. The regulation mechenism between the exogenous ABA addition and the endogenous ABA variation was also discussed. In this project, from the point view of metabolic regulation, the ABA biosynthesis mechanisms was demonstrated deeply; and the regulation theory discussed in the project provide theoretical support and experimental guidance for createing resilience new varieties concerned with carotenoids metabolism pathway.

抗逆激素ABA的生物合成调节机制仍没有阐明。阐明影响活性ABA含量的所有因素是透彻理解这个激素功能的必要条件，ABA的合成与类胡萝卜素代谢途径存在调节与反馈调节关系，目前的关键问题是类胡萝卜素代谢途径如何参与ABA的合成调节？本项目选取抗逆能力强且类胡萝卜素含量较高的河北枸杞作为研究材料，在长期对其进行抗逆生理研究的基础上，对其进行了转录组测序，并克隆了系列类胡萝卜素合成酶基因。以此作为研究基础，本项目将探明与植物根部抗逆密切相关的类胡萝卜素代谢途径关键基因；探讨在逆境条件下枸杞根部类胡萝卜素代谢途径变化对ABA含量以及植物抗逆能力的调节机制，进一步揭示时空效应对此调节机制的调控影响；分析外源ABA施加是如何通过影响内源ABA从而反馈调节类胡萝卜素代谢途径。本研究从代谢调控的角度深入研究ABA生物合成机制，并为从类胡萝卜素为出发点研究植物抗逆理论和创制抗逆新品种提供理论支持和实践指导。

类胡萝卜素是广泛存于在自然界中一组结构多样的天然色素。在高等植物中，参与光复合体的光捕获；保护光氧化损伤；是植物激素ABA的前体。枸杞富含类胡萝卜素且具有很强的环境适应性。为了研究枸杞中类胡萝卜素代谢途径与植物激素ABA在逆境条件下的调节机制。本课题首次从枸杞中分离到类胡萝卜素生物合成途径及分解代谢途径的系列关键基因14个。利用大肠杆菌的颜色互补实验和HPLC分析对克隆到的基因所编码的酶进行生物活性鉴定。通过农杆菌介导的遗传转化体系转化烟草，在模式植物烟草中对于类胡萝卜素代谢途径的关键酶基因逆境条件下的调控机制进行了分析，阐明了类胡萝卜素代谢途径在植物抗逆，抗氧化过程中发挥的重要作用。同时揭示出类胡萝卜素代谢途径的抗逆机制与植物关键激素ABA之间的合成调节关系。本研究明确指出了了类胡萝卜素代谢途径上游合成部分的关键基因在植物逆境胁迫中发挥重要作用但是并不直接影响ABA的合成，同时类胡萝卜素下游合成及分解途径的关键基因如NCED直接参与影响了植物激素ABA的调节过程，从而影响了植物的抗逆境能力。本研究同时诱导了枸杞的发状根组织，探讨了类胡萝卜素关键基因在根组织的逆境调控作用。本研究从代谢调控的角度深入研究ABA生物合成机制，并为从类胡萝卜素为出发点研究植物抗逆理论和创制抗逆新品种提供理论支持和实践指导。项目执行三年来，发表核心期刊论文4篇，SCI论文8篇，申请专利1项；培养博士生2名，硕士生2名。