小麦早衰相关基因EYL的图位克隆和功能分析

In agricultural production, senescence is closely related to crop yield and quality improvement. Premature leaf senescence negatively impacts the yield and quality of crop. Up to now the study on premature senescence in wheat is mainly limited to the measurement of physiological and biochemical parameters and QTL linkage analysis. In addition to the NAC transcription factor, there are no other genes related to premature senescence to be reported. We found a line with premature leaf senescence in the hybrid progenies of two wheat varieties, Zhengmai9023 and Huanxiangguo. The results of the phenotypic identification indicated that the premature leaf senescence trait was determined by a single gene which was located on chromosome 4B. Based on above research results, the project is focused on: (1) Fine mapping and map based cloning of premature leaf senescence related gene, EYL; (2) The molecular and physiological mechanism of EYL gene regulating leaf function duration. The aims of the project are to elucidate the function of EYL gene in regulation of leaf function duration and provide gene resource for further genetic improvement of regulating leaf functional duration and increasing yield in wheat by using molecular breeding techniques such as genome editing and so on.

在农业生产中，衰老与农作物增产及品质改良密切相关。作物过早衰老必定影响产品产量和品质。目前对于小麦早衰的研究，大多限于早衰的生理和生化指标测定及其相关的QTL连锁分析，除NAC转录因子外，还未见其它早衰相关基因的报道。我们在郑麦9023与换香果的杂交后代中发现了一个叶片早衰的株系eyl，通过表型鉴定发现该性状是受单基因控制，并且已将该基因定位在4B染色体上。在此基础上，本项目主要研究：（1）早衰相关基因EYL的精细定位及图位克隆；（2）EYL基因调控叶片功能期的分子生理机制。以期阐明小麦早衰相关基因EYL在调控叶片功能期中的作用，为利用基因组编辑等分子育种技术调控叶片功能期和提高小麦产量的遗传改良提供基因资源及其依据。

为研究小麦早衰对小麦产量等农艺性状的影响，我们针对小麦早衰株系eyl做了以下几方面的研究：（1）早衰相关基因EYL的精细定位及图位克隆；（2）EYL基因调控叶片功能期的分子生理机制。研究结果表明：（1）穗粒数和千粒重降低是小麦早衰株系eyl籽粒产量降低的主要因素；（2）叶片中叶绿素含量降低及叶绿素组分a和b的不平衡可能是导致早衰植株eyl叶色变黄的主要原因；（3）早衰基因EYL参与了叶绿素和光合作用途径。本研究以期阐明小麦早衰相关基因EYL在调控叶片功能期中的作用，为利用分子育种技术调控叶片功能期和提高小麦产量的遗传改良提供基因资源及其依据。