拟南芥mTERF14影响花药绒毡层PCD进程的功能研究

Programmed cell death (PCD) is an active and gene-regulated process which plays a vital role in tapetum degradation and anther development of plants. Arabidopsis mitochondrial transcription termination factor 14 (mTERF14) was a functional unknown and mitochondria-located mTERF family protein containing nucleotide binding domains, the deletion of mTERF14 gene leads to anther development retardation and delaying tapetum degradation, and mTERF14 gene and protein expressed in the position of tapetum PCD occurrence. Our previous study indicated that mTERF14 participate in tapetum PCD process. Accordingly, this study will focus on functional analysis of mTERF14 gene in tapetum PCD, screening of molecular targets of mTERF14, and mTERF14 regulation to mitochondrial genes. These results will shed light on the role of mTERF14 involved in tapetum PCD and provide theoretical and experimental basis for the relationship between mitochondrial gene regulation and anther development process (tapetum PCD).

细胞程序性死亡（PCD）是由基因控制的、主动的细胞死亡过程，对植物花药绒毡层降解起关键作用。拟南芥mTERF14是一个功能未知的线粒体转录终止因子家族成员，定位于线粒体，具有核酸结合结构域；mTERF14基因缺失导致花药发育延缓、绒毡层降解滞后等；mTERF14基因及蛋白在绒毡层PCD发生部位累积。初步结果表明mTERF14参与花药绒毡层PCD进程。据此，本项目将研究拟南芥mTERF14参与绒毡层PCD的基因功能，筛选mTERF14的分子靶标，分析mTERF14对相关线粒体基因的分子调控。研究结果将揭示mTERF14影响花药绒毡层发育的具体分子作用，为认识线粒体基因调控与花药发育过程（绒毡层PCD）的关系提供理论与实验依据。

线粒体从远古α变形杆菌进化而来，是细胞能量及物质代谢中心，与细胞的衰老、凋亡及干性密切相关。线粒体转录终止因子家族蛋白（mTERFs）调控线粒体的转录和蛋白翻译，动物中为四个成员，单个成员的缺失即造成胚胎致死或发育异常。植物中的mTERF为多拷贝，且随进化程度越高，数量越多。前期我们获得mterf14突变体，表现为花药发育延缓、绒毡层降解滞后等，mTERF14具有核酸结合结构域，其基因和蛋白表达在绒毡层PCD发生部位累积，但作用机制尚不清楚。通过本项目的资助进行了一系列的研究，结果表明mTERF14靶向结合线粒体的rRNA26和rRNA18，增加线粒体的拷贝数和基因表达，促进线粒体的合成，导致苹果酸累积，诱导细胞凋亡。