植物细胞程序性死亡（PCD）的分子调控机制是植物发育生物学研究的核心问题之一，但其研究深度远逊于动物领域。近年，由于一些突破性进展，该研究已成为植物发育领域的新热点，备受学者们关注。我们在前期工作中从烟草基细胞文库中克隆得到1个胚柄基部细胞特异表达的半胱氨酸蛋白酶抑制剂NtCYS，它可以通过调节蛋白酶C1A的活力来调控胚柄细胞程序性死亡的启动时间。最近，我们进一步发现NtCYS是一个双靶向半胱氨酸蛋白酶抑制剂，可同时抑制C1A和C13两个不同家族蛋白酶成员的活力。从而，为深入研究NtCYS调控胚柄细胞程序性死亡的分子机制提供了新的契机，由此切入，有可能揭示植物细胞PCD不同于动物细胞的独特机制。本项目拟以此为基础，通过分析C13的功能及NtCYS-C1A与NtCYS-C13两条途径之间的关系，系统揭示NtCYS调控胚柄细胞PCD的作用模式，以期对认识植物细胞PCD的分子调控机理有所突破。

Molecular mechanism underlying programmed cell death (PCD) in plant cells is one of the core questions in the field of plant developmental biology. Remarkable progresses have been made in understanding the regulatory pathways and its basic mechanisms of PCD in animal cells, but relatively little is known about PCD in plant cells. Recently, research on plant PCD has been paid great attention since some breakthroughes have been made and the importance of PCD for plant development has been further recognized. In our previous work, we identified a basal cell exclusively located cysteine protease inhibitor NtCYS. NtCYS-dependent protease C1A proteolytic pathway plays an important role in regulating the onset of suspensor PCD. Recently, NtCYS was approved as a bifunctional inhibitor, which can inhibit the activities of the peptidases both from peptidases C1A and C13 families. Thus, it offers a unique opportunity to investigate the regulatory mechanism of NtCYS in plant PCD extensively. In this project,we will focus on the revealing the function of peptidase C13 and the relationships between NtCYS-C1A and NtCYS-C13 pathways during suspensor PCD. Hope to enhance our understanding of the molecular mechanism regulating PCD in plants.