茎尖顶端分生组织（Shoot Apical Meristem，SAM）是植物胚胎后发育过程中地上部分不断生长并形成新器官的来源，其中干细胞群体的稳态维持受到多种因素的调控，是当前基础生物学研究领域的热点之一。我们的初步研究结果暗示，模式植物拟南芥TRANSPOTIN 1（AtTRN1）对SAM及其干细胞维持正常活性是必需的。通过遗传学筛选其突变体的抑制子，我们发现泛素连接酶KAKTUS（KAK）共同参与了这一生物学过程。酵母双杂交实验结果说明，它们的蛋白质之间存在直接相互作用。在此基础上，本课题拟通过筛选它们的互作蛋白来寻找可能参与这一过程的其它调节因子并进行相关验证，然后对这些相互作用的生物学意义进行研究，以期加深对该调控网络的了解。同时，本课题的部分成果也可能对AtTRN1和KAK参与的其它生物学途径的研究提供帮助。

In higher plants, shoot apical meristem (SAM) gives rise to all post-embryonic above-ground organs, and its proper functions require balanced maintenance of a group of so-called “stem cells”, which reside within SAM. However, it remains far to be clear how the homeostasis is regulated, therefore one of the hottest basic research topics for plant scientists. Our preliminary data indicated that, in model plant Arabidopsis thaliana, TRANSPOTIN 1 (AtTRN1) is required for SAM’s development and its stem cells’ activity. By genetic screening for suppressors of its mutant, KAKTUS (KAK), encoding a ubiquitin protein ligase, was identified. In addition, yeast two-hybrid experiments suggested that AtTRN1 and KAK physically interact. Based on these facts, we propose to further investigate the underlying mechanism by screening these two proteins’ interaction partners followed by studying related biological effects, in order to better understand their roles in this regulation network. It is also very possible that the results of this proposal are helpful for other biological processes in which AtTRN1 and KAK are involved.