The Cysteine Protease CEP1, a Key Executor Involved in Tapetal Programmed Cell Death, Regulates Pollen Development in Arabidopsis
The Cysteine Protease CEP1, a Key Executor Involved in Tapetal Programmed Cell Death, Regulates Pollen Development in Arabidopsis
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半胱氨酸蛋白酶 CEP1 是参与绒毡层程序性细胞死亡的关键执行者，调节拟南芥花粉发育
DOI：
10.1105/tpc.114.127282
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发表时间：
2014
期刊：
影响因子：
11.6
通讯作者：
Lu Hai
中科院分区：
文献类型：
--
作者：
Zhang D;an;Liu Di;Lv Xiaomeng;Wang Ying;Xun Zhili;Liu Zhixiong;Li Fenglan;Lu Hai
绒毡层程序性细胞死亡（PCD）是被子植物花粉粒发育的先决条件，半胱氨酸蛋白酶是参与植物 PCD 的最普遍的水解酶。我们鉴定了一种类似木瓜蛋白酶的半胱氨酸蛋白酶 CEP1，它参与拟南芥绒毡层 PCD 和花粉发育。CEP1 在花药发育第 5 至 11 阶段的绒毡层中特异表达。 CEP1蛋白首先作为前体蛋白酶囊泡中的酶原出现，然后被转运至液泡，并在液泡破裂前转化为成熟的酶。cep1突变体表现出绒毡层PCD败育、花粉育性降低、花粉外壁异常。转录组分析显示，cep1突变体中有872个基因表达显着改变，其中大多数对绒毡层细胞壁组织、绒毡层分泌结构形成和花粉发育具有重要意义。CEP1过表达导致绒毡层过早PCD和花粉不育。 ELISA和定量RT-PCR分析证实CEP1表达水平与绒毡PCD程度和花粉育性有密切关系。我们的结果表明，CEP1 是绒毡层 PCD 过程中的关键执行者，并且正确的 CEP1 表达对于绒毡层细胞及时退化和功能性花粉形成是必要的。
Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development inArabidopsis thaliana.CEP1is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole.cep1mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in thecep1mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development.CEP1overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that properCEP1expression is necessary for timely degeneration of tapetal cells and functional pollen formation.