Syntaxin of plants31 (SYP31) and SYP32 is essential for Golgi morphology maintenance and pollen development
Syntaxin of plants31 (SYP31) and SYP32 is essential for Golgi morphology maintenance and pollen development
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植物突触融合蛋白 31 (SYP31) 和 SYP32 对于高尔基体形态维持和花粉发育至关重要
DOI：
10.1093/plphys/kiab049
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发表时间：
2021-02-12
期刊：
影响因子：
7.4
通讯作者：
Bao, Yiqun
中科院分区：
文献类型：
--
作者：
Rui, Qingchen;Tan, Xiaoyun;Bao, Yiqun
花粉发育是被子植物有性生殖的关键过程。高尔基体在花粉发育过程中起着重要的作用，它负责细胞壁物质的合成和运输。然而，对维持植物高尔基体完整性的分子机制知之甚少。植物突触融合蛋白（syntaxin of plants，SYP）3家族蛋白SYP 31和SYP 32是拟南芥中仅有的两个定位于高尔基体的可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（N-ethylmaleimide sensitive factor attachment protein receptor，SNARE），其内源性功能尚不清楚。在这里，我们展示了SYP 31和SYP 32在调节高尔基体形态和花粉发育中的作用。syp 31/+ syp 32/+双突变体的两个独立的系是雄性配子体致死的; syp 31 syp 32突变的零传递率通过pSYP 32：SYP 32而不是pSYP 32：SYP 31转基因恢复到基本正常的水平，表明它们在花粉发育中的功能差异。syp 31 syp 32花粉的初始停滞发生在从小孢子到双细胞阶段的过渡期间，在花粉有丝分裂I（PMI）中细胞板的形成和内壁的沉积异常。在syp 31 syp 32花粉，高尔基池的数量和长度显着减少，伴随着许多周围的小泡，这可能在很大程度上归因于缺陷的顺行和逆行运输路线。SYP 31和SYP 32直接与保守的寡聚体高尔基体（COG）复合物的亚基COG 3相互作用，并负责其高尔基体定位，为SYP 31/32在高尔基体内运输中的功能提供了潜在机制。我们认为SYP 31和SYP 32通过调节蛋白质运输和高尔基体结构在花粉发育中发挥部分冗余作用。
Pollen development is a key process for the sexual reproduction of angiosperms. The Golgi plays a critical role in pollen development via the synthesis and transport of cell wall materials. However, little is known about the molecular mechanisms underlying the maintenance of Golgi integrity in plants. In Arabidopsis thaliana, syntaxin of plants (SYP) 3 family proteins SYP31 and SYP32 are the only two Golgi-localized Qa-soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs) with unknown endogenous functions. Here, we demonstrate the roles of SYP31 and SYP32 in modulating Golgi morphology and pollen development. Two independent lines of syp31/+ syp32/+ double mutants were male gametophytic lethal; the zero transmission rate of syp31 syp32 mutations was restored to largely normal levels by pSYP32:SYP32 but not pSYP32:SYP31 transgenes, indicating their functional differences in pollen development. The initial arrest of syp31 syp32 pollen occurred during the transition from the microspore to the bicellular stage, where cell plate formation in pollen mitosis I (PMI) and deposition of intine were abnormal. In syp31 syp32 pollen, the number and length of Golgi cisterna were significantly reduced, accompanied by many surrounding vesicles, which could be largely attributed to defects in anterograde and retrograde trafficking routes. SYP31 and SYP32 directly interacted with COG3, a subunit of the conserved oligomeric Golgi (COG) complex and were responsible for its Golgi localization, providing an underlying mechanism for SYP31/32 function in intra-Golgi trafficking. We propose that SYP31 and SYP32 play partially redundant roles in pollen development by modulating protein trafficking and Golgi structure.