RUPTURED POLLEN GRAIN1, a member of the MtN3/saliva gene family, is crucial for exine pattern formation and cell integrity of microspores in arabidopsis
RUPTURED POLLEN GRAIN1, a member of the MtN3/saliva gene family, is crucial for exine pattern formation and cell integrity of microspores in arabidopsis
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RUPTURED POLLEN GRAIN1 是 MtN3/唾液基因家族的成员，对于拟南芥小孢子的外壁图案形成和细胞完整性至关重要
DOI：
10.1104/pp.108.118026
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发表时间：
2008-06-01
期刊：
影响因子：
7.4
通讯作者：
Yang, Zhong-Nan
中科院分区：
文献类型：
--
作者：
Guan, Yue-Feng;Huang, Xue-Yong;Yang, Zhong-Nan
在小孢子形成过程中，小孢子母细胞（或小孢子）质膜在花粉壁发育中起着多种作用，包括胼胝质分泌、初胺沉积和外壁图案的决定。然而，参与这些过程的质膜蛋白仍然不为人所知。在这里，我们报道了一个新的基因RUPTURED POLLEN GRAIN1 (RPG1)，它编码一个质膜蛋白，是拟南芥（Arabidopsis thaliana）小孢子外叶模式形成所必需的。rpg1突变体表现出严重降低的雄性生育能力，其他表型正常，这主要是由于小孢子减数分裂后的流产。扫描电镜检查显示，突变体的外壁图案形成受到破坏，孢粉素随机沉积在花粉表面。透射电镜检查进一步发现，突变体小孢子在四分体阶段的原胺形成异常，导致小孢子和房室壁上有缺陷的孢子粉沉积。此外，rpg1突变体的小孢子破裂和细胞质渗漏明显，这表明突变体小孢子的细胞完整性受损。RPG1编码MtN3/唾液家族蛋白，该蛋白是质膜的组成部分。原位杂交分析显示，在雄性减数分裂过程中，RPG1在小孢子细胞和绒毡层中强烈表达。讨论了RPG1在小孢子发生中的可能作用。
During microsporogenesis, the microsporocyte ( or microspore) plasma membrane plays multiple roles in pollen wall development, including callose secretion, primexine deposition, and exine pattern determination. However, plasma membrane proteins that participate in these processes are still not well known. Here, we report that a new gene, RUPTURED POLLEN GRAIN1 (RPG1), encodes a plasma membrane protein and is required for exine pattern formation of microspores in Arabidopsis ( Arabidopsis thaliana). The rpg1 mutant exhibits severely reduced male fertility with an otherwise normal phenotype, which is largely due to the postmeiotic abortion of microspores. Scanning electron microscopy examination showed that exine pattern formation in the mutant is impaired, as sporopollenin is randomly deposited on the pollen surface. Transmission electron microscopy examination further revealed that the primexine formation of mutant microspores is aberrant at the tetrad stage, which leads to defective sporopollenin deposition on microspores and the locule wall. In addition, microspore rupture and cytoplasmic leakage were evident in the rpg1 mutant, which indicates impaired cell integrity of the mutant microspores. RPG1 encodes an MtN3/saliva family protein that is integral to the plasma membrane. In situ hybridization analysis revealed that RPG1 is strongly expressed in microsporocyte ( or microspores) and tapetum during male meiosis. The possible role of RPG1 in microsporogenesis is discussed.