Zhang Huihui, Wang Menglong, Li Yiqi, Yan Wei, Chang Zhenyi, Ni Haoling, Chen Zhufeng, Wu Jianxin, Xu Chunjue, Deng Xing Wang, Tang Xiaoyan
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.
Shenzhen Institute of Molecular Crop Design, Shenzhen, 518107, China.
J Integr Plant Biol. 2020 Oct;62(10):1574-1593. doi: 10.1111/jipb.12919. Epub 2020 Mar 24.
Pollen exine contains complex biopolymers of aliphatic lipids and phenolics. Abnormal development of pollen exine often leads to plant sterility. Molecular mechanisms regulating exine formation have been studied extensively but remain ambiguous. Here we report the analyses of three GDSL esterase/lipase protein genes, OsGELP34, OsGELP110, and OsGELP115, for rice exine formation. OsGELP34 was identified by cloning of a male sterile mutant gene. OsGELP34 encodes an endoplasmic reticulum protein and was mainly expressed in anthers during pollen exine formation. osgelp34 mutant displayed abnormal exine and altered expression of a number of key genes required for pollen development. OsGELP110 was previously identified as a gene differentially expressed in meiotic anthers. OsGELP110 was most homologous to OsGELP115, and the two genes showed similar gene expression patterns. Both OsGELP110 and OsGELP115 proteins were localized in peroxisomes. Individual knockout of OsGELP110 and OsGELP115 did not affect the plant fertility, but double knockout of both genes altered the exine structure and rendered the plant male sterile. OsGELP34 is distant from OsGELP110 and OsGELP115 in sequence, and osgelp34 and osgelp110/osgelp115 mutants were different in anther morphology despite both were male sterile. These results suggested that OsGELP34 and OsGELP110/OsGELP115 catalyze different compounds for pollen exine development.
花粉外壁含有脂肪族脂质和酚类的复杂生物聚合物。花粉外壁的异常发育常常导致植物不育。调控外壁形成的分子机制已得到广泛研究，但仍不明确。在此，我们报告了对三个GDSL酯酶/脂肪酶蛋白基因OsGELP34、OsGELP110和OsGELP115在水稻外壁形成过程中的分析。OsGELP34是通过克隆一个雄性不育突变基因鉴定出来的。OsGELP34编码一种内质网蛋白，主要在花粉外壁形成过程中的花药中表达。osgelp34突变体表现出外壁异常以及花粉发育所需的一些关键基因的表达改变。OsGELP110先前被鉴定为在减数分裂花药中差异表达的基因。OsGELP110与OsGELP115最为同源，这两个基因表现出相似的基因表达模式。OsGELP110和OsGELP115蛋白均定位于过氧化物酶体。单独敲除OsGELP110和OsGELP115不影响植株育性，但两个基因的双敲除改变了外壁结构并导致植株雄性不育。OsGELP34在序列上与OsGELP110和OsGELP115距离较远，且osgelp34和osgelp110/osgelp115突变体尽管均为雄性不育，但花药形态不同。这些结果表明，OsGELP34和OsGELP110/OsGELP115催化不同的化合物用于花粉外壁发育。
