Obtusifoliol 14α-demethylase OsCYP51G1 is involved in phytosterol synthesis and affects pollen and seed development
Obtusifoliol 14α-demethylase OsCYP51G1 is involved in phytosterol synthesis and affects pollen and seed development
复制标题
Obtusifoliol 14 α-去甲基酶 OsCYP51G1 参与植物甾醇合成并影响花粉和种子发育
DOI：
10.1016/j.bbrc.2020.05.216
复制
发表时间：
2020-08-13
影响因子：
3.1
通讯作者：
Xia, Kuaifei
中科院分区：
文献类型：
--
作者：
Jiao, Zhengli;Xu, Weijuan;Xia, Kuaifei
植物甾醇作为生物膜的结构成分，不仅是多种细胞功能所必需的，也是油菜素类固醇(BR)生物合成的前体。植物细胞色素P51是真核生物中最古老和最保守的固氮素14α-脱甲基酶，是甾醇生物合成途径的重要组成部分。然而，人们对水稻的研究却知之甚少。细胞色素P51G1.在这项研究中，我们发现水稻OsCYP51G1与Obtusifoliol 14α-去甲基酶有很高的同源性，OsCYP51GI在水稻的大部分器官中都有强烈的表达。亚细胞定位分析表明，OsCYP51G1定位于内质网。OsCYP51G1基因的敲除和敲除导致开花延迟，膜完整性受损，花粉异常，籽粒产量下降，而OsCYP51G1过表达则导致籽粒产量增加。OsCYP51G1基因的敲除还降低了OsCYP51G1介导的甾醇生物合成过程中最终产物(谷甾醇和豆甾醇)的水平，增加了上游中间产物(24-亚甲基-环青藤醇和环优树烯醇)的水平。与之相反，过表达OsCYP51G1增加了谷甾醇和豆甾醇的含量，降低了环优树烯醇的含量。然而，RNAi对OsCYP51G1的敲除并没有诱导出这些与BR缺乏相关的表型，如矮化、直立叶片和小种子，叶片角度对油菜素内酯处理也不敏感。这些结果表明，水稻OsCYP15G1编码一个用于植物甾醇生物合成的Obtusifoliol 14α-去甲基酶，并且可能不影响下游BRs的生物合成，这与其同源基因OsCYP51G3不同。(C)2020 Elsevier Inc.保留所有权利。
As structural components of biological membranes, phytosterols are essential not only for a variety of cellular functions but are also precursors for brassinosteroid (BR) biosynthesis. Plant CYP51 is the oldest and most conserved obtusifoliol 14 alpha-demethylase in eukaryotes and is an essential component of the sterol biosynthesis pathway. However, little is known about rice (Oryza sativa L.) CYP51G1. In this study, we showed that rice OsCYP51G1 shared high homology with obtusifoliol 14 alpha-demethylase and OsCYP51GI was strongly expressed in most of rice organs. Subcellular localization analysis indicated that OsCYP51G1 was localized to the endoplasmic reticulum. Knockdown and knockout of OsCYP51G1 resulted in delayed flowering, impaired membrane integrity, abnormal pollen, and reduced grain yield, whereas OsCYP51G1 overexpression led to increased grain yield. Knockdown of OsCYP51G1 also reduced the levels of end-products (sitosterol and stigmasterol) and increased those of upstream intermediates (24-methylene-cycloartenol and cycloeucalenol) of the OsCYP51G1-mediated sterol biosynthesis step. In contrast, overexpression of OsCYP51G1 increased the sitosterol and stigmasterol content and reduced that of cycloeucalenol. However, knockdown of OsCYP51G1 by RNAi did not elicit these BR deficiency-related phenotypes, such as dwarfism, erect leaves and small seeds, nor was the leaf lamina angle sensitive to brassinolide treatment. These results revealed that rice OsCYP15G1 encodes an obtusifoliol 14 alpha-demethylase for the phytosterols biosynthesis and possible without affecting the biosynthesis of downstream BRs, which was different from its homolog, OsCYP51G3. (C) 2020 Elsevier Inc. All rights reserved.