Obtusifoliol 14a-demethylase OsCYP51G1 is involved in phytosterol synthesis and affects pollen and seed development
Obtusifoliol 14a-demethylase OsCYP51G1 is involved in phytosterol synthesis and affects pollen and seed development
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Obtusifoliol 14a-去甲基酶 OsCYP51G1 参与植物甾醇合成并影响花粉和种子发育
DOI：
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发表时间：
2020
影响因子：
3.1
通讯作者：
Kuaifei Xia
中科院分区：
文献类型：
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作者：
Zhengli Jiao;Weijuan Xu;Zeng Xuan;Xinlan Xu;Mingyong Zhang;Kuaifei Xia
植物甾醇作为生物膜的结构成分，不仅对多种细胞功能至关重要，而且是油菜素甾醇（BR）生物合成的前体。植物CYP 51是真核生物中最古老、最保守的钝叶醇14 α-脱甲基酶，是甾醇生物合成途径的重要组成部分。然而，对水稻（Oryza sativa L.）CYP51G1。结果表明，OsCYP 51 G1基因与钝叶醇14 α-脱甲基酶基因具有高度同源性，在水稻的大部分器官中均有强表达。亚细胞定位分析表明，OsCYP 51 G1定位于内质网。OsCYP 51 G1基因的敲除和敲除导致水稻开花延迟、膜完整性受损、花粉异常和籽粒产量降低，而OsCYP 51 G1基因的过表达则导致籽粒产量增加。OsCYP 51 G1的敲除还降低了终产物（谷甾醇和豆甾醇）的水平，并增加了上游中间产物的水平。OsCYP 51 G1介导的甾醇生物合成步骤的24-亚甲基-环阿屯烯醇和环桉叶烯醇。相反，OsCYP 51 G1的过表达增加了谷甾醇和豆甾醇的含量，降低了环桉叶烯醇的含量。然而，OsCYP 51 G1基因的RNAi敲除并没有导致这些与BR缺失相关的表型，如矮化、叶片直立和小种子，叶片角度对油菜素处理也不敏感。这些结果表明，水稻OsCYP 15 G1编码一种钝叶醇14 α-去甲基化酶，与其同源物OsCYP 51 G3不同，该酶在植物甾醇合成中可能不影响下游植物甾醇的合成。
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 14a-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 14a-demethylase and.OsCYP51G1 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 deficiencyrelated.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.14a-demethylase for the phytosterols biosynthesis and possible without affecting the biosynthesis of.downstream BRs, which was different from its homolog, OsCYP51G3.