Mutation in a putative glycosyltransferase-like gene causes programmed cell death and early leaf senescence in rice
Mutation in a putative glycosyltransferase-like gene causes programmed cell death and early leaf senescence in rice
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假定的糖基转移酶样基因突变导致水稻程序性细胞死亡和叶片早期衰老
DOI：
10.1186/s12284-019-0266-1
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发表时间：
2019-02-13
期刊：
影响因子：
5.5
通讯作者：
Zhang, Xiang-Qian
中科院分区：
文献类型：
--
作者：
Ke, Shanwen;Liu, Shuchun;Zhang, Xiang-Qian
叶片衰老是一个受遗传调控的高度复杂有序的过程。虽然人们对叶片衰老进行了广泛的研究，但其机理还不十分清楚。在本研究中，我们分离到一个水稻突变体，命名为早衰叶（psl），该突变体在开花后表现出早衰和自发的类病斑表型。psl突变体显示程序性细胞死亡，活性氧（ROS）的积累增加。分子和遗传分析表明，这些表型是由于OsPSL（LOC_Os12g42420）中的苯丙氨酸缺失引起的，OsPSL编码一个推测的核心2/I分支β-1，6-N-乙酰葡糖胺转移酶，该转移酶被预测参与蛋白质糖基化修饰。此外，在psl突变体中观察到O-连接N-乙酰葡萄糖胺（O-GlcNAc）转移酶（OGT）基因的转录水平显著下调，支持O-糖基化修饰受损的发生。蛋白质组学分析表明，与野生型相比，psl突变体中乙烯相关的代谢酶，包括S-腺苷甲硫氨酸（SAM）合成酶（SAMS）显著上调。与蛋白质组学结果一致，乙烯浓度在psl突变体中比在野生型植物中更高，并且乙烯合成和信号转导基因的转录水平在psl突变体中被诱导。乙烯生物合成抑制剂氨基乙氧乙烯甘氨酸处理可部分挽救早老叶片衰老。这些结果突出了蛋白质O-糖基化在PCD和叶片衰老中的重要性，并表明OsPSL在乙烯信号传导中可能起作用。
Leaf senescence is a genetically regulated, highly complex and ordered process. Although it has been extensively studied, the mechanism of leaf senescence is not well understood. In this study, we isolated a rice mutant, designated as premature senescence leaf (psl), which exhibits early senescence and spontaneous lesion mimic phenotype after flowering. Thepslmutant displays programmed cell death with elevated accumulation of reactive oxygen species (ROS). Molecular and genetic analyses revealed that the phenotypes were caused by a phenylalanine deletion in theOsPSL(LOC_Os12g42420) that encode a putative core 2/I branching beta-1,6-N-acetylglucosaminyl transferase predicted to be involved in protein glycosylation modification.OsPSLmRNA levels increased as senescence progressed, with maximum accumulation of transcripts at late senescence stages in WT plants. Moreover, remarkedly down-regulated transcriptional levels of O-linked N-acetylglucosamine (O-GlcNAc) transferases (OGTs) genes were observed inpslmutant, supporting the occurrence of impaired O-glycosylation modification. Proteomic analysis showed that ethylene-related metabolic enzymes including S-adenosyl methionine (SAM) synthetase (SAMS) were significantly upregulated in thepslmutant compared with WT. Consistent with the proteomic results, ethylene concentration is higher inpslmutant than in wild-type plants, and transcript levels of ethylene synthesis and signal transduction genes were induced inpslmutant. The early leaf senescence ofpslcan be partially rescued by ethylene biosynthesis inhibitor aminoethoxyvinylglycine treatment. These results highlight the importance of protein O-glycosylation in PCD and leaf senescence, and suggest a possible role of OsPSL in ethylene signaling.