烟草叶片在二氯喹啉酸胁迫下的蛋白组学分析

Proteomic Analysis of Tobacco Leaves under Quinclorac Stress

为明确二氯喹啉酸对烟草药害的机理,采用同位素标记相对和绝对定量(i TRAQ)技术分析了二氯喹啉酸处理7 d后烟草畸形叶片较正常叶片的蛋白组学变化。本研究共鉴定出65个差异蛋白,其中表达量上调的23个,下调的42个,它们具有结合、催化和转运等分子功能。分别参与光合作用、防御/抗胁迫、代谢等细胞过程,荧光定量PCR验证结果与蛋白组学数据一致。ABA合成通路中的ABA2及NCED基因能够响应二氯喹啉酸胁迫信号,分别在处理后48和24 h达到表达高峰,处理后72 h下调至较低水平。根据这种上调表达后又迅速下调的基因表达模式,推测烟草体内存在一种应激机制抵抗二氯喹啉酸胁迫。本研究首次在烟草中采用蛋白组学的方法分析二氯喹啉酸胁迫下基因的表达变化,并获得重要候选基因。

To clarify the phytotoxicity mechanism of quinclorac to tobacco,the isobaric-labeled relative and absolute quantitative(iTRAQ)technology was used to analyze the proteomic changes of tobacco malformed leaves compared with normal leaves after7days of quinclorac treatment.A total of65differentially expressed proteins were identified,of which23were up-regulated and42were down-regulated.They were involved in biological processes such as photosynthesis,defense/anti-stress,and cellular metabolites respectively,and had molecular functions such as binding,catalysis and transport.Fluorescent quantitative polymerase chain reaction(qPCR)results were consistent with the proteomics data.Two key genes in abscisic acid(ABA)synthesis pathway,ABA2and the9-cis-epoxycarotenoid dioxygenase NCED gene,responded to quinclorac stress signals,reached peak expression at48and24h after treatment,and decreased to baseline level at72h after treatment.The gene profile of up-regulated expression followed by rapid down regulation suggests that tobacco has a mechanism for resisting quinclorac stress.This study analyzed the expression changes of tobacco leaf proteins under quinclorac stress and obtained important differentially expresed proteins.