Table 2_A CW-type zinc finger protein is involved in RES-oxylipin signaling and the response to abiotic stress in Arabidopsis thaliana.xlsx

IntroductionOxylipins regulate the response of plants to biotic and abiotic stress factors and the tolerance of unfavorable conditions. While the signaling pathway of jasmonic acid has been intensively studied, little is known about the signal transduction that mediates the responses of reactive electrophile oxylipins such as 12-oxo phytodienoic acid and prostaglandins.
Methods and resultsHere, a CW-type zinc finger protein (ZIFI1, At3g62900) was identified as a new signaling factor in a mutant screen. Transcriptome analysis of Arabidopsis mutants with a defect in this gene showed that the zinc finger protein is involved in regulating gene expression. Only about half (327 genes) of the about 646 genes induced by the reactive electrophilic oxylipin prostaglandin in the wild type was also up-regulated in the zifi1 mutant. The differentially expressed genes are enriched in genes related to detoxification and responses to stress factors such as oxidative stress. Therefore, it was tested whether a defect in the zinc finger gene resulted in altered sensitivity to stress factors. The sensitivity to the reactive oxygen species butyl hydroperoxide and to the xenobiotic triiodobenzoic acid was increased in the mutant. In addition, production of reactive oxygen species induced by the bacterial elicitor flg22 was accelerated.
DiscussionThe results provide new insights into the factors involved in the signaling of reactive electrophiles and the connection of different stress signaling pathways.

引言
氧脂素（oxylipins）可调控植物对生物及非生物胁迫因子的响应，以及植物对不良环境的耐受能力。尽管茉莉酸（jasmonic acid）信号通路已得到深入研究，但介导活性亲电性氧脂素（如12-氧植物二烯酸与前列腺素）响应的信号转导机制仍知之甚少。

方法与结果
本研究通过突变体筛选，鉴定得到一种CW型锌指蛋白（ZIFI1，At3g62900）作为新型信号调控因子。对该基因功能缺陷的拟南芥（Arabidopsis）突变体开展转录组分析后发现，该锌指蛋白参与基因表达调控。在野生型植株中，活性亲电性氧脂素前列腺素诱导的约646个基因中，仅约半数（327个基因）在zifi1突变体中同样呈现上调表达。差异表达基因显著富集于解毒相关以及氧化应激等胁迫响应类基因。据此，本研究进一步验证该锌指基因的缺陷是否会改变植株对胁迫因子的敏感性：结果显示，突变体对活性氧衍生物丁基过氧化氢以及异生物质三碘苯甲酸的敏感性均显著提升。此外，细菌激发子flg22诱导的活性氧迸发过程也被加速。

讨论
本研究结果为活性亲电物质信号转导相关因子的研究，以及不同胁迫信号通路间的关联机制提供了全新的见解。