孙淑豪　胡彦如　余迪求

摘要： HDACs（Histone deacetylase）家族蛋白质负责组蛋白H3K4和H4K19脱乙酰化，并参与植物生长和应激反应的信号转导过程。茉莉酮酸酯Jasmonates（JA）是一种重要的天然植物激素，不仅调节植物生长和发育而且还参与植物对多种逆境胁迫响应的信号转导和调控过程。但是，HDACs在植物中参与JA信号转导的具体机制目前还不是很清楚。该研究以HDA19（Histone deacetylase 19）为对象，探讨了HDACs在植物JA信号转导中的功能和作用。结果表明：HDA19的TDNA插入纯合突变体在JA处理条件下没有出现明显的JA根长反应。在相同处理条件下，hda19的不同突变体株系与相同生态型背景的野生型植株（WT）花色素苷含量无显著差异，但下游JAZ1、VSP1等JA信号通路的标记基因都显著上调表达。同时，hda19相比于WT对真菌Botrytis cineara的抗性显著增强，且hda19中下游基础防御标记基因PDF1.2、Thi2.1、ERF1等的表达水平显著高于WT。基于上述研究结果，该研究认为HAD19通过JA信号通路负调控拟南芥对真菌B. cineara的防御反应。

关键词： HDA19， JA， Botrytis cineara， 生物胁迫

中图分类号： Q945.78

文献标识码： A

文章编号： 10003142（2017）11135513

Abstract： HDACs （Histone deacetylase） family proteins are responsible for the deacetylation of histones H3K4 and H4K19 and are involved in signal transduction processes of plant growth and stress. Jasmonates（JA） is an important natural plant hormone that not only regulates plant growth and development but also participates in the process of signal transduction and regulation of plant responses to multiple stress conditions. However， the specific mechanism by which HDACs participate in JA signal transduction is not very clear. We investigated the function and role of HDACs in plant JA signal transduction with HDA19 （Histone deacetylase 19）. In this study， we found that the HDA19 TDNA insertion homozygous mutant did not show a significant JA root length response treated by MeJA. Under the same conditions， there was no significant difference in anthocyanin content between different mutant lines of hda19 and WT plants of the same ecotype background. However， JAZ1， VSP1 and other downstream JA signaling pathway marker genes were significantly upregulated expression. At the same time， the resistance of hda19 to fungi Botrytis cineara was significantly enhanced compared with WT， and the expression levels of basic defense marker genes PDF1.2， Thi2.1 and ERF1 were significantly higher than WT in hda19. Based on these results， we believe that HAD19 negatively regulates Arabidopsis thaliana defense against Botrytis cineara via JA signaling pathway.

Key words： HDA19， JA， Botrytis cineara， biological stress

在自然界中，植物不僅受到非生物条件，如干旱、寒冷、冷冻、高温和洪水的威胁；而且还受到病毒、细菌、真菌和昆虫等病原体引起的生物胁迫的侵害。在长期的进化过程中，植物和病原体不断相互适应，使植物进化出一系列防御措施来抵抗病原体的侵染。植物针对细菌或真菌病原体的免疫应答，主要通过依赖于一组病原体相关分子模式（pathogen associated molecular pattern， PAMP）的模式识别受体（pattern recognition receptor，PRR）来识别保守的病原体信号分子（Boller & He，2009）。 PTI（PAMPtriggered immunity）抗性病毒病原体的功能已在哺乳动物细胞中得到报道，但在植物中尚未完全了解（Calil & Fontes，2016）。……