Xu Yan, Miao Yuanxin, Cai Botao, Yi Qingping, Tian Xuejun, Wang Qihai, Ma Dan, Luo Qiong, Tan Feng, Hu Yongfeng
Hubei Engineering Research Center for Specialty Flowers Biological Breeding/College of Bioengineering, Jingchu University of Technology, Jingmen, China.
Center for Science Popularization Jingmen, Science and Technology Museum, Jingmen, China.
Front Plant Sci. 2022 Nov 2;13:1041095. doi: 10.3389/fpls.2022.1041095. eCollection 2022.
Histone deacetylase (HDAC) inhibitors (HDACis) have been widely used in plants to investigate the role of histone acetylation, particularly the function of HDACs, in the regulation of development and stress response. However, how histone acetylation is involved in rice () disease resistance has hardly been studied. In this paper, four HDACis including Sodium butyrate (NaBT), Suberoylanilide Hydroxamic Acid (SAHA), LBH-589 and Trichostatin A (TSA) were used to treat rice seedlings at different concentrations before inoculation of . We found that only 10mM NaBT treatment can significantly enhanced rice blast resistance. However, treatment of the four HDACis all increased global histone acetylation but at different sites, suggesting that the inhibition selectivity of these HDACis is different. Notably, the global H3K9ac level was dramatically elevated after both NaBT and LBH589 treatment although LBH589 could not enhance rice blast resistance. This indicates that the HDACs they inhibit target different genes. In accordance with the phenotype, transcriptomic analysis showed that many defense-related genes were up-regulated by NaBT treatment. Up-regulation of the four genes , , , were confirmed by RT-qPCR. ChIP-qPCR results revealed that H3K9ac level on these genes was increased after NaBT treatment, suggesting that these defense-related genes were repressed by HDACs. In addition, by promoter motif analysis of the genes that induced by both NaBT treatment and rice blast infection, we found that the motifs bound by ERF and AHL transcription factors (TFs) were the most abundant, which demonstrates that ERF and AHL proteins may act as the candidate TFs that recruit HDACs to defense-related genes to repress their expression when plants are not infected by rice blast.
组蛋白去乙酰化酶（HDAC）抑制剂（HDACis）已在植物中广泛用于研究组蛋白乙酰化的作用，特别是HDACs在发育调控和应激反应中的功能。然而，组蛋白乙酰化如何参与水稻抗病性的研究却很少。本文在接种稻瘟病菌之前，使用四种HDACis，包括丁酸钠（NaBT）、异羟肟酸（SAHA）、LBH-589和曲古抑菌素A（TSA），以不同浓度处理水稻幼苗。我们发现只有10mM NaBT处理能显著增强水稻对稻瘟病的抗性。然而，这四种HDACis处理均增加了整体组蛋白乙酰化，但位点不同，表明这些HDACis的抑制选择性不同。值得注意的是，尽管LBH589不能增强水稻对稻瘟病的抗性，但在NaBT和LBH589处理后，整体H3K9ac水平均显著升高。这表明它们抑制的HDACs靶向不同的基因。根据表型，转录组分析表明，许多防御相关基因在NaBT处理后上调。通过RT-qPCR证实了四个基因、、、的上调。ChIP-qPCR结果显示，NaBT处理后这些基因上的H3K9ac水平增加，表明这些防御相关基因被HDACs抑制。此外，通过对NaBT处理和稻瘟病感染诱导的基因进行启动子基序分析，我们发现与ERF和AHL转录因子（TFs）结合的基序最为丰富，这表明ERF和AHL蛋白可能作为候选TFs，在植物未被稻瘟病菌感染时，招募HDACs到防御相关基因上以抑制其表达。
