Zhang Weilan, Ma Yingfei, Huang Yudi, He Min, Zhang Xiaoli, Xu Liang, Wang Yan, Liu Liwang, Zhu Yuelin
Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Sanya Institute, Nanjing Agricultural University, Nanjing 210095, PR China.
Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Sanya Institute, Nanjing Agricultural University, Nanjing 210095, PR China.
Plant Physiol Biochem. 2025 Feb;219:109439. doi: 10.1016/j.plaphy.2024.109439. Epub 2024 Dec 20.
Radish is an economically important root vegetable crop worldwide. Histone deacetylases (HDACs), one of the most important epigenetic regulators, play prominent roles in plant growth and development as well as abiotic stress responses. Nevertheless, the systematical characterization and critical roles of HDAC gene members in thermogenesis remains elusive in radish. Herein, a total of 21 RsHDAC genes were identified from the radish genome. Among them, two RsSRTs, six RsHDTs and 13 RsHDAs were classified into the SIR2, HD2 and RPD3/HDA1subfamily, respectively. The RNA-seq analysis indicated that three RsHDAs (RsHDA6.1, RsHDA6.2 and RsHDA19) and five RsHDTs exhibited high expression in vascular cambium of radish taproot. Both the RsHDT3 and RsHDA9 showed dramatically up-regulated expression under heat, salt and three heavy metals treatments. Moreover, the transient LUC reporter assay revealed that the promoter activity of the nucleus-localized RsHDA9 was intensely induced by heat stress. Intriguingly, overexpression of RsHDA9 promoted thermotolerance via enhancing proline accumulation and scavenging of reactive oxygen species in radish cotyledons, whereas the supplement of trichostatin A (TSA) led to the opposite phenotype. Notably, RsWRKY26 bound to the RsHDA9 promoter and activated its transcription to achieve enhancing thermotolerance in radish. Collectively, these findings would facilitate deciphering molecular mechanism underlying RsHDA9-mediated regulatory network of thermogenesis in radish.
萝卜是全球一种具有重要经济价值的根菜类作物。组蛋白去乙酰化酶（HDACs）是最重要的表观遗传调控因子之一，在植物生长发育以及非生物胁迫响应中发挥着重要作用。然而，HDAC基因成员在萝卜热生成中的系统表征和关键作用仍不清楚。在此，从萝卜基因组中总共鉴定出21个RsHDAC基因。其中，两个RsSRTs、六个RsHDTs和13个RsHDAs分别被归类到SIR2、HD2和RPD3/HDA1亚家族。RNA测序分析表明，三个RsHDAs（RsHDA6.1、RsHDA6.2和RsHDA19）和五个RsHDTs在萝卜主根的维管形成层中高表达。RsHDT3和RsHDA9在热、盐和三种重金属处理下均表现出显著上调的表达。此外，瞬时荧光素酶报告基因检测显示，核定位的RsHDA9的启动子活性在热胁迫下被强烈诱导。有趣的是，RsHDA9的过表达通过增强脯氨酸积累和清除萝卜子叶中的活性氧来提高耐热性，而添加曲古抑菌素A（TSA）则导致相反的表型。值得注意的是，RsWRKY26与RsHDA9启动子结合并激活其转录，从而在萝卜中增强耐热性。总的来说，这些发现将有助于阐明RsHDA9介导的萝卜热生成调控网络的分子机制。
