Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Agricultural College, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Int J Mol Sci. 2023 Mar 2;24(5):4849. doi: 10.3390/ijms24054849.
High temperature stress (HTS), with growth and development impairment, is one of the most important abiotic stresses frequently encountered by plants, in particular solanacaes such as pepper, that mainly distribute in tropical and subtropical regions. Plants activate thermotolerance to cope with this stress; however, the underlying mechanism is currently not fully understood. SWC4, a shared component of SWR1- and NuA4 complexes implicated in chromatin remodeling, was previously found to be involved in the regulation of pepper thermotolerance, but the underlying mechanism remains poorly understood. Herein, PMT6, a putative methyltranferase was originally found to interact with SWC4 by co-immunoprecipitation (Co-IP)-combined LC/MS assay. This interaction was further confirmed by bimolecular fluorescent complimentary (BiFC) and Co-IP assay, and PMT6 was further found to confer SWC4 methylation. By virus-induced gene silencing, it was found that PMT6 silencing significantly reduced pepper basal thermotolerance and transcription of and significantly reduced the enrichment of chromatin-activation-related H3K9ac, H4K5ac, and H3K4me3 in TSS of , which was previously found to be positively regulated by CaSWC4. By contrast, the overexpression of PMT6 significantly enhanced basal thermotolerance of pepper plants. All these data indicate that PMT6 acts as a positive regulator in pepper thermotolerance, likely by methylating SWC4.
高温胁迫（HTS）会损害生长和发育，是植物经常遇到的最重要的非生物胁迫之一，特别是辣椒等茄科植物，它们主要分布在热带和亚热带地区。植物会激活耐热性来应对这种胁迫；然而，其潜在机制目前还不完全清楚。SWC4 是 SWR1 和 NuA4 复合物的一个共享成分，参与染色质重塑，先前被发现参与了辣椒耐热性的调节，但潜在机制仍知之甚少。在此，PMT6，一种假定的甲基转移酶，最初通过免疫共沉淀（Co-IP）结合 LC/MS 分析被发现与 SWC4 相互作用。这种相互作用进一步通过双分子荧光互补（BiFC）和 Co-IP 分析得到证实，并且 PMT6 进一步被发现赋予 SWC4 甲基化。通过病毒诱导的基因沉默，发现 PMT6 的沉默显著降低了辣椒的基础耐热性和转录，并且显著降低了与染色质激活相关的 H3K9ac、H4K5ac 和 H3K4me3 在 TSS 的富集，先前发现 CaSWC4 对其有正向调控作用。相比之下，PMT6 的过表达显著增强了辣椒植株的基础耐热性。所有这些数据表明，PMT6 作为辣椒耐热性的正调控因子，可能通过甲基化 SWC4 发挥作用。
