Key Laboratory of Applied Genetics of Universities in Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Department of Plant Breeding and Genetics, Ghazi University, Dera Ghazi Khan 32200, Pakistan.
Int J Mol Sci. 2022 Jun 10;23(12):6492. doi: 10.3390/ijms23126492.
Proteins with conserved SET domain play a critical role in plant immunity. However, the means of organization and functions of these proteins are unclear, particularly in non-model plants such as pepper ( L.). Herein, we functionally characterized , a member of class II (the ASH1 homologs H3K36) proteins in pepper immunity against and pv DC3000 ( DC3000). The was localized in the nucleus, and its transcript levels were significantly enhanced by inoculation (RSI) and exogenous application of salicylic acid (SA), methyl jasmonate (MeJA), ethephon (ETH), and abscisic acid (ABA). Knockdown of by virus-induced gene silencing (VIGS) compromised peppers' resistance to RSI. Furthermore, silencing of impaired hypersensitive-response (HR)-like cell death response due to RSI and downregulated defense-associated marker genes, including , , and The protein was revealed to affect the promoters of , , and Transiently over-expression of in pepper leaves elicited HR-like cell death and upregulated immunity-related marker genes. To further study the role of in plant defense in vivo, transgenic plants were generated in . Overexpression of in transgenic enhanced innate immunity against DC3000. Furthermore, over-expressing transgenic plants exhibited upregulated transcriptional levels of immunity-associated marker genes, such as , , and . These results collectively confirm the role of as a positive regulator of plant cell death and pepper immunity against bacterial pathogens, which is regulated by signaling synergistically mediated by SA, JA, ET, and ABA.
具有保守 SET 结构域的蛋白质在植物免疫中起着关键作用。然而，这些蛋白质的组织方式和功能尚不清楚，尤其是在非模式植物如辣椒（L.）中。在此，我们对辣椒中 class II（ASH1 同源物 H3K36）蛋白家族成员 进行了功能表征，以抵抗 和 pv DC3000（DC3000）。该蛋白定位于细胞核中，其转录水平在 接种（RSI）和外源施用水杨酸（SA）、茉莉酸甲酯（MeJA）、乙烯利（ETH）和脱落酸（ABA）后显著增强。通过病毒诱导的基因沉默（VIGS）敲低 会削弱辣椒对 RSI 的抗性。此外，沉默 会削弱由于 RSI 引起的类过敏反应（HR）样细胞死亡反应，并下调防御相关标记基因，包括 、 和 。该 蛋白被揭示会影响 、 和 的启动子。在辣椒叶片中瞬时过表达 会引发 HR 样细胞死亡并上调免疫相关标记基因。为了进一步研究 在体内植物防御中的作用，在 中生成了 转基因植物。在转基因 中过表达 增强了对 DC3000 的先天免疫。此外，过表达 的转基因 植物表现出免疫相关标记基因转录水平的上调，如 、 和 。这些结果共同证实了 作为植物细胞死亡和辣椒对细菌病原体免疫的正调节剂的作用，该作用受 SA、JA、ET 和 ABA 协同介导的信号通路调节。
