Abstract Histone methylation mediated by SET Domain Group (SDG) proteins plays an important role in plant response to various abiotic stresses, regulating the expressions of many stress-inducible genes. However, little is known about the SDG genes in Camellia sinensis. In this study, we identified 46 CsSDGs by genome-wide search with the conserved SET domain. Phylogenetic tree, domain composition and gene structure analyses revealed that 46 CsSDGs were classified into five groups, including E(z), ASH1, TRX, SU(VAR) and class VI/VII genes. Furthermore, In silico and qRT-PCR analyses suggested the diverse expression patterns of the 46 CsSDGs in different tissues and in response to various abiotic stresses. To reveal the vital role of CsSDGs in plant responses to abiotic stresses, CsSDG43 was chosen for the functional analysis in hyperosmosis in Arabidopsis. Importantly, CsSDG43 significantly weakened the hyperosmotic tolerance by increasing water loss, reactive oxygen species (ROS) pressure and AHG3 expression in the overexpression lines compared with the wild type of Arabidopsis.

中文翻译：

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山茶SET DOMAIN GROUP基因家族成员特征及非生物胁迫下SDG43基因功能分析

摘要 SET Domain Group (SDG) 蛋白介导的组蛋白甲基化在植物对各种非生物胁迫的响应中起重要作用，调节许多胁迫诱导基因的表达。然而，人们对山茶中的 SDG 基因知之甚少。在这项研究中，我们通过使用保守的 SET 域的全基因组搜索确定了 46 个 CsSDG。系统发育树、域组成和基因结构分析表明，46 个 CsSDGs 分为五组，包括 E(z)、ASH1、TRX、SU(VAR) 和 VI/VII 类基因。此外，计算机模拟和 qRT-PCR 分析表明 46 种 CsSDG 在不同组织中的不同表达模式以及对各种非生物胁迫的响应。为了揭示 CsSDGs 在植物对非生物胁迫响应中的重要作用，选择 CsSDG43 用于拟南芥高渗的功能分析。重要的是，与野生型拟南芥相比，CsSDG43 通过增加过表达系中的失水、活性氧 (ROS) 压力和 AHG3 表达显着削弱了高渗耐受性。