Abstract: The histone deacetylase (HDAC) gene encodes a class of proteins associated with histone deacetylation and is related to growth, development, and stress response. In this study, we conducted a genome-wide identification and bioinformatics analysis of the Eucalyptus grandis HDAC family members and analyzed the expression patterns of the EgHDAC family in the young leaves, mature leaves, stems, roots, flowers, xylem, phloem, and cambium based on transcriptome data. The results showed that the EgHDAC family could be divided into the RPD3/HDA1, HD2, and SIR2 subfamilies, comprising a total of 15 members, all of which are hydrophilic proteins. Subcellular localization prediction mainly located these proteins in the nucleus and cytoplasm. The promoter sequences of EgHDACs contained many elements responsive to light, hormones, stress, and plant growth. The E. grandis HDAC family genes EgHDT1 and EgHDA2/4/7/8/11 were highly expressed in the young leaves, mature leaves, stems, roots, flowers, xylem, phloem, and cambium tissues, while EgHDA5 was highly expressed only in the leaves. Under treatments with jasmonic acid, salicylic acid, and salt stress, EgHDT1, EgHDA4, and EgHDA5 exhibited varying degrees of expression changes. During the course of evolution, EgHDACs have both conservation and specificity, and they are likely involved in the growth and development of E. grandis, as well as responding to jasmonic acid treatment, salicylic acid treatment, and salt stress, thereby demonstrating the ability to adapt to and regulate the environment.

Key words: HDAC, gene family, genome-wide identification, functional analysis, Eucalyptus grandis

摘要： 基于全基因组序列对巨桉Eucalyptus grandis组蛋白去乙酰化酶(Histone Deacetylase, HDAC)基因家族成员进行鉴定和生物信息学分析，并结合转录组数据分析EgHDAC家族在幼叶、成熟叶、茎、根、花、木质部、韧皮部和形成层的表达情况。结果表明，巨桉HDAC家族可分为RPD3/HDA1、HD2和SIR2亚家族，共含15个成员，均为亲水性蛋白。亚细胞预测定位主要在细胞核和细胞质中。EgHDACs启动子序列包含许多光响应性、激素响应性、应激响应性和植物生长相关元件。EgHDT1和EgHDA2/4/7/8/11在幼叶、成熟叶、茎、根、花、木质部、韧皮部和形成层组织中均高表达，而EgHDA5仅在叶片中高表达。在茉莉酸、水杨酸和盐胁迫处理下，EgHDT1、EgHDA4和EgHDA5均有不同程度的表达。在进化过程中，EgHDACs既具有保守性，又具有特异性，可能参与巨桉的生长发育，并响应茉莉酸处理、水杨酸处理和盐胁迫，体现对环境的适应与调节能力。

关键词: 组蛋白去乙酰化酶, 基因家族, 全基因组鉴定, 功能分析, 巨桉