Genome-Wide Identification of <i>Eucalyptus</i> Heat Shock Transcription Factor Family and Their Transcriptional Analysis under Salt and Temperature Stresses

oleh: Tan Yuan, Jianxiang Liang, Jiahao Dai, Xue-Rong Zhou, Wenhai Liao, Mingliang Guo, Mohammad Aslam, Shubin Li, Guangqiu Cao, Shijiang Cao

Format: Article
Diterbitkan: MDPI AG 2022-07-01

Deskripsi

Heat shock transcription factors (HSFs) activate heat shock protein gene expression by binding their promoters in response to heat stress and are considered to be pivotal transcription factors in plants. <i>Eucalyptus</i> is a superior source of fuel and commercial wood. During its growth, high temperature or other abiotic stresses could impact its defense capability and growth. <i>Hsf</i> genes have been cloned and sequenced in many plants, but rarely in <i>Eucalyptus</i>. In this study, we used bioinformatics methods to analyze and identify <i>Eucalyptus</i> <i>Hsf</i> genes, their chromosomal localization and structure. The phylogenetic relationship and conserved domains of their encoded proteins were further analyzed. A total of 36 <i>Hsf</i> genes were identified and authenticated from <i>Eucalyptus</i>, which were scattered across 11 chromosomes. They could be classified into three classes (A, B and C). Additionally, a large number of stress-related cis-regulatory elements were identified in the upstream promoter sequence of <i>HSF</i>, and cis-acting element analysis indicated that the expression of <i>EgHsf</i> may be regulated by plant growth and development, metabolism, hormones and stress responses. The expression profiles of five representative <i>Hsf</i> genes, <i>EgHsf4</i>, <i>EgHsf9</i>, <i>EgHsf13</i>, <i>EgHsf24</i> and <i>EgHsf32</i>, under salt and temperature stresses were examined by qRT-PCR. The results show that the expression pattern of class B genes (<i>EgHsf4</i>, <i>EgHsf24</i> and <i>EgHsf32</i>) was more tolerant to abiotic stresses than that of class A genes (<i>EgHsf9</i> and <i>EgHsf13</i>). However, the expressions of all tested <i>Hsf</i> genes in six tissues were at different levels. Finally, we investigated the network of interplay between genes, and the results suggest that there may be synergistic effects between different <i>Hsf</i> genes in response to abiotic stresses. We conclude that the <i>Hsf</i> gene family played an important role in the growth and developmental processes of <i>Eucalyptus</i> and could be vital for maintaining cell homeostasis against external stresses. This study provides basic information on the members of the <i>Hsf</i> gene family in <i>Eucalyptus</i> and lays the foundation for the functional identification of related genes and the further investigation of their biological functions in plant stress regulation.