Xi Dengxian, Yin Tuo, Han Peichen, Yang Xiuyao, Zhang Mengjie, Du Chaojin, Zhang Hanyao, Liu Xiaozhen
Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming 650224, China.
Key Laboratory of Biodiversity Conservation in Southwest China, National Forest and Grassland Administration, Southwest Forestry University, Kunming 650224, China.
Curr Issues Mol Biol. 2023 Feb 3;45(2):1250-1271. doi: 10.3390/cimb45020082.
WRKY transcription factors (TFs) play a vital role in plant stress signal transduction and regulate the expression of various stress resistance genes. Sweet orange () accounts for a large proportion of the world's citrus industry, which has high economic value, while is a prime pathogenic causing postharvest rot of oranges. There are few reports on how CsWRKY TFs play their regulatory roles after infects the fruit. In this study, we performed genome-wide identification, classification, phylogenetic and conserved domain analysis of CsWRKY TFs, visualized the structure and chromosomal localization of the encoded genes, explored the expression pattern of each gene under stress by transcriptome data, and made the functional prediction of the related genes. This study provided insight into the characteristics of 47 CsWRKY TFs, which were divided into three subfamilies and eight subgroups. TFs coding genes were unevenly distributed on nine chromosomes. The visualized results of the intron-exon structure and domain are closely related to phylogeny, and widely distributed cis-regulatory elements on each gene played a global regulatory role in gene expression. The expansion of the CSWRKY TFs family was probably facilitated by twenty-one pairs of duplicated genes, and the results of Ka/Ks calculations indicated that this gene family was primarily subjected to purifying selection during evolution. Our transcriptome data showed that 95.7% of genes were involved in the transcriptional regulation of sweet orange in response to infection. We obtained 15 differentially expressed genes and used the reported function of genes as references. They may be involved in defense against and other pathogens, closely related to the stress responses during plant growth and development. Two interesting genes, and , were expressed more than 60 times and could be used as excellent candidate genes in sweet orange genetic improvement. This study offers a theoretical basis for the response of CSWRKY TFs to infection and provides a vital reference for molecular breeding.
WRKY转录因子在植物胁迫信号转导中起着至关重要的作用，并调控各种抗逆基因的表达。甜橙在世界柑橘产业中占很大比例，具有很高的经济价值，而指状青霉是导致橙子采后腐烂的主要病原菌。关于CsWRKY转录因子在指状青霉感染果实后如何发挥调控作用的报道很少。在本研究中，我们对CsWRKY转录因子进行了全基因组鉴定、分类、系统发育和保守结构域分析，可视化了编码基因的结构和染色体定位，通过转录组数据探索了每个CsWRKY基因在指状青霉胁迫下的表达模式，并对相关基因进行了功能预测。本研究深入了解了47个CsWRKY转录因子的特征，它们被分为三个亚家族和八个亚组。编码转录因子的基因在九条染色体上分布不均。内含子-外显子结构和结构域的可视化结果与系统发育密切相关，每个基因上广泛分布的顺式调控元件在基因表达中发挥全局调控作用。CsWRKY转录因子家族的扩张可能由21对重复基因推动，Ka/Ks计算结果表明该基因家族在进化过程中主要受到纯化选择。我们的转录组数据显示，95.7%的CsWRKY基因参与了甜橙对指状青霉感染的转录调控。我们获得了15个差异表达基因，并以已报道的指状青霉基因功能为参考。它们可能参与抵御指状青霉和其他病原菌，与植物生长发育过程中的胁迫反应密切相关。两个有趣的基因CsWRKY33和CsWRKY53表达量超过60倍，可作为甜橙遗传改良的优良候选基因。本研究为CsWRKY转录因子对指状青霉感染的响应提供了理论依据，为分子育种提供了重要参考。
