Genome-Wide Identification and Analysis of the WRKY Gene Family in Asparagus officinalis

Abstract

In recent years, the related research of the <i>WRKY</i> gene family has been gradually promoted, which is mainly reflected in the aspects of environmental stress and hormone response. However, to make the study of the <i>WRKY</i> gene family more complete, we also need to focus on the whole-genome analysis and identification of the family. In previous studies, the whole <i>WRKY</i> gene family of <i>Arabidopsis</i>, legumes and other plants has been thoroughly studied. However, since the publication of <i>Asparagus officinalis</i> genome-wide data, there has never been an analysis of the whole <i>WRKY</i> gene family. To understand more broadly the function of the <i>WRKY</i> gene family, the whole genome and salt stress transcriptome data of asparagus were used for comprehensive analysis in this study, including <i>WRKY</i> gene family identification, phylogenetic tree construction, analysis of conserved mods and gene domains, extraction of cis-acting elements, intron/exon analysis, species collinearity analysis, and <i>WRKY</i> expression analysis under salt stress. The results showed that a total of 70 genes were selected and randomly distributed on 10 chromosomes and one undefined chromosome. According to the functional classification of <i>Arabidopsis thaliana</i>, the <i>WRKY</i> family of asparagus was divided into 11 subgroups (C1-C9, U1, U2). It is worth considering that the distribution rules of gene-conserved motifs, gene domains and introns/exons in the same subfamily are similar, which suggests that genes in the same subfamily may regulate similar physiological processes. In this study, 11 cis-acting elements of <i>WRKY</i> family were selected, among which auxin, gibberellin, abscisic acid, salicylic acid and other hormone-regulated induction elements were involved. In addition, environmental stress (such as drought stress and low-temperature response) also accounted for a large proportion. Interestingly, we analyzed a total of two tandem duplicate genes and 13 segmental duplication genes, suggesting that this is related to the amplification of the <i>WRKY</i> gene family. Transcriptome data analysis showed that <i>WRKY</i> family genes could regulate plant growth and development by up-regulating and down-regulating gene expression under salt stress. Volcanic maps showed that 3 and 15 <i>AoWRKY</i> genes were significantly up-regulated or down-regulated in NI&NI+S and AMF&AMF+S, respectively. These results provide a new way to analyze the evolution and function of the <i>WRKY</i> gene family, and can provide a reference for the production and research of asparagus.