AUTHOR=Zhang Tingting , Xu Ying , Ding Yadan , Yu Wengang , Wang Jian , Lai Hanggui , Zhou Yang 

TITLE=Identification and Expression Analysis of WRKY Gene Family in Response to Abiotic Stress in Dendrobium catenatum

JOURNAL=Frontiers in Genetics

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.800019

DOI=10.3389/fgene.2022.800019

ISSN=1664-8021

ABSTRACT=<p><italic>Dendrobium catenatum</italic> has become a rare and endangered medicinal plant due to habitat loss in China. As one of the most important and largest transcription factors, WRKY plays a critical role in response to abiotic stresses in plants. However, little is known regarding the functions of the WRKY family in <italic>D. catenatum</italic>. In this study, a total of 62 <italic>WRKY</italic> genes were identified from the <italic>D. catenatum</italic> genome. Phylogenetic analysis revealed that DcWRKY proteins could be divided into three groups, a division supported by the conserved motif compositions and intron/exon structures. <italic>DcWRKY</italic> gene expression and specific responses under drought, heat, cold and salt stresses were analyzed through RNA-seq data and RT-qPCR assay. The results showed that these genes had tissue-specificity and displayed different expression patterns in response to abiotic stresses. The expression levels of <italic>DcWRKY22</italic>, <italic>DcWRKY36</italic> and <italic>DcWRKY45</italic> were up-regulated by drought stress. Meanwhile, <italic>DcWRKY22</italic> was highly induced by heat in roots, and <italic>DcWRKY45</italic> was significantly induced by cold stress in leaves. Furthermore, <italic>DcWRKY27</italic> in roots and <italic>DcWRKY58</italic> in leaves were extremely induced under salt treatment. Finally, we found that all the five genes may function in ABA- and SA-dependent manners. This study identified candidate <italic>WRKY</italic> genes with possible roles in abiotic stress and these findings not only contribute to our understanding of WRKY family genes, but also provide valuable information for stress resistance development in <italic>D. catenatum</italic>.</p>