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

Abstract

Dendrobium catenatum 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 D. catenatum. In this study, a total of 62 WRKY genes were identified from the D. catenatum 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. DcWRKY 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 DcWRKY22, DcWRKY36 and DcWRKY45 were up-regulated by drought stress. Meanwhile, DcWRKY22 was highly induced by heat in roots, and DcWRKY45 was significantly induced by cold stress in leaves. Furthermore, DcWRKY27 in roots and DcWRKY58 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 WRKY 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 D. catenatum.

Genome-wide identification and expression analysis of WRKY gene family members in red clover (Trifolium pratense L.)

“…Investigating the expression patterns of genes in various tissues is of paramount importance for mining functional genes ( Dutta et al., 2018 ). Research has demonstrated that WRKY genes exhibit expression in one or more tissues, and they are crucial for plant growth and development ( Feng et al., 2022 ; Zhang et al., 2022b ). The evolutionary relationship between CsWRKY7 and AtWRKY7 in Camellia sinensis is closely related, and root elongation was higher in CsWRKY7 than in wild type ( Chen et al., 2019 ).…”

Genome-wide identification of Cymbidium sinense WRKY gene family and the importance of its Group III members in response to abiotic stress

“…Nevertheless, Group III WRKY genes are considered the most vital group in gene family evolution and seemingly play an important role in the adaptation and evolution of plants ( Zhang and Wang, 2005 ; Goel et al, 2016 ; Shan et al, 2021 ; Khan et al, 2022 ). In C. sinense , 11 CsWRKY gene members belonged to Group III, and such a number is fewer than the corresponding number in most other plants, such as 13 in Arabidopsis ( Kalde et al, 2003 ), 28 in rice ( Wang et al, 2015 ), 35 in maize ( Hu et al, 2021 ), 62 in Dendrobium catenatum ( Zhang et al, 2022b ), 57 in Phalaenopsis , and 43 in Apostasia (unpublished). These findings suggested the functional conservation of WRKY genes during orchid evolution.…”

Genome-wide identification of WRKY genes in soybean and functional analysis of GmWRKY162-GmGSL7c in resistance to soybean mosaic virus

“…To explore the regulatory mechanisms of GmWRKYs, 32 types of cis-elements were identi ed in the promoters of GmWRKYs [49,50], which were involved in hormone responses, stress responses, plant growth, and developmental response, and light responses (Fig. 4 and Table S6).…”