AUTHOR=Yuan Guoxin , Zhang Nijing , Zou Yiming , Hao Yaqi , Pan Jiahao , Liu Yongzhao , Zhang Weiguo , Li Beibei 

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

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1289507

DOI=10.3389/fpls.2023.1289507

ISSN=1664-462X

ABSTRACT=<p><italic>Trifolium pratense</italic> is an important legume forage grass and a key component of sustainable livestock development. Serving as an essential component, the <italic>WRKY</italic> gene family, a crucial group of regulatory transcription factors in plants, holds significant importance in their response to abiotic stresses. However, there has been no systematic analysis conducted on the <italic>WRKY</italic> gene family in <italic>Trifolium pratense</italic>. This study conducted a comprehensive genomic characterization of the <italic>WRKY</italic> gene family in <italic>Trifolium pratense</italic>, utilizing the latest genomic data, resulting in the identification of 59 <italic>TpWRKY</italic> genes. Based on their structural features, phylogenetic characteristics, and conserved motif composition, the WRKY proteins were classified into three groups, with group II further subdivided into five subgroups (II-a, II-b, II-c, II-d, and II-e). The majority of the TpWRKYs in a group share a similar structure and motif composition. Intra-group syntenic analysis revealed eight pairs of duplicate segments. The expression patterns of 59 <italic>TpWRKY</italic> genes in roots, stems, leaves, and flowers were examined by analyzing RNA-seq data. The expression of 12 <italic>TpWRKY</italic> genes under drought, low-temperature (4°C), methyl jasmonate (MeJA) and abscisic acid (ABA) stresses was analyzed by RT-qPCR. The findings indicated that <italic>TpWRKY46</italic> was highly induced by drought stress, and <italic>TpWRKY26</italic> and <italic>TpWRKY41</italic> were significantly induced by low temperature stress. In addition, <italic>TpWRKY29</italic> and <italic>TpWRKY36</italic> were greatly induced by MeJA stress treatment, and <italic>TpWRKY17</italic> was significantly upregulated by ABA stress treatment. In this research, we identified and comprehensively analyzed the structural features of the <italic>WRKY</italic> gene family in <italic>T.pratense</italic>, along with determined the possible roles of <italic>WRKY</italic> candidate genes in abiotic stress. These discoveries deepen our understandings of how WRKY transcription factors contribute to species evolution and functional divergence, laying a solid molecular foundation for future exploration and study of stress resistance mechanisms in <italic>T.pratense</italic>.</p>