The WRKY transcription factor family in cowpea: Genomic characterization and transcriptomic profiling under root dehydration

• Published in: Gene 2022-05, Vol.823, p.146377-146377, Article 146377
• Main Authors: Matos, Mitalle Karen da Silva, Benko-Iseppon, Ana Maria, Bezerra-Neto, João Pacifico, Ferreira-Neto, José Ribamar Costa, Wang, Yu, Liu, Hai, Pandolfi, Valesca, Amorim, Lidiane Lindinalva Barbosa, Willadino, Lilia, do Vale Amorim, Thialisson Caaci, Kido, Ederson Akio, Vianello, Rosana Pereira, Timko, Michael P., Brasileiro-Vidal, Ana Christina
• Format: Article
• Language: English
• Subjects: Abiotic stress; Alternative Splicing; Amino Acid Motifs; Chromosome Mapping; Differential expression; Drought; Droughts; Gene Expression Profiling - methods; Gene Expression Regulation, Plant; Genomics - methods; Multigene Family; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Roots - genetics; Promoter Regions, Genetic; Protein Domains; qPCR; RNA-Seq; Stress, Physiological; Transcription Factors - chemistry; Transcription Factors - genetics; Vigna - genetics; Vigna unguiculata
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2022.146377

[Display omitted] •55 VuWRKY genes were modulated under root dehydration with 97 splicing variants.•A significant transcriptional response had occurred in the first hours of stress.•The drought-tolerant accession showed an earlier response than the sensitive one.•Cis-regulatory binding motifs to VuWRKY genes reinforce their role under stress.•From the 22 qPCR validated genes, three stood out by significant induction levels. Cowpea [Vigna unguiculata (L.) Walp.] is one of the most tolerant legume crops to drought and salt stresses. WRKY transcription factor (TF) family members stand out among plant transcriptional regulators related to abiotic stress tolerance. However, little information is currently available on the expression of the cowpea WRKY gene family (VuWRKY) in response to water deficit. Thus, we analyzed genomic and transcriptomic data from cowpea to identify VuWRKY members and characterize their structure and transcriptional response under root dehydration stress. Ninety-two complete VuWRKY genes were found in the cowpea genome based on their domain characteristics. They were clustered into three groups: I (15 members), II (58), and III (16), while three genes were unclassified. Domain analysis of the encoded proteins identified four major variants of the conserved heptapeptide motif WRKYGQK. In silico analysis of VuWRKY gene promoters identified eight candidate binding motifs of cis-regulatory elements, regulated mainly by six TF families associated with abiotic stress responses. Ninety-seven VuWRKY modulated splicing variants associated with 55 VuWRKY genes were identified via RNA-Seq analysis available at the Cowpea Genomics Consortium (CpGC) database. qPCR analyses showed that 22 genes are induced under root dehydration, with VuWRKY18, 21, and 75 exhibiting the most significant induction levels. Given their central role in activating signal transduction cascades in abiotic stress response, the data provide a foundation for the targeted modification of specific VuWRKY family members to improve drought tolerance in this important climate-resilient legume in the developing world and beyond.