Genome-Wide Characterization of WRKY Transcription Factors Revealed Gene Duplication and Diversification in Populations of Wild to Domesticated Barley

• Main Authors: Jinhong Kan, Guangqi Gao, Qiang He, Qian Gao, Congcong Jiang, Sunny Ahmar, Jun Liu, Jing Zhang, Ping Yang
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: International Journal of Molecular Sciences
• Subjects: barley; WRKY transcription factors; diversity; domestication; adaptation
• Online Access: https://www.mdpi.com/1422-0067/22/10/5354

The WRKY transcription factors (WRKYs) are known for their crucial roles in biotic and abiotic stress responses, and developmental and physiological processes. In barley, early studies revealed their importance, whereas their diversity at the population scale remains hardly estimated. In this study, 98 <i>HsWRKYs</i> and 103 <i>HvWRKYs</i> have been identified from the reference genome of wild and cultivated barley, respectively. The tandem duplication and segmental duplication events from the cultivated barley were observed. By taking advantage of early released exome-captured sequencing datasets in 90 wild barley accessions and 137 landraces, the diversity analysis uncovered synonymous and non-synonymous variants instead of loss-of-function mutations that had occurred at all <i>WRKYs</i>. For majority of <i>WRKYs</i>, the haplotype and nucleotide diversity both decreased in cultivated barley relative to the wild population. Five <i>WRKYs</i> were detected to have undergone selection, among which haplotypes of <i>WRKY9</i> were enriched, correlating with the geographic collection sites. Collectively, profiting from the state-of-the-art barley genomic resources, this work represented the characterization and diversity of barley WRKY transcription factors, shedding light on future deciphering of their roles in barley domestication and adaptation.