AUTHOR=Jiang Lan , Chen Yu , Bi De , Cao Yunpeng , Tong Jiucui 

TITLE=Deciphering Evolutionary Dynamics of WRKY I Genes in Rosaceae Species

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2021.801490

DOI=10.3389/fevo.2021.801490

ISSN=2296-701X

ABSTRACT=<p>WRKY transcription factors participate in various regulation processes at different developmental stages in higher plants. Here, 98 <italic>WRKY I</italic> genes were identified in seven Rosaceae species. The <italic>WRKY I</italic> genes are highly enriched in some subgroups and are selectively expanded in Chinese pear [<italic>Pyrus bretschneideri</italic> (<italic>P. bretschneideri</italic>)] and apple [<italic>Malus domestica</italic> (<italic>M. domestica</italic>)]. By searching for intra-species gene microsynteny, we found the majority of chromosomal segments for WRKY I-containing segments in both <italic>P. bretschneideri</italic> and <italic>M. domestica</italic> genomes, while paired segments were hardly identified in the other five genomes. Furthermore, we analyzed the environmental selection pressure of duplicated <italic>WRKY I</italic> gene pairs, which indicated that the strong purifying selection for WRKY domains may contribute to the stability of its structure and function. The expression patterns of duplication <italic>PbWRKY</italic> genes revealed that functional redundancy for some of these genes was derived from common ancestry and neo-functionalization or sub-functionalization for some of them. This study traces the evolution of <italic>WRKY I</italic> genes in Rosaceae genomes and lays the foundation for functional studies of these genes in the future. Our results also show that the rates of gene loss and gain in different Rosaceae genomes are far from equilibrium.</p>