AUTHOR=Li Jian , Lin Keyun , Zhang Shuai , Wu Jian , Fang Yujie , Wang Youping 

TITLE=Genome-Wide Analysis of Myeloblastosis-Related Genes in Brassica napus L. and Positive Modulation of Osmotic Tolerance by BnMRD107

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.678202

DOI=10.3389/fpls.2021.678202

ISSN=1664-462X

ABSTRACT=<p>Myeloblastosis (MYB)-related transcription factors comprise a large subfamily of the MYB family. They play significant roles in plant development and in stress responses. However, MYB-related proteins have not been comprehensively investigated in rapeseed (<italic>Brassica napus</italic> L.). In the present study, a genome-wide analysis of MYB-related transcription factors was performed in rapeseed. We identified 251 <italic>Brassica napus MYB</italic> (BnMYB)-related members, which were divided phylogenetically into five clades. Evolutionary analysis suggested that whole genome duplication and segmental duplication events have played a significant role in the expansion of <italic>BnMYB-related</italic> gene family. Selective pressure of <italic>BnMYB-related</italic> genes was estimated using the <italic>Ka/Ks</italic> ratio, which indicated that <italic>BnMYB-related</italic> genes underwent strong purifying selection during evolution. <italic>In silico</italic> analysis showed that various development-associated, phytohormone-responsive, and stress-related <italic>cis</italic>-acting regulatory elements were enriched in the promoter regions of <italic>BnMYB-related</italic> genes. Furthermore, <italic>MYB-related</italic> genes with tissue or organ-specific, stress-responsive expression patterns were identified in <italic>B. napus</italic> based on temporospatial and abiotic stress expression profiles. Among the stress-responsive <italic>MYB-related</italic> genes, <italic>BnMRD107</italic> was strongly induced by drought stress, and was therefore selected for functional study. Rapeseed seedlings overexpressing <italic>BnMRD107</italic> showed improved resistance to osmotic stress. Our findings not only lay a foundation for further functional characterization of <italic>BnMYB-related</italic> genes, but also provide valuable clues to determine candidate genes for future genetic improvement of <italic>B. napus</italic>.</p>