AUTHOR=Wang Duoduo , Jin Shunda , Chen Zhe , Shan Yue , Li Lei 

TITLE=Genome-wide identification of the pectin methylesterase inhibitor genes in Brassica napus and expression analysis of selected members

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.940284

DOI=10.3389/fpls.2022.940284

ISSN=1664-462X

ABSTRACT=<p>Pectin methylesterase inhibitors (PMEIs) modulate the status of pectin methylesterification by inhibiting the activity of pectin methylesterase (PME). Recent advances indicate PMEIs play an important role in regulating plant cell wall properties and defense responses. In this study, a genome-wide analysis of <italic>PMEI</italic> gene family in <italic>Brassica napus</italic> (<italic>B. napus</italic>) was conducted and the expression patterns of <italic>PMEI</italic> genes in response to <italic>Sclerotinia sclerotiorum</italic> (<italic>S. sclerotiorum</italic>) was investigated. A total of 190 PMEI proteins were identified from the genome of <italic>B. napus</italic>. Chromosomal location, gene structure and properties of the PMEI family were analyzed, and these features were compared with <italic>Arabidopsis thaliana (A. thaliana)</italic>. A total of 123 syntenic ortholog pairs were detected from <italic>BnPMEI</italic> family by synteny analysis. Results showed the expansion of <italic>BnPMEI</italic> genes was likely predominately from whole-genome duplication (WGD) or segmental duplications. Multiple <italic>cis</italic>-elements related to plant growth and development, environmental stress responses, hormone responses were detected in the promoters of <italic>BnPMEI</italic> genes, implying they were regulated by both internal and external factors. Furthermore, expression analysis of transcriptome data combined with quantitative RT-PCR (qRT-PCR) validation identified several candidates that were strongly responsive to <italic>S. sclerotiorum</italic> infection. These <italic>BnPMEI</italic> genes are candidates for manipulation to breed novel and improved genotypes that are more resistant to sclerotinia stem rot (SSR). Extensive interactions were detected among 30 BnPMEI proteins, forming complex protein-protein interaction networks. Besides, 48 BnPMEIs showed interactions with other proteins including a range of cell wall structure-related enzymes. This study provides new insights into the evolution and function of PMEIs in <italic>B. napus</italic> and lays a foundation for breeding novel genotypes for crop improvement.</p>