AUTHOR=Zuo Rong , Xie Meili , Gao Feng , Liu Jie , Tang Minqiang , Cheng Xiaohui , Liu Yueying , Bai Zetao , Liu Shengyi 

TITLE=Genome-wide identification and functional exploration of the legume lectin genes in Brassica napus and their roles in Sclerotinia disease resistance

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.963263

DOI=10.3389/fpls.2022.963263

ISSN=1664-462X

ABSTRACT=<p>As one of the largest classes of lectins, legume lectins have a variety of desirable features such as antibacterial and insecticidal activities as well as anti-abiotic stress ability. The <italic>Sclerotinia</italic> disease (SD) caused by the soil-borne fungus <italic>Sclerotinia sclerotiorum</italic> is a devastating disease affecting most oil crops such as <italic>Brassica napus</italic>. Here, we identified 130 legume lectin (<italic>LegLu</italic>) genes in <italic>B. napus</italic>, which could be phylogenetically classified into seven clusters. The <italic>BnLegLu</italic> gene family has been significantly expanded since the whole-genome duplication (WGD) or segmental duplication. Gene structure and conserved motif analysis suggested that the <italic>BnLegLu</italic> genes were well conserved in each cluster. Moreover, relative to those genes only containing the legume lectin domain in cluster VI–VII, the genes in cluster I–V harbored a transmembrane domain and a kinase domain linked to the legume lectin domain in the C terminus. The expression of most <italic>BnLegLu</italic> genes was relatively low in various tissues. Thirty-five <italic>BnLegLu</italic> genes were responsive to abiotic stress, and 40 <italic>BnLegLu</italic> genes were strongly induced by <italic>S. sclerotiorum</italic>, with a most significant up-regulation of 715-fold, indicating their functional roles in SD resistance. Four <italic>BnLegLu</italic> genes were located in the candidate regions of genome-wide association analysis (GWAS) results which resulted from a worldwide rapeseed population consisting of 324 accessions associated with SD. Among them, the positive role of <italic>BnLegLus-16</italic> in SD resistance was validated by transient expression in tobacco leaves. This study provides important information on <italic>BnLegLu</italic> genes, particularly about their roles in SD resistance, which may help targeted functional research and genetic improvement in the breeding of <italic>B. napus</italic>.</p>