AUTHOR=Ge Wenjie , Lv Mingcan , Feng Hui , Wang Xinlei , Zhang Bo , Li Ken , Zhang Jing , Zou Jiawei , Ji Ruiqin 

TITLE=Analysis of the role of BrRPP1 gene in Chinese cabbage infected by Plasmodiophora brassicae

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1082395

DOI=10.3389/fpls.2023.1082395

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>The clubroot disease caused by <italic>Plasmodiophora brassicae</italic> (<italic>P. brassicae</italic>) poses a serious threat to the economic value of cruciferous crops, which is a serious problem to be solved worldwide. Some resistance genes to clubroot disease in <italic>Brassica rapa</italic> L. ssp <italic>pekinensis</italic> cause by <italic>P. brassicae</italic> have been located on different chromosomes. Among them, <italic>Rcr1</italic> and <italic>Rcr2</italic> were mapped to the common candidate gene <italic>Bra019410</italic>, but its resistance mechanism is not clear yet.</p></sec><sec><title>Methods</title><p>In this experiment, the differences of <italic>BrRPP1</italic> between the resistant and susceptible material of Chinese cabbage were analyzed by gene cloning and qRT-PCR. The gene function was verified by Arabidopsis homologous mutants. The expression site of <italic>BrRPP1</italic> gene in cells was analyzed by subcellular localization. Finally, the candidate interaction protein of <italic>BrRPP1</italic> was screened by yeast two-hybrid library.</p></sec><sec><title>Results</title><p>The results showed that the cDNA sequence, upstream promoter sequence and expression level of <italic>BrRPP1</italic> were quite different between the resistant and susceptible material. The resistance investigation found that the Arabidopsis mutant <italic>rpp1</italic> was more susceptible to clubroot disease than the wild type, which suggested that the deletion of rpp1 reduces resistance of plant to clubroot disease. Subcellular location analysis confirmed that <italic>BrRPP1</italic> was located in the nucleus. The interaction proteins of <italic>BrRPP1</italic> screened from cDNA Yeast Library by yeast two-hybrid are mainly related to photosynthesis, cell wall modification, jasmonic acid signal transduction and programmed cell death.</p></sec><sec><title>Discussion</title><p><italic>BrRPP1</italic> gene contains TIR-NBS-LRR domain and belongs to R gene. The cDNA and promoter sequence of BrRPP1 in resistant varieties was different from that in susceptible varieties led to the significant difference of the gene expression of <italic>BrRPP1</italic> between the resistant varieties and the susceptible varieties. The high expression of <italic>BrRPP1</italic> gene in resistant varieties enhanced the resistance of Chinese cabbage to <italic>P. brassicae</italic>, and the interaction proteins of <italic>BrRPP1</italic> are mainly related to photosynthesis, cell wall modification, jasmonic acid signal transduction and programmed cell death. These results provide important clues for understanding the mechanism of BrRPP1 in the resistance of B. rapa to <italic>P. brassicae</italic>.</p></sec>