AUTHOR=Peng Tao , Yuan Yingzhe , Huang Aijun , He Jun , Fu Shimin , Duan Shuo , Yi Long , Yuan Chenyang , Yuan Huizhu , Wang Xuefeng , Zhou Changyong 

TITLE=Interaction between the flagellum of Candidatus Liberibacter asiaticus and the vitellogenin-like protein of Diaphorina citri significantly influences CLas titer

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1119619

DOI=10.3389/fmicb.2023.1119619

ISSN=1664-302X

ABSTRACT=<p>Huanglongbing (HLB) is a global devastating citrus disease that is mainly caused by “<italic>Candidatus</italic> Liberibacter asiaticus” (<italic>C</italic>Las). It is mostly transmitted by the insect Asian citrus psyllid (ACP, <italic>Diaphorina citri</italic>) in a persistent and proliferative manner. <italic>C</italic>Las traverses multiple barriers to complete an infection cycle and is likely involved in multiple interactions with <italic>D. citri</italic>. However, the protein–protein interactions between <italic>C</italic>Las and <italic>D. citri</italic> are largely unknown. Here, we report on a vitellogenin-like protein (Vg_VWD) in <italic>D. citri</italic> that interacts with a <italic>C</italic>Las flagellum (flaA) protein. We found that <italic>Vg_VWD</italic> was upregulated in <italic>C</italic>Las-infected <italic>D. citri.</italic> Silencing of <italic>Vg_VWD</italic> in <italic>D. citri via</italic> RNAi silencing significantly increased the <italic>C</italic>Las titer, suggesting that <italic>Vg_VWD</italic> plays an important role in the <italic>C</italic>Las<italic>–D. citri</italic> interaction. <italic>Agrobacterium</italic>-mediated transient expression assays indicated that Vg_VWD inhibits BAX- and INF1-triggered necrosis and suppresses the callose deposition induced by flaA in <italic>Nicotiana benthamiana</italic>. These findings provide new insights into the molecular interaction between <italic>C</italic>Las and <italic>D. citri</italic>.</p>