AUTHOR=Wu Fangli , Huang Yani , Jiang Wenqin , Jin Weibo 

TITLE=Genome-wide identification and validation of tomato-encoded sRNA as the cross-species antifungal factors targeting the virulence genes of Botrytis cinerea

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1072181

DOI=10.3389/fpls.2023.1072181

ISSN=1664-462X

ABSTRACT=<p>Recent evidence shows that small RNAs are transferred from a species to another through cross-species transmission and exhibit biological activities in the receptor. In this study, we focused on tomato-derived sRNAs play a role of defense against <italic>Botrytis cinerea</italic>. Bioinformatics method was firstly employed to identify tomato-encoded sRNAs as the cross-species antifungal factors targeting <italic>B. cinerea</italic> genes. Then the expression levels of some identifed sRNAs were checked in <italic>B. cinerea</italic>-infected plant using qRT-PCR method. Exogenic RNA-induced gene silences analysis were performed to investigate the antifungal roles of the sRNAs, and the target genes in <italic>B. cinerea</italic> of antifungal sRNAs would be confirmed by using co-expression analysis. Results showed that a total of 21 <italic>B.cinerea</italic>-induced sRNAs with high abundance were identified as the cross-kingdom regulator candidates. Among them, three sRNAs containing a miRNA (miR396a-5p) and two siRNA (siR3 and siR14) were selected for experimental validation and bioassay analysis. qRT-PCR confirmed that all of these 3 sRNAs were induced in tomato leaves by <italic>B. cinerea</italic> infection. Correspondingly, 4 virulence genes of B. cinerea respectively targeted by these 3 sRNAs were down-regulated. Bioassay revealed that all of these 3 cross-species sRNAs could inhibit the virulence and spore gemination of <italic>B. cinerea</italic>. Correspondingly, the coding genes of <italic>B. cinerea</italic> targeted by these sRNAs were also down-regulated. Moreover, the virulence inhibition by double strand sRNA was more effective than that by single strand sRNA. The inhibition efficiency of sRNA against <italic>B. cinerea</italic> increased with the increase of its concentration. Our findings provide new evidence into the coevolution of pathogens and host plants, as well as new directions for the use of plant-derived sRNAs to control pathogens.</p>