Botrytis cinereasmall RNAs are associated with tomato AGO1 and silence tomato defense-related target genes supporting cross-kingdom RNAi

Cross-kingdom or cross-species RNA interference (RNAi) is broadly present in many interacting systems between microbes/parasites and their plant and animal hosts. A recent study by Qin et al . (2022) performed correlation analysis using global sRNA- and mRNA-deep sequencing data of cultured B. cinerea and B. cinerea -infected tomato leaves and claimed that cross-kingdom RNAi may not occur in B. cinerea –tomato interaction (Qin et al ., 2022). Here, we use experimental evidence and additional bioinformatics analysis of the datasets produced by Qin et al . (2022) to identify the key reasons why a discrepancy between the conclusion of Qin et al. 2022 and previously published findings occurred. We also provided additional experimental evidence to support the presence of cross-kingdom RNAi between tomato and B. cinerea . We believe it is important to clarify the basic concept and mechanism of cross-kingdom/cross-species sRNA trafficking and illustrate proper bioinformatics analyses in this regard for all the scientists and researchers in this field.