Nature Plants (2023)
Small RNA (sRNA)-mediated trans-kingdom RNA interference (RNAi) between host and pathogen has been demonstrated and utilized. However, interspecies RNAi in rhizospheric microorganisms remains elusive. In this study, we developed a microbe-induced gene silencing (MIGS) technology by using a rhizospheric beneficial fungus, Trichoderma harzianum
, to exploit an RNAi engineering microbe and two soil-borne pathogenic fungi, Verticillium dahliae
and Fusarium oxysporum
, as RNAi recipients. We first detected the feasibility of MIGS in inducing GFP silencing in V. dahliae
. Then by targeting a fungal essential gene, we further demonstrated the effectiveness of MIGS in inhibiting fungal growth and protecting dicotyledon cotton and monocotyledon rice plants against V. dahliae
and F. oxysporum
. We also showed steerable MIGS specificity based on a selected target sequence. Our data verify interspecies RNAi in rhizospheric fungi and the potential application of MIGS in crop protection. In addition, the in situ propagation of a rhizospheric beneficial microbe would be optimal in ensuring the stability and sustainability of sRNAs, avoiding the use of nanomaterials to carry chemically synthetic sRNAs. Our finding reveals that exploiting MIGS-based biofungicides would offer straightforward design and implementation, without the need of host genetic modification, in crop protection against phytopathogens.