A β-tubulin dsRNA derived from Fusarium asiaticum confers plant resistance to multiple phytopathogens and reduces fungicide resistance.

Crops are attacked by a large number of pathogens which are responsible for an approximately 30% loss in global crop production at pre- and post-harvest levels. In light of the continuing emergence of fungicide resistance, the needs for new agricultural drugs turn out to be much more critical. Here we demonstrated a FaβTub-3 dsRNA derived from Fusarium asiaticum had broad-spectrum antifungal activity against Fusarium spp., Botrytis cinerea, Magnaporthe oryzae and Colletotrichum truncatum, with an additional function of reducing the dosage of carbendazim (MBC) fungicide. RNAi molecules derived from different regions of β-tubulin gene had different effects on mycelial growth, asexual reproduction and virulence. FaβTub-3 (one of β-tubulin segments) exhibited a strong silencing efficacy both on β-tubulin and β-tubulin genes in F. asiaticum. FaβTub-3 sequence was found to be highly conserved among Fusarium spp., Botrytis cinerea, Magnaporthe oryzae and Colletotrichum truncatum. The FaβTub-3 dsRNA demonstrated a broad-spectrum antifungal activity against these fungi in vitro and on living plant. More importantly, FaβTub-3 dsRNA increased the fungal sensitivity to MBC, while MBC increased the duration of FaβTub-3 dsRNA. Our findings suggest a new anti-fungal agent (FaβTub-3 dsRNA) for plant protection against diverse pathogens and for fungicide reduction.