A β2-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 Faβ2Tub-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 β2-tubulin gene had different effects on mycelial growth, asexual reproduction and virulence. Faβ2Tub-3 (one of β2-tubulin segments) exhibited a strong silencing efficacy both on β1-tubulin and β2-tubulin genes in F. asiaticum. Faβ2Tub-3 sequence was found to be highly conserved among Fusarium spp., Botrytis cinerea, Magnaporthe oryzae and Colletotrichum truncatum. The Faβ2Tub-3 dsRNA demonstrated a broad-spectrum antifungal activity against these fungi in vitro and on living plant. More importantly, Faβ2Tub-3 dsRNA increased the fungal sensitivity to MBC, while MBC increased the duration of Faβ2Tub-3 dsRNA. Our findings suggest a new anti-fungal agent (Faβ2Tub-3 dsRNA) for plant protection against diverse pathogens and for fungicide reduction.