RNA-based disease control as a complementary measure to fight Fusarium fungi through silencing of the azole target Cytochrome P450 Lanosterol C-14 \u03b1-Demethylase

Aline Koch,Elke Stein,Karl-Heinz Kogel

doi:10.1007/s10658-018-1518-4

Abstract

RNA-based disease control has shown great potential for controlling pest and diseases in crop plants. While delivery of inhibitory noncoding double-stranded (ds)RNA by transgenic expression is a promising concept, it requires the generation of transgenic crop plants, which may cause substantial delay for application strategies depending on the transformability and genetic stability of the crop plant species. Focusing on agronomic important barley - Fusarium spec. pathosystems, we have sought for alternative strategies to apply dsRNAs for fungal control. Recently, we have demonstrated that a spray application of a long noncoding dsRNA termed CYP3RNA, which targets the three fungal Cytochrome P450 lanosterol C-14α-demethylase genes FgCYP51A, FgCYP51B, and FgCYP51C, inhibits Fusarium graminearum (Fg) on barley leaves (Koch et al., PLoS Pathogens, 12, e1005901, 2016). Here we show that another Fusarium species, F. culmorum (Fc), also is sensitive to CYP51-derived dsRNAs. Treating Fc with various dsRNAs targeting the genes FcCYP51A, FcCYP51B and FcCYP51C was destructive to the fungus and resulted in growth retardation in in vitro cultures. We discuss important consequences of this finding on future RNA-based disease control strategies. Given the ease of design, high specificity, and applicability to diverse pathogens, the use of target-specific dsRNA as an anti-fungal agent offers unprecedented potential for novel plant protection strategies.

Highlights

To meet the increasing food and energy demands of a growing population, it will be necessary to roughly double crop yields worldwide over the 40–50 years despite a changing climate (FAO 2012; FAO 2013)
We addressed the question whether Fusarium species other than Fusarium graminearum (Fg) are sensitive to dsRNA derived from homologous fungal CYP51 genes
We used custommade dsRNAs deduced from the F. culmorum (Fc) genes FcCYP51A (Fc-CYPA-I; Fc-CYPA-II), FcCYP51B (Fc-CYPB-I; Fc-CYB-II) and FcCYP51C (Fc-CYPC-I; Fc-CYPCII) (Fig. S1)

Summary

Introduction

To meet the increasing food and energy demands of a growing population, it will be necessary to roughly double crop yields worldwide over the 40–50 years despite a changing climate (FAO 2012; FAO 2013). The ago1–27 mutant is more resistant to the pathogenic ascomycete Verticillium dahliae (Vd), which causes Verticillium wilt disease on many plants, suggesting Vd uses sRNAs to silence host target genes.

Results

Conclusion