Host-Induced Gene Silencing of MoAP1 Confers Broad-Spectrum Resistance to Magnaporthe oryzae

Abstract

Rice blast caused by Magnaporthe oryzae ( M. oryzae ) is a major threat to global rice production. In recent years, small interference RNAs (siRNAs) and host-induced gene silencing (HIGS) has been shown to be new strategies for the development of transgenic plants to control fungal diseases and proved a useful tool to study gene function in pathogens. We here tested whether in vitro feeding artificial siRNAs (asiRNAs) could compromise M. oryza e virulence and in vivo HIGS technique could improve rice blast resistance. Our data revealed that silencing of M. oryzae MoAP1 by feeding asiRNAs targeting MoAP1 (i.e., asiR1245, asiR1362, and asiR1115) resulted in inhibited fungal growth, abnormal spores, and decreased pathogenicity. Among the asiRNAs, asiR1115 was the most inhibitory toward the rice blast fungus. Conversely, the asiRNAs targeting three other genes (i.e., MoSSADH , MoACT , and MoSOM1 ) had no effect on fungal growth. Transgenic rice plants expressing RNA hairpins targeting MoAP1 exhibited improved resistance to 11 tested M. oryzae strains. Confocal microscopy also revealed profoundly restricted appressoria and mycelia in rice blast-infected transgenic rice plants. Our results demonstrate that in vitro asiRNA and in vivo HIGS were useful protection approaches that may be valuable to enhance rice blast resistance.

Transcription factor control of virulence in phytopathogenic fungi

“…tritici as well as V. dahliae Sge1 (Song & Thomma, 2018; Zhu et al., 2018). TFs continue to be explored as effective targets through gene silencing measures (Guo et al., 2019; Sang & Kim, 2019). TFs would also seem to be good targets for chemical intervention, which must be safe for nontarget organisms including the host plants, animals, humans, and beneficial microbes such as mycorrhizal fungi to be commercially viable (Bahn, 2015; Tietjen & Schreier, 2013).…”

Robust Survival-Based RNA Interference of Gene Families Using in Tandem Silencing of Adenine Phosphoribosyltransferase

“…Together, APTi-based silencing efficacy far surpasses other dsRNA-based methods (Vidali et al, 2007;Vidali et al, 2010;Nakaoka et al, 2012;Guo et al, 2019), is comparable to silencing efficiencies for optimized amiRNAs (Zhang et al, 2018), and simplifies downstream analysis for functional genomics.…”

CcPmk1 is a regulator of pathogenicity in Cytospora chrysosperma and can be used as a potential target for disease control

“…Therefore, RNAi can potentially be developed as an efficient genetic strategy against pathogens for pesticide-free disease control in plants by targeting crucial pathogenicity-inducing genes of phytopathogens, which is known as host-induced gene silencing (HIGS) (Nowara et al, 2010;Song & Thomma, 2018). Recently, attempts at HIGS in plant diseases control have emerged across many kinds of phytopathogens, such as Puccinia spp., V. dahliae, M. oryzae, Blumeria graminis, Phytophthora infestans, and Fusarium graminearum (Guo et al, 2019;Panwar et al, 2018;Qi et al, ,2018Qi et al, , , 2019Sanju et al, 2015;Song & Thomma, 2018;Xu et al, 2018;Zhang et al, 2016). Remarkably, the Pmk1 homology in P. triticina has been used as a target for leaf rust disease control; transgenic wheat harbouring a Pmk1-RNAi construct shows significant resistance to the disease (Panwar et al, 2018).…”