Rice Blast Research Paper

Rice blast, caused by the ascomycete Magnaporthe oryzae (M.oryzae) [1], is a serious rice disease in more than 90 countries across the globe and is considered as devastating threats to rice production worldwide [2]. It is estimated that each year harvest losses caused by rice blast could reach 10 % to 50 % of the global rice yield which is enough to feed about 60 million people [3]. Over the years, the damage caused by M.oryzae has made the development of chemical and genetic treatment in some varieties of rice. Fungicides are used intensively and regularly, however the fungus rapidly develops resistance and finally destroys the crop. For decades, rice breeders always focus on finding sources of resistance to rice blast which has been a constant

Novel approaches for development of more long-lasting resistance in cereals to ever-changing fungal pathogens are desirable. An alternative method is to screen the fungal genes which are identified as being crucial for pathogenicity and target these genes to improve the fungal resistance in host plants. Because of its genetic accessibility of genome sequences for both rice and the fungus, the rice-blast system has been a leading model to study plant–fungal pathogen interactions [4]. In this study, we tend to investigate the feasibility of a novel approach of rice blast control.
RNA-induced gene silencing or RNA interference (RNAi) is a conserved regulatory mechanism of gene expression, in which double-stranded RNA(dsRNA) triggers the degradation of a homologous mRNA, thereby diminishing or abolishing gene expression [5].The RNAi mechanisms have been exploited extensively and have become powerful

Moreover, we optimized the rice BMV-VIGS system previously established by Ding et al. [38] and adapted it to experimental conditions that allows subsequent fungi infection with M.oryzae. Three genes are chosen as targets that had been implicated in pathogenicity: ABC1[40],MAC1[41] and PMK1[42].Our results show that the generation of target M.oryzae gene-specific siRNA molecules in rice treated with BMV silencing vectors which trigger RNA silencing of the corresponding genes in invading and colonizing M.oryzae, ultimately inhibiting the invasion of host cells by the fungus and resulting in disease suppression. We also found that the efficiency of HIGS improves when simultaneously introducing sense and antisense forms of the candidate fungal gene fragments and silencing three fungal pathogenic genes together. The improved understanding will guide the development of effective control measures against fungi. HIGS might be used to control multiple diseases of a given crop because we can silence different genes together from the different