3 research outputs found
Pectin induced transcriptome of a Rhizoctonia solani strain causing sheath blight disease in rice reveals insights on key genes and RNAi machinery for development of pathogen derived resistance
Key message
RNAi mediated silencing of pectin degrading enzyme of R. solani gives a high level of resistance against sheath blight disease of rice.
Abstract
Rice sheath blight disease caused by Rhizoctonia solani Kuhn (telemorph; Thanatephorus cucumeris) is one of the most devastating fungal diseases which cause severe loss to rice grain production. In the absence of resistant cultivars, the disease is currently managed through fungicides which add to environmental pollution. To explore the potential of utilizing RNA interference (RNAi)-mediated resistance against sheath blight disease, we identified genes encoding proteins and enzymes involved in the RNAi pathway in this fungal pathogen. The RNAi target genes were deciphered by RNAseq analysis of a highly virulent strain of the R. solani grown in pectin medium. Additionally, pectin metabolism associated genes of R. solani were analyzed through transcriptome sequencing of infected rice tissues obtained from six diverse rice cultivars. One of the key candidate gene AG1IA_04727 encoding polygalacturonase (PG), which was observed to be significantly upregulated during infection, was targeted through RNAi to develop disease resistance. Stable expression of PG-RNAi construct in rice showed efficient silencing of AG1IA_04727 and suppression of sheath blight disease. This study highlights important information about the existence of RNAi machinery and key genes of R. solani which can be targeted through RNAi to develop pathogen-derived resistance, thus opening an alternative strategy for developing sheath blight-resistant rice cultivars
Understanding sheath blight resistance in rice: the road behind and the road ahead
Rice sheath blight disease, caused by the basidiomycetous necrotroph Rhizoctonia solani,
became one of the major threats to the rice cultivation worldwide, especially after the adoption
of high-yielding varieties. The pathogen is challenging to manage because of its extensively
broad host range and high genetic variability and also due to the inability to find any satisfactory
level of natural resistance from the available rice germplasm. It is high time to find remedies to
combat the pathogen for reducing rice yield losses and subsequently to minimize the threat to
global food security. The development of genetic resistance is one of the alternative means to
avoid the use of hazardous chemical fungicides. This review mainly focuses on the effort of
better understanding the host–pathogen relationship, finding the gene loci/markers imparting
resistance response and modifying the host genome through transgenic development. The latest
development and trend in the R. solani–rice pathosystem research with gap analysis are
provided