Rice blast, caused by the fungal pathogen Magnaporthe oryzae , remains a major constraint to rice productivity. To date, more than 100 blast resistance (R) genes have been mapped and about 50 of them, including alleles and orthologues, have been cloned and functionally characterized. Among these, Pi54 , originally identified in the Tetep rice line, encodes a leucine-rich repeat protein with a small zinc finger domain, conferring durable, broad-spectrum resistance against diverse M. oryzae isolates from different rice-growing regions globally. Expanding the allelic base, Pi54 orthologues, Pi54rh and Pi54of , have been cloned from wild rice species, and allelic diversity has been explored in rice landraces. The rice- M. oryzae system represents a classic gene-for-gene interaction. To validate this hypothesis, we sequenced the complete genome of an M. oryzae isolate avirulent on Pi54 and cloned the AvrPi54 gene. The hypersensitive response obtained from the direct interaction between Pi54 and AvrPi54 proteins confirmed the gene-for-gene relationship. Translationally, the Pi54 gene, identified, cloned, and characterized by our group, has been introgressed into over 40 rice mega-varieties using marker-assisted selection in India and abroad, exemplifying the integration of molecular genetics into breeding pipelines. This review synthesizes current insights into the molecular, functional, and applied aspects of Pi54 -mediated blast resistance, highlighting its pivotal role in the ongoing ‘Silent Revolution’ in rice breeding.
Sharma et al. (Fri,) studied this question.