The Arabidopsis gene RESISTANCE TO POWDERY MILDEW8.1 (RPW8.1) confers
resistance to virulent fungal pathogens. However, the underlying mechanism
remains unclear. Yan Li and a team of researchers from Sichuan Agricultural
University studied the gene by ectopic expression of RPW8.1 in Arabidopsis
and rice. This boosted pattern-triggered immunity (PTI), resulting in
enhanced resistance against different pathogens in both crops.
In Arabidopsis, analysis revealed that ectopic expression of RPW8.1-YFP
upregulated expression of many pathogen-associated molecular pattern
(PAMP-)-inducible genes. The transgenic line exhibited pronounced PTI
responses such as callose deposition, production of reactive oxygen species,
expression of defense-related genes and hypersensitive response such as cell
Hence, the growth of a virulent bacterial pathogen was significantly
inhibited in transgenic lines expressing RPW8.1-YFP. In rice, expression of
RPW8.1-YFP led to enhanced resistance to the blast fungus Pyricularia oryzae
and the bacterial pathogen Xanthomonas oryzae pv. oryzae.
These results suggest a connection between RPW8.1 function and PTI, and
demonstrate the potential of RPW8.1 as a transgene for engineering disease
resistance across crops.