In a paper recently published in BMC Evolutionary Biology, an international team of scientists describes how evasion of host immunity by a clonal variant of the potato blight pathogen Phytophthora infestans is associated with variation in gene expression without any apparent underlying genetic changes. According to senior authors of the study, Vivianne G.A.A. Vleeshouwers, Hannele Lindqvist-Kreuze and Sophien Kamoun, They studied two different races of the Irish potato famine pathogen, and we discovered that the difference invirulence between these races could not be ascribed to a genetic difference but rather to a difference in the expression of the underlying virulence gene. “This adds to our knowledge of how this important scourge on world agriculture evolves to evade plant immunity,” the researchers say.
“…there are several examples of potato cultivars that were initially resistant to late blight when farmers started to grow them, but succumbed to the disease a few years later. The ability to switch on and off virulence genes such as we found in this research may partly explain why the pathogen is so effective at overcoming the plants defense barriers.” Read more