Magnaporthe oryzae

Genomic studies on rice-rice blast fungus interaction in different climatic scenarios

Elevated global temperatures are one key factor of expected climate change. Temperature is also a key factor in both plant disease development (Huang et al. 2005) and resistance response of the host (Huang et al. 2006). Plants depend on their innate immune system to recognize pathogen-associated molecules and trigger an immune response (Jones and Dangl, 2006). Central to this process of recognition and defense response are the disease resistance (R) genes (Jorgensen et al. 2011). However, much of the work on plants points to warmer temperatures being detrimental to R gene mediated resistance (Moerschbacher et al. 1989; Gijzen et al. 1996; Write et al. 2000; Chongo and Bernier, 2000; Huang et al. 2006; Wang et al. 2009). Fortunately, there is some evidence that warmer temperatures are helpful (de Jong et al., 2002; Yan and Chen, 2008; Fu et al., 2009; Webb et al., 2010), and many factors that affect R-gene signaling upstream and downstream of activation have been reported (Eitas and Dangl, 2010; Elmore et al. 2011), some of which are known to respond to variable environments (Shi et al. 2011; Jorgensen et al. 2011). However, knowledge about the genetic factors involved in R-mediated resistance at high temperature in rice-Magnaporthe oryzae interaction is limited.  The aim of our study is to examine the effects of temperature on host resistance in a rice-Magnaporthe oryzae model system. The initial experiment is to resolve how temperature affects rice-Magnaporthe oryzae interaction using a number of rice lines with R genes in two genetic backgrounds. We then carry out further experiments to determine whether the effects of temperature on survival are due to changes in the host resistance by looking at the key physiological changes related to resistance. We measure the effects of temperature on fungal growth within the host. Then we examine the effect of temperature on host defence function, we take an indirect approach and examine levels of gene expression in defence-related genes after pathogen challenge at different temperatures.

(GO 2012/10)