Transcriptome analysis of the rice response to blast fungus identified
core genes involved in immunity
Abstract
Rice blast disease caused by the filamentous Ascomycetous fungus
Magnaporthe oryzae is a major threat to rice production
worldwide. The mechanisms underlying rice resistance to M. oryzae, such
as transcriptional reprogramming and signaling networks, remain elusive.
In this study, we carried out an in-depth comparative transcriptome
study on the susceptible and resistant rice cultivar in response to
M. oryzae. Our analysis highlighted that a rapid, high-amplitude
transcriptional reprogramming was important for rice defense against
blast fungus. The ribosome- and protein translation-related genes were
significantly enriched in differentially expressed genes (DEGs) at 12
hpi in both cultivars, indicating that the protein translation machinery
is regulated in the activation of immunity in rice. Furthermore, we
identified a core set of genes that are involved in the rice response to
biotic as well as to abiotic stress. More importantly, among the core
genes, we demonstrated that the metallothionein OsMT1a and
OsMT1b genes positively while a peroxidase gene Perox4
negatively regulated rice resistance to M. oryzae. Our study
provides novel insight into transcriptional reprogramming and a valuable
resource for functional studies on rice immune signaling components in
resistance to blast disease.