Comparative Transcriptome Profiling of the Early Response to Magnaporthe oryzae in Durable Resistant vs Susceptible Rice (Oryza sativa L.) Genotypes

Abstract

Durable resistance to blast, the most significant fungal disease of rice, represents an agronomically relevant character. Gigante Vercelli (GV) and Vialone Nano (VN) are two old temperate japonica Italian rice cultivars with contrasting response to blast infection: GV displays durable and broad resistance while VN is highly susceptible. RNA-seq was used to dissect the early molecular processes deployed during the resistance response of GV at 24 h after blast inoculation. Differential gene expression analysis identified 1,070 and 1,484 modulated genes, of which 726 and 699 were up regulated in response to infection in GV and VN, respectively. Gene ontology (GO) enrichment analyses revealed a set of GO terms enriched in both varieties but, despite this commonality, the gene sets contributing to common GO enriched terms were dissimilar. The expression patterns of genes grouped in GV-specific enriched GO terms were examined in detail including at the transcript isoform level. GV exhibited a dramatic up-regulation of genes encoding diterpene phytoalexin biosynthetic enzymes, flavin-containing monooxygenase, class I chitinase and glycosyl hydrolase 17. The sensitivity and high dynamic range of RNA-seq allowed the identification of genes critically involved in conferring GV resistance during the early steps of defence perception-signalling. These included chitin oligosaccharides sensing factors, wall associated kinases, MAPK cascades and WRKY transcription factors. Candidate genes with expression patterns consistent with a potential role as GV-specific functional resistance (R) gene(s) were also identified. This first application of RNA-seq to dissect durable blast resistance supports a crucial role of the prompt induction of a battery of responses including defence-related genes as well as members of gene families involved in signalling and pathogen-related gene expression regulation.

Resistance to neck blast caused by Pyricularia oryzae in Italian rice cultivars

“…Considering that there isn't always a correlation between symptoms observed on leaves and then on panicles and despite the huge amount of study on resistance genes, host-pathogen interaction, selection of resistant cultivar (Dean et al 2005;Jia et al 2000Jia et al , 2009Bagnaresi et al 2012;Campos-Soriano et al 2013;Miah et al 2013;Wu et al 2013) it is still important to confirm in-field the expression of any possible resistance on the basis of the environment and agricultural techniques used. The availability of data about the field resistance is an important tool for researchers, breeders and growers, combining scientific value with impact in applications.…”

Phloem-exudate proteome analysis of response to insect brown plant-hopper in rice

“…There is circumstantial evidence to suggest that RGAP, which is involved in recognizing pathogen-associated molecular patterns and activate signaling pathways that lead to immunity, including generation of ROS and plant defense gene expression (Shimizu et al, 2010). RGAP was induced by rice blast fungus in rice plants (Bagnaresi et al, 2012). It is noteworthy that RGAP abundance increased by approximately a factor of two in the resistant variety following BPH feeding, but was only slightly upregulated in the susceptible variety.…”

The WRKY45-2 WRKY13 WRKY42 Transcriptional Regulatory Cascade Is Required for Rice Resistance to Fungal Pathogen

“…Systematic analyses of WRKY gene expression in rice-pathogen interactions have revealed that many WRKY genes are rapidly induced or repressed upon pathogen infection, suggesting that these WRKY genes may contribute to the regulation of rice response to pathogen infection (Ryu et al, 2006;Bagnaresi et al, 2012;Wei et al, 2013). In addition, 13 rice WRKY genes from 12 loci have been characterized to be involved in rice-pathogen interactions.…”