Genes expressed during early stages of rice infection with the rice blast fungusMagnaporthe grisea

Abstract

summary A system-wide approach was adopted to further elucidate mechanisms regulating disease outcome between rice and the fungal pathogen Magnaporthe grisea. First, a cDNA library was constructed from M. grisea infected rice at 48 h post-inoculation. The 5' end-sequencing of 619 randomly selected clones revealed 359 expressed sequence tags (ESTs) that had not previously been described. A total of 124 from 260 ESTs with high and moderate similarity scores, based on BlastX, were organized into categories according to their putative function. The largest category of sequences (21%) contained stress or defence response genes. Eleven per cent of identified ESTs were redundant. In a second approach, differential hybridization analysis of the cDNA library using high-density filters resulted in the identification of novel genes and previously characterized M. grisea genes, including several that had previously been implicated in the infection process. A survey of up-regulated cDNA clones revealed clone 29003, which corresponded to the rice peroxidase POX22.3. This gene is known to be expressed in rice upon infection with Xanthomonas oryzae pv. oryzae, the bacterial blight pathogen. Importantly, this approach demonstrates the utility of gene discovery, through ESTs, for revealing novel genes in addition to those previously characterized as being potentially implicated in host-pathogen interactions.

Large-Scale Gene Discovery in the Oomycete Phytophthora infestans Reveals Likely Components of Phytopathogenicity Shared with True Fungi

“…SwissProt, GenBank, and Pfam databases were searched at either Syngenta Biotechnology, Inc, Research Triangle Park, NC, U.S.A.; Syngenta Jealots Hill International Research Centre, Bracknell, Berkshire, UK; or the University of CaliforniaRiverside, U.S.A. The FHI database was complied from 4,838 ESTs from wheat spikes infected with F. graminarium (BM134271-138704, BM140307-140614, and BM259010-259098) (Kruger et al 2002), 4,908 ESTs from germinating conidia of Blumeria graminis and barley infected with that species (Thomas et al 2001); 1,168 ESTs from rice infected with M. grisea (AW154962-155632 and AW069892-070183) (Kim et al 2001;Rauyaree et al 2001), 1,148 ESTs from pine infected with Heterobasidium annosum (BM346837-347258) (Karlsson et al 2003), and 1,156 ESTs from wheat infected with Mycosphaerella graminicola (AW067761-067765 and AW179955-181107). The FP database of validated genes involved in fungus-plant pathogen interaction was compiled from the literature (Idnurm and Howlett 2001).…”

Interaction Transcriptome Analysis Identifies Magnaporthe oryzae BAS1-4 as Biotrophy-Associated Secreted Proteins in Rice Blast Disease

“…Microarray analyses have compared gene expression in germlings growing on inductive surfaces (promoting appressorium formation) and noninductive surfaces (Oh et al, 2008) and gene expression in mycelium growing in nitrogen-rich and nitrogen-deficient media (Donofrio et al, 2006). In planta expression analyses performed following development of macroscopic symptoms identified both fungal and rice genes expressed in planta (Kim et al, 2001;Rauyaree et al, 2001;Matsumura et al, 2003). However, infected tissue with visible symptoms probably included filamentous necrotrophic hyphae in addition to IH (Berruyer et al, 2006).…”

Comparison of gene expression in trap cells and vegetative hyphae of the nematophagous fungus Monacrosporium haptotylum

“…during appressoria formation in Ma. grisea (Rauyaree et al, 2004). Several such genes, including cyclophilins, peptidylprolyl cis-trans isomerases, metallothionein and thioredoxins, appear to be differentially expressed in the knobs of M. haptotylum (Tables 4 and 6).…”