Magnaporthe griseaInfection Triggers RNA Variation and Antisense Transcript Expression in Rice

Abstract

Rice blast disease, caused by the fungal pathogen Magnaporthe grisea, is an excellent model system to study plant-fungal interactions and host defense responses. In this study, comprehensive analysis of the rice (Oryza sativa) transcriptome after M. grisea infection was conducted using robust-long serial analysis of gene expression. A total of 83,382 distinct 21-bp robust-long serial analysis of gene expression tags were identified from 627,262 individual tags isolated from the resistant (R), susceptible (S), and control (C) libraries. Sequence analysis revealed that the tags in the R and S libraries had a significant reduced matching rate to the rice genomic and expressed sequences in comparison to the C library. The high level of one-nucleotide mismatches of the R and S library tags was due to nucleotide conversions. The A-to-G and U-to-C nucleotide conversions were the most predominant types, which were induced in the M. grisea-infected plants. Reverse transcription-polymerase chain reaction analysis showed that expression of the adenine deaminase and cytidine deaminase genes was highly induced after inoculation. In addition, many antisense transcripts were induced in infected plants and expression of four antisense transcripts was confirmed by strand-specific reverse transcription-polymerase chain reaction. These results demonstrate that there is a series of dynamic and complex transcript modifications and changes in the rice transcriptome at the M. grisea early infection stages.

RL-SAGE and microarray analysis of the rice transcriptome after Rhizoctonia solani infection

“…It is noteworthy that many antisense transcripts were identiWed in the R.sonali-infected RL-SAGE library in this study, which is consistent with the Wnding from the M. grisea RL-SAGE libraries (Gowda et al 2007). The expression of four selected antisene transcripts after M. grisea infection was conWrmed using strand-speciWc RT-PCR.…”

Germin and Germin-like Proteins: Evolution, Structure, and Function

“…The results suggest that OxO is a downstream element in the disease resistance signal cascade mediated by OSK3 protein kinase in rice. An interesting study that demonstrates the complexity of transcript variation, including GLP genes, in response to rice blast infection is that published by Gowda et al (2007). They exploited the power of SAGE technology (see above) and identified a high frequency of A-to-G and U-to-C nucleotide conversions in transcripts, as well as many antisense transcripts, in the M. grisea-infected plants.…”

Transcriptional Profiling of Rice Early Response to Magnaporthe oryzae Identified OsWRKYs as Important Regulators in Rice Blast Resistance

“…Transgenic plants overexpressing OsWRKY13 , OsWRKY31 , OsWRKY45 , and OsWRKY53 showed enhanced resistance to M. oryzae , indicating their important roles in rice blast resistance [17]–[21]. Large-scale approaches have also been used to study rice early response to M. oryzae , including EST sequencing [22], robust-long serial analysis of gene expression [23], proteomics [24], [25], and microarrays [26]. A number of genes potentially involved in rice blast resistance were identified from these studies.…”