M. oryzae

not annotated - annotated - LINNAEUS only

21600998

The cell cycle gene MoCDC15 regulates hyphal growth, asexual development and plant infection in the rice blast pathogen Magnaporthe oryzae.

Rice blast, caused by the pathogen Magnaporthe oryzae, is a serious hindrance to rice production and has emerged as an important model for the characterization of molecular mechanisms relevant to pathogenic development in plants. Similar to other pathogenic fungi, conidiation plays a central role in initiation of M.oryzae infection and spread over a large area. However, relatively little is known regarding the molecular mechanisms that underlie conidiation in M. oryzae. To better characterize these mechanisms, we identified a conidiation-defective mutant, ATMT0225B6 (MoCDC15(T-DNA)), in which a T-DNA insertion disrupted a gene that encodes a homolog of fission yeast cdc15, and generated a second strain containing a disruption in the same allele (DeltaMoCDC15(T-DNA)). The cdc15 gene has been shown to act as a coordinator of the cell cycle in yeast. Functional analysis of the MoCDC15(T-DNA) and DeltaMoCDC15(T-DNA) mutants revealed that MoCDC15 is required for conidiation, preinfection development and pathogenicity in M. oryzae. Conidia from these mutants were viable, but failed to adhere to hydrophobic surface, a crucial step required for subsequent pathogenic development. All phenotypic defects observed in mutants were rescued in a strain complemented with wild type MoCDC15. Together, these data indicate that MoCDC15 functions as a coordinator of several biological processes important for pathogenic development in M. oryzae.

21241815

Genetic and molecular characterization of a blue light photoreceptor MGWC-1 in Magnaporth oryzae.

Three key factors involved in successful plant disease development include the presence of a susceptible host, a virulent pathogen, and a disease-conducive environment. Our understanding of how environmental factors influence disease-conducive or disease-suppressive conditions, and how a pathogen advantageously capitalizes on them, is quite limited. Utilizing the model pathosystem Magnaporthe oryzae-Oryza sativa, we found a significant light-dependent disease suppression. Our genetic data suggest that the blue-light receptor MGWC-1 in M. oryzae is involved in light-dependent disease suppression during the dark-phase (disease-conducive light condition) immediately after pathogen-host contact. Sensing "darkness" is accomplished by MGWC-1, a blue-light receptor in M. oryzae. To explore the potential molecular mechanisms of light-dependent disease suppression we performed a genome-wide microarray experiment and identified several groups of gene families that are differentially regulated during the light-to-dark transition. Our genetic and molecular data provide insights into how a fungal pathogen utilizes ambient light signals for successful disease development.