Glycogen Metabolic Genes Are Involved in Trehalose-6-Phosphate Synthase-Mediated Regulation of Pathogenicity by the Rice Blast Fungus Magnaporthe oryzae

PLoS Pathogens

Richard A. Wilson¹  Michael J. Kershaw¹  Zheng-Yi Wang¹  Muhammad Badaruddin¹  Lucy J. Holcombe¹  Nicholas J. Talbot¹ 

[1] School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom

关键词: Glycogens;    Appressoria;    Rice blast fungus;    Rice;    Gene expression;    Saccharomyces cerevisiae;    Phosphorylases;    Polymerase chain reaction;   

DOI  :  10.1371/journal.ppat.1003604

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The filamentous fungus Magnaporthe oryzae is the causal agent of rice blast disease. Here we show that glycogen metabolic genes play an important role in plant infection by M. oryzae. Targeted deletion of AGL1 and GPH1, which encode amyloglucosidase and glycogen phosphorylase, respectively, prevented mobilisation of glycogen stores during appressorium development and caused a significant reduction in the ability of M. oryzae to cause rice blast disease. By contrast, targeted mutation of GSN1, which encodes glycogen synthase, significantly reduced the synthesis of intracellular glycogen, but had no effect on fungal pathogenicity. We found that loss of AGL1 and GPH1 led to a reduction in expression of TPS1 and TPS3, which encode components of the trehalose-6-phosphate synthase complex, that acts as a genetic switch in M. oryzae. Tps1 responds to glucose-6-phosphate levels and the balance of NADP/NADPH to regulate virulence-associated gene expression, in association with Nmr transcriptional inhibitors. We show that deletion of the NMR3 transcriptional inhibitor gene partially restores virulence to a Δagl1Δgph1 mutant, suggesting that glycogen metabolic genes are necessary for operation of the NADPH-dependent genetic switch in M. oryzae.

【 授权许可】

CC BY