Twilight, a Novel Circadian-Regulated Gene, Integrates Phototropism with Nutrient and Redox Homeostasis during Fungal Development

PLoS Pathogens

Ziwei Qu¹  Naweed I. Naqvi²  Yi Zhen Deng² 

[1] Guangdong Province Key Laboratory of Microbial Signals and Disease Control, College of Agronomy, South China Agricultural University, Guangzhou, China;Temasek Life Sciences Laboratory, Department of Biological Sciences, National University of Singapore, Singapore

关键词: Phototropism;    Phosphorylation;    Rice blast fungus;    Fungal pathogens;    Circadian rhythms;    Transcriptional control;    Mycelium;    Homeostasis;   

DOI  :  10.1371/journal.ppat.1004972

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Phototropic regulation of circadian clock is important for environmental adaptation, organismal growth and differentiation. Light plays a critical role in fungal development and virulence. However, it is unclear what governs the intracellular metabolic response to such dark-light rhythms in fungi. Here, we describe a novel circadian-regulated Twilight (TWL) function essential for phototropic induction of asexual development and pathogenesis in the rice-blast fungus Magnaporthe oryzae. The TWL transcript oscillates during circadian cycles and peaks at subjective twilight. GFP-Twl remains acetylated and cytosolic in the dark, whereas light-induced phosphorylation (by the carbon sensor Snf1 kinase) drives it into the nucleus. The mRNA level of the transcription/repair factor TFB5, was significantly down regulated in the twl∆ mutant. Overexpression of TFB5 significantly suppressed the conidiation defects in the twl∆ mutant. Furthermore, Tfb5-GFP translocates to the nucleus during the phototropic response and under redox stress, while it failed to do so in the twl∆ mutant. Thus, we provide mechanistic insight into Twl-based regulation of nutrient and redox homeostasis in response to light during pathogen adaptation to the host milieu in the rice blast pathosystem.

【 授权许可】

CC BY