Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

Light Regulation In Magnaporthe oryzae

Kwangwon Lee , Pratibha Singh , Wen-Chuan Chung , Joshua Ash , Tae-Sung Kim , Lisa E. Hang , Sohyun Park

  Department of Plant Pathology, Cornell University, Ithaca NY, 14850, USA

Light is one of the major environmental cues for an organism to assess daily and seasonal times. Different aspects of fungal developments and behaviors are regulated by quantitatively and qualitatively different spectrums of light. We characterized light regulation in Magnaporthe oryzae, the causal agent of rice blast disease, in which the role light has not been carefully examined. In our current study, we focused on the role of ambient light condition in phenotypes of epidemiological importance. We found that there is a complex light regulation in fungal developments/behavior in M. oryzae; 1) mycelial cells response differently to the same ambient light condition depending on the pre-exposed light condition, 2) Blue light regulates asexual development and asexual spore-release activity, whereas the red light plays a role only in spore release, and 3) M. oryzae senses very dim light (10 µmoles m^-2). We performed microarray experiment using the Agilent chips to study the whole genome expression profile in different light conditions. We also characterized the role of blue light using knockout strains of a blue-light photoreceptor mgwc-1, a homologue of wc-1 in Neurospora crassa. The role of light regulation in plant-microbe interaction especially from the perspective of pathogen will be discussed.