Adaptative and Developmental Responses to Stress in Aspergillus nidulans

Oier      Etxebeste; Unai      Ugalde; Eduardo      A. Espeso

Abstract

Development in the ascomycete A. nidulans is principally determined by environmental signals. Adaptability to oxidative stimuli can derive in changes of growth patterns and/or the activation of sexual or asexual reproductive cycles but this model fungus might also respond to high osmotic or salt concentrations, the redox state, the availability and quantity of carbon or nitrogen sources and the degree or quality of illumination. Since each cell within the colony follows a single morphogenetic program at a time, all these environmental cues might be sensed and integrated into a limited number of intracellular signals which, finally, would activate the required morphogenetic program and repress the others. This signaling mainly occurs through stress response pathways. The present review aims to summarize the available knowledge on how these pathways transduce environmental stimuli to mediate morphological changes in Aspergillus nidulans.

Keywords: Calcium signaling, development, halo-osmotolerance, light response, morphogenesis, nutrient starvation, polarized growth, oxidative stress, salt concentration, morphological transformations, homologoues, plasma membrane receptor, polarity, microtubules, geotropism, autolysis, apoptosis, autopathy, endogenous, exogenous