GERMINATING CONIDIOSPORES OF ASPERGILLUS AMINO-ACID AUXOTROPHS ARE HYPERSENSITIVE TO HEAT-SHOCK, OXIDATIVE STRESS AND DNA-DAMAGE

Germinating conidiospores (conidia) of Aspergillus nidulans amino acid -requiring strains are hypersensitive to heat, oxidative stress, UV ra diation and chemical mutagens when compared with other strains. They a lso showed an increased mutation rate. Sensitivity to stress condition s has been correlated with an abnormal RAS/cAMP pathway in mutants of S. cerevisiae. We suggest that the RAS/cAMP pathway is defective in ge rminating conidia of Aspergillus amino acid auxotrophs and that this i s responsible for suppressing DNA repair and conferring sensitivity to oxidative stress and heat shock.