The photolyase gene from the plant pathogen Fusarium oxysporum f. sp lycopersici is induced by visible light and α-tomatine from tomato plant

Survival of irradiated spores from Fusarium oxysporum with ultraviolet radiation (UV) was increased following exposition to visible light, indicating that this phytopathogenic fungus has a mechanism of photoreactivation able to counteract the lethal effects of UV. A genomic sequence containing the complete photolyase gene (phr1) from F oxysporum was isolated by heterologous hybridisation with the Neurospora crassa photolyase gene. The F oxysporum phr1 cDNA was isolated and expressed in a photolyase deficient Escherichia coli strain. The complementation of the photoreactivation deficiency of this E coli mutant by phr1 cDNA demonstrated that the photolyase gene from F oxysporum encodes a functional protein. The F oxysporum PHR1 protein has a domain characteristic of photolyases from fungi (Trichoderma harziaium, N. crassa, Magnaporthe grisea, Saccharomyces cerevisiae) to bacteria (E coli), and clusters in the photolyases phylogenetic tree with fungal photolyases. The F oxysporum phr1 gene was inducible by visible light. The phr1 expression was also detected in presence of alpha-tomatine, a glycoalkaloid from tomato damaging cell membranes, suggesting that phr1 is induced by this cellular stress. (C) 2003 Elsevier Inc. All rights reserved.