GENES FROM MYCOPARASITIC FUNGI AS A SOURCE FOR IMPROVING PLANT-RESISTANCE TO FUNGAL PATHOGENS

Disease resistance in transgenic plants has been improved, for the fir st time, by the insertion of a gene from a biocontrol fungus, The gene encoding a strongly antifungal endochitinase from the mycoparasitic f ungus Trichoderma harzianum was transferred to tobacco and potato. Hig h expression levels of the fungal gene were obtained in different plan t tissues, which had no visible effect on plant growth and development , Substantial differences in endochitinase activity were detected amon g transformants, Selected transgenic lines were highly tolerant or com pletely resistant to the foliar pathogens Alternaria alternata, A. sol ani, Botrytis cinerea, and the soilborne pathogen Rhizoctonia solani. The high level and the broad spectrum of resistance obtained with a si ngle chitinase gene from Trichoderma overcome the limited efficacy of transgenic expression in plants of chitinase genes from plants and bac teria, These results demonstrate a rich source of genes from biocontro l fungi that can be used to control diseases in plants.