Transgenic tobacco plants overexpressing chitinases of fungal origin show enhanced resistance to biotic and abiotic stress agents.

Genes encoding defense-related proteins have been used to alter the resistance of plants to pathogens and other environmental challenges, but no single fungal gene overexpression has produced broad-spectrum stress resistance in transgenic lines. We have generated transgenic tobacco (Nicotiana tabacum) lines that overexpress the endochitinases CHIT33 and CHIT42 from the mycoparasitic fungus Trichoderma harzianum and have evaluated their tolerance to biotic and abiotic stress. Both CHIT33 and CHIT42, individually, conferred broad resistance to fungal and bacterial pathogens, salinity, and heavy metals.

Post-transcriptional control of a glucoamylase gene from Trichoderma harzianum under stress conditions.

We have examined the regulation of Trichoderma harzianum glucoamylase gene (Gla66) in response to different growth conditions. Transcription of the Gla66 gene is initiated from two different sites, yielding two transcripts of 2.1 kb and 2.