Анотация: In order to reduce the effects of DON, amino-acid residue 258 is changed from tryptophan to arginine and 259 from histidine to cyctein in tomato ribosomal protein L3 (LeRPL3) cDNA through Site Directed Mutagenesis (SDM). Transgenic tobacco plants expressing these modified LeRPL3 cDNAs were tested for ability of leaf discs to regenerate and produce callus in the presence of DON. Significant differences in callus induction and ability to undergo regeneration was seen in transformed lines as compared to nontransformed tobacco plants in DON assays. Among the mutant types, marked difference with respect to resistance against DON was observed and plants expressing LeRPL3H259Y giving better response than transforments expressing LeRPL3W258C. The results indicate the possibility of increase in DON tolerance (and Fusarium head blight resistance respectively) among the plants based on expression of engineered RPL3