Simultaneous Changes of Trp 258 to Cys and His 259 to Tyr in Ribosomal Protein L3 in order to Increase Tolerance to DON in Transgenic Tobacco

Another mechanism for reduction the effects of deoxynivalenon toxin (DON) is target site (RPL3 protein) manipulation. In this study amino acid residue 258 is changed from tryptophan to cyctein and 259 from histidine to tyrosine 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 non-transformed tobacco plants in DON assays. Among the mutant types, marked difference with respect to resistance against DON was observed with regenerants expressing LeRPL3WC/HY; 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.