| dc.description.abstract | An efficient procedure of genetic transformation ultimately can accelerate the process of cultivar development of maize. The objective of this study was to evaluate the effect of L-cysteine added to co-cultivation medium on the efficiency of Agrobacterium-mediated transformation of two genotypes of maize. Explants of immature embryos were isolated from immature ears genotypes Hi-II and Tom Thumb harvested 11-13 days after pollination. Then explants were inoculated with Agrobacterium strain C58C1 carrying pPTN345 vector and cultured in co-cultivation medium for 2 days then on delay medium for 14 days, on selection medium for 4 x 14 days, on regeneration medium, and finally on germination medium. Co-cultivation media contained either 0 or 100 mg/L L-cysteine. Based on assay at 2 days after inoculation,the transient expression of GUS at scutelar side of explants co-cultivated on medium containing 100 mg/L cysteine was higher than that of the control (0 mg/L cysteine). Transient expression of GUS on the explants of Tom Thumb was higher than that of Hi-II. However, transgenic plants in this study were only produced from Hi-II explants co-cultivated in a medium amended with 100 mg/L L-cysteine. No transgenic plants was produced from explants of Tom Thumb due to low efficiency of induction of embriogenic calli. The efficiency of transformation using explants of Hi-II cocultivated in a medium amended with 100 mg/L L-cysteine was 4 independent transformants or transgenic plants out of 70 explants inoculated or 5.7%. | id |
