Factors affecting delivery of DREB1A gene in maize B73 split-seeds via biolistic system

Immature embryos as a choice tissue for genetic transformation of maize have a few limitations, such as genotype dependence, time-consuming and requiring a well-equipped greenhouse for access, at any time. In the present study, the split-seed explants were used for genetic transformation of maize, B73 line. The transformation of maize split-seed explants from the inbred line B73, for resistance to abiotic stresses was carried out via particle bombardment using pCA-35S-DREB construct, carrying Arabidopsis transcription factor DREB1A under the control of the CaMV 35S promoter and the selectable marker bar. For the optimization of gene-gun transformation parameters, we used two distances, 6 and 9 cm, one or double shooting and pre-treatment culturing of explants. The results showed that double shooting in 9 cm under pre -treatment conditions can improve transient expression of GUS gene in split-seed explants. PCR analysis confirmed the presence of DREB1A and bar genes in one out of 11 transformants. The results showed that split-seeds of B73 line can be used as a suitable explant for maize transformation.