Genetic Manipulation of Tomato (Solanum lycopersicum) cv. PKM-1 using cry2AX1 Gene for Insect Resistance

Cotyledonary explants of tomato cv. PKM-1 were co-cultivated with Agrobacterium tumefaciens strain, LBA4404 harbouring a codon-optimised chimeric cry2AX1 gene driven by enhanced CaMV35S promoter in pCAMBIA2300 vector backbone. Ninety six putative transgenic plants were regenerated, and the presence of the cry2AX1 gene in fifty eight plants was demonstrated by PCR analysis. ELISA showed that nine out of the fifty eight plants had detectable level of Cry2AX1 protein expression, which ranged from 0.030 to 0.388 µg/g of fresh tissue. Insect bioassay of transgenic T0 tomato plants using H. armigera neonates recorded a mortality of 16.67 to 100 per cent and showed significant reduction in leaf feeding and inhibition of growth in surviving larvae. The results demonstrated the potential of the chimeric cry2AX1 gene in developing H. armigera resistant transgenic tomato varieties.