Overexpression of bacterial gene improves the resistance of modified tomato plant against f. sp. .

Tomato ( L.) yield is severely affected by fungal disease. To improve the resistance of tomato against Fusarium oxysporum f. sp. lycopersici (FOL), Escherichia coli katE gene was transformed into two tomato cultivars, namely Castle Rock and Super strain B, via ; the transformation efficiency was 5.6% and 3.5%, respectively. The integration of the gene into T, T, and T transgenic tomato lines was confirmed using PCR. In addition, DNA dot blot technique confirmed the integration of the gene into T transgenic tomato lines. The RT-PCR analysis confirmed that the gene could be expressed normally in the T modified lines. Under artificial infection with FOL, the non-modified plants exhibited more severe fungal disease symptoms than those observed in overexpression (OE) lines. Our analysis showed that the levels of three defense enzymes, namely superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), were increased during transgenic T generation pre-treated with FOL. The bioassay of modified lines revealed that an average of 52.56% of the modified Castle Rock cultivar and 50.28% of the modified Super Strain B cultivar showed resistance under infection. These results clearly indicate that the modified tomato plants, in which the gene was overexpressed, became more resistant to the infection by FOL than the wild-type plants. Our study has proven that the overexpression of the gene in the OE lines could be utilized to develop and improve the resistance against fungal diseases in the modified crops.