Expression of a rice chitinase gene enhances antifungal potential in transgenic grapevine (<i>Vitis vinifera</i> L.)

Abstract

To enhance the antifungal potential of grapevine, transgenic plants were generated by transferring rice chitinase gene under a maize-ubiquitin promoter along with its first intron into the leaf disc-induced somatic embryos via Agrobacterium mediated transformation. After co-cultivation for 2 days with recombinant Agrobacterium, somatic embryos were transferred onto WPM medium containing BAP 1.5 μM and NAA 0.1 μM supplemented with 25 mg/L hygromycin. Secondary or tertiary embryos were selected and the antibiotic resistant transgenic plantlets were analyzed. The integration and stability of the transgene were confirmed by PCR, RT-PCR, Southern blotting and by Western blot analyses. The transgenic plants exhibited higher chitinase activity than the non-transformed plants. These analyses indicated that the foreign gene was translated into the protein of expected molecular weight that showed chitinase activity. Following in vitro inoculation of powdery mildew (Uncinula necator), the transgenic plants showed delayed onset of the disease and smaller lesions. The transgenic plants were adapted to the greenhouse and did not show any phenotypic alterations.