Highly efficient Agrobacterium-mediated in planta genetic transformation of snake gourd (Tricosanthes cucumerina L.)

摘要

Regeneration of plants from Agrobacterium tumefaciens infected cell or tissue is a time-consuming process and somaclonal variations are the major bottleneck. Hence, in the present study, a tissue culture-independent genetic transformation system for snake gourd was developed using seed as an explant. Snake gourd seeds were infected with three A. tumefaciens strains harbouring pGA 492 plasmid, and the transformants were selected against BASTA(A (R)). Several factors influencing the in planta genetic transformation such as Agrobacterium strains, acetosyringone, sonication, and vacuum infiltration, have been evaluated. The maximum transformation efficiency (19.6 %) was recorded when the pre-cultured snake gourd seeds were sonicated for 30-min and vacuum infiltrated for 3-min at 750 mm of Hg in A. tumefaciens EHA 105 suspension containing 100 A mu M of acetosyringone. The bar gene integration into the snake gourd genome was confirmed by polymerase chain reaction and Southern blot hybridization. The transgene was successfully inherited into the T-1 progeny plants. This transformation method can produce transgenic snake gourd plants in a relatively short time (35-days).