Agrobacterium-mediated GUS Expression in Bitter Gourd (Momordica charantia L.)

Multiple shoots from the immature cotyledonary nodes of two genotypes of bitter gourd were induced in MS media with GA3, IAA, IBA, NAA, KIN and BAP. The shoots continued to increase in number for 5-6 weeks. On the medium, BAP 2 mg L-1 in combination with 0.1 mg L-1 IAA + 2 mg L-1 GA3 was the most effective medium for adventitious shoot proliferation from immature cotyledonary node. BGGB1 and BGGB14 genotypes produced over 84 and 80% shoots, respectively on this medium in 6 weeks from the time at inoculation of primary explants. BGGB1 was found to be better in response than BGGB14 in most of the treatments. Rapid and reproducible transformation system for bitter gourd using Agrobacterium tumefaciens mediated gene delivery was developed. Immature cotyledonary node from green immature fruits that has been allowed to imbibe was used as explant and regeneration was achieved. Cotyledonary node was co-cultured in MS media with 2.0 mg L-1 BAP + 0.1 mg L-1 IAA + 2.0 mg L-1 GA3. Histochemical GUS assay of the explants and shoots (newly formed) revealed that they were GUS positive.