Effects of cryptogein gene on growth, phenotype and secondary metabolite accumulation in co-transformed roots and plants of Tylophora indica

摘要

Tylophora indica, an indigenous medicinal plant, was transformed with the cryptogein gene to determine the effect of crypt gene on secondary metabolites in co-transformed roots and plants via Agrobacterium rhizogenes mediated transformation. The Ri crypt co-transformed roots and plants showed expression of crypt gene. Southern hybridization specifies that crypt gene has been transferred and positively integrated into the Ri crypt co-transformed plant. AFLP fingerprinting revealed high degree of genetic similarity among the Ri-transformed and Ri crypt co-transformed cultures. The expression of crypt gene stimulated phenolic compound accumulation in transformed root and plants while tylophorine content was comparable in Ri transformed and Ri crypt co-transformed root lines and plants. The Ri crypt co-transformed root lines showed significantly higher (p = 0.05) phenolics production (caffeic acid, 1.8-2.9-fold; p-coumaric acid, 1.9-fold and ferulic acid, 1.5-2-fold) compared to Ritransformed root lines. The roots of Ri crypt co-transformed plants showed a significantly (p = 0.05) higher content of caffeic acid (1.19-fold) and ferulic acid (1.53-fold) than Ri-transformed plants. It is suggested that crypttransformed plants can also be used as a tool to elucidate the biochemical basis of defense responses as phenolics are known to play a role in providing defense barriers to infection by pathogen.