Agrobacterium mediated transformation of Brassica juncea with Arabidopsis annexin (AnnAtl) gene

摘要

Annexin (AnnAtl) gene from Arabidopsis thaliana was introduced into Brassica juncea by Agrobacterium tumefaciens mediated transformation. Hypocotyls from 5-day-old seedlings of Brassica juncea cv RLM 198 with 2 day preculture were infected with Agrobacterium strain GV2260 and GV3101 harboring a binary vector containing Annexin (AnnAt1) gene. It was observed that the Agrobacterium strain GV3101 transformed the Brassica hypocotyls with more efficiency than the strain GV2260. A total of 1716 hypocotylsof Brassica juncea cv RLM 198 co-cultured with GV3101 strain, showed average callusing of 57% and shoot regeneration of 13 % in MS medium supplemented with 5.37 muM NAA, 4.44 muM BAP, 20 muM AgNO_3 and 86muM kanamycin as selective agent. A total of 108 kanamycin resistant plantlets were regenerated. PCR was used to identify and characterize the transformed plantlets. Finally, five T_0 plants were hardened in transgenic glass house and scored for incidence of Alternaria blight. At least one T_0 plant showed a decrease in area and number of necrotic lesions when compared with untransformed control plant. This has suggested that presence of Arabidopsis annexin (AnnAt 1) which is anti-oxidative in nature, modulated defense response in Brassica plants. Theheritability analysis of T_1 progeny of a T_0 plant for annexin gene by PCR has further suggested that the T_0 plant had mosaics of transformed and untransformed sectors at organ level.