Biotic activation of abiotic temperature stress tolerance in transgenic BT and wild type cotton

Abstract

Activation of abiotic temperature stress tolerance in transgenic Bt and non-Bt cotton was studied using Pseudomonas fluorescens as biotic regulator. Seeds germinated at different temperatures after the bacterial treatment exhibited variation at the temperatures of 30°C and 37°C as measured in terms of percent seed germination in both Bt and non-Bt cotton. Pseudomonas treatment enhanced the seed germination in non-Bt cotton at 30°C. Enhancement of seed germination in Bt cotton was significant at 37°C after bacterial treatment. At elevated temperature of 45°C, neither Bt nor non-Bt seeds germinated, irrespective of Pseudomonas treatment. The temperature of 30°C supported better shoot and root growth of seedlings as compared to other temperatures tested. Pseudomonas treatment resulted in enhanced shoot and root length of Bt cotton seedlings at 30°C, whereas at 37° Chad negligible influence. Non-Bt cotton seeds treated with bacteria failed to show significant variation in root and shoot growth compared to untreated control. Activity gelelectrophoresis carried out to study the expression of superoxide dismutase revealed that the SOD activity in both Bt and non-Bt cotton was enhanced due to Pseudomonas seed treatment.