Physiological and Biochemical Changes of IrlVHA-c gene Transgenic Tobacco Seedlings and Self-crossed Progeny Under NaHCO3 Stress

In order to study the alkali resistivity of VHA-c in Iris lacteal. (IrlVHA-c), the transgenic tobacco seedlings harboring IrlVHA-c gene from Iris lactea (T₀), the self-crossed progeny (T₁), and the non-transgenic lines of tobacco seedlings were grown in Hoagland nutrient solutions supplemented with 0, 100, 200, 300, 400 mmol ? L^?1 NaHCO₃. The MDA content, CAT, POD and SOD activity, electrical conductivity, chlorophyll content, soluble sugar content, proline content and polyphenol oxidase activity of the seedlings were determined. The results showed that the transgenic lines of tobacco maintained a high activity up to 200 mmol ? L^?1 NaHCO₃, and activity was slightly lower at 300 mmol ? L^?1 NaHCO₃. When the concentration of NaHCO₃ was as high as 400 mmol ? L^?1 the seedlings were badly hurt. In addition, the activity of T₀ and T₁ transgentic tobacoo was maintained more or less. While the non-transgenic lines of tobacco could maintain viably up to 100 mmol ? L^?1 NaHCO₃, and they could not survive at 400 mmol ? L^?1 NaHCO₃. The conclusion was drawn that the alkali resistance of the tobacoo transformed IrlVHA-c was noticeably improved.