Preliminary Study Onβ-Aminobutyric Acid Induce Tobacco Against Copper,Cadmium Stress

With the rapid development of urbanization and industrialization, a lot of harmful heavy metals such as copper and cadmium are released to the air, soil, water, stay in the ecosystem, accumulate and migrate, eventually cause great harm to human health and plant growth.As a non-protein amino acid, β-aminobutyric acid (BABA) could induce various stress tolerances in plants. Based on the investigation of tabacoo, we studied several issues including the bud seedling growth and metabolism of reactive oxygen species at different concentrations of BABA. The expression of gene transported by copper and the role of glutathione (GSH) in resisting the cadmium stress are also studied. The results showed that:1. The tobacco seedlings treated with BABA could promote the root growth and increase the fresh weight of tobacco compared with non-treatment considering that the root growth is usually restrained under100μmol/L copper stress or75μmol/L cadmium stress.2. BABA treatment could decrease the H2O2and MDA content in tobacco seedlings under copper or cadmium stress according to the results of physiological indexes.3. BABA could improve the activities of antioxidative enzymes (SOD, POD, and APX) of tobacco under the copper or cadmium stress, at the same time, reduce the oxidative damage to tobacco caused by heavy metals.4. Expression levels of NtNRAMP, NtYSL and NtPDR family genes could significantly increase, which regulate the transportation of divalent metal.5. By adding50μmol/L BSO to the medium containing75μmol/L of cadmium chloride, we found that the GSH content in tobacco is crucial to tobacco cadmium tolerance. The decreased GSH content could bring the decrease of tolerance to cadmium in tobacco. BABA could induce elevated content of GSH in vivo, and strengthen the tolerance to cadmium in tobacco.Conclusion:1. through adjusting the content of active oxygen, enzyme activities of antioxidant and controlling the expression of genes related to the transportation of metal ions, BABA could increase the resistance of tobacco to copper stress.2. Through adjusting the content of active oxygen, enzyme activities of antioxidant and improving the content of GSH, BABA could increase the resistance of tobacco to cadmium stress.