Resistance Of MhMAPK-transgenic Tobacco To Several Abiotic Stresses

The abiotic stresses, such as high salt, heavy metals, drought and so on, are important factors affecting plant growth. Plants can adapt to a variety of abiotic stresses through transmitting stress signal. Mitogen Activated Protein Kinase (MAPK) cascades mediated by Mitogen activated protein kinases (MAPK) is one of the key parts of plant stress signal transduction., isolated from apple rootstocks called Malus hupehensis (Pamp) Rehd. var pinyiensis Jiang,is homologous gene of MAPK. In this study, we made tobacco transfered MhMAPK as material, through high salt, high temperature, drought, copper sulfate and oxidative stress treatment, in order to initially reveal the role of MhMAPK in aptation to stresses of apple rootstocks, we made analysis and comparison of changes of seed germination, root growth, MhMAPK expressioncell, apoptosis and antioxidant capacity between transgenic and wild-type tobacco. The main results are as follows:(1) We got three strains of MhMAPK-transgenic tobacco through screening of knamycin medium:TG-11, TG-16and TG-18. The MhMAPK expression level of three transgenic lines were all significantly higher than the wild-type strain of tobacco.(2) The oxidative stress, induced by high temperature, drought, NaCl, CUSO4and methyl viologen (MV) treatments, made the MhMAPK expression level of all the tobaccos significantly higher than the control group, but the increased range of three transgenic lines were significantly higher than the wild-type tobacco.(3) The germination and root length of MhMAPK-transgenic tobaccos were slightly higher than the wild-type tobacco; high temperature, drought, NaCl, CUSO4and methyl viologen (MV) stress treatments made the germination and root length of all the tobaccos decreased, but the decreased range of three transgenic lines were significantly lower than the wild-type tobacco, and the growing state of three transgenic lines were better than the wild-type tobacco.(4) In the high temperature, drought, NaCl, CUSO4and methyl viologen (MV) stress treatments, the increased rate of active oxygen of transgenic tobaccos were significantly lower than the wild-type tobacco, and the activity and increased range of antioxidant enzymes were significantly higher than the wild-type tobacco. (5) In the high temperature, drought, NaCl, CUSO4and methyl viologen (MV) stress treatments, the increased range of free proline and soluble sugar content of transgenic tobaccos were significantly higher than the wild-type tobacco, and increased range of apoptosis rate and content of MDA of transgenic tobaccos were significantly lower than the wild-type tobacco.(6) Chlorophyll content of MhMAPK-transgenic tobaccos were significantly higher than the wild-type tobacco, high temperature, drought, NaCl, CUSO4and methyl viologen (MV) stress treatments made the Chlorophyll content of all the tobaccos decreased, but the decreased range of three transgenic lines were significantly lower than the wild-type tobacco.