Overexpression of Tamarix albiflonum TaMnSOD increases drought tolerance in transgenic cotton
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Drought is a major environmental stress that limits cotton (Gossypium hirsutum L.) production worldwide. TaMnSOD plays a crucial role as a peroxidation scavenger. In this study, TaMnSOD cDNA of Tamarix albiflonum was overexpressed in the cotton cultivar fy11 by Agrobacterium tumefaciens-mediated transformation. The transformed plants were assessed by gDNA PCR, RT-PCR and DNA gel blot analysis. The physiological and biochemical characters of two independent transgenic lines and control plants were tested and compared, and the morphological traits (biomass, root and lateral root length, leaf number) were also detected after recovery from water-withholding stress. When water was withheld from pot-grown 6-week-old seedlings for 18 days (watering to 8 % of field capacity), transgenic cotton plants accumulated more proline and soluble sugar than wild-type plants (WT). The activity of antioxidant enzymes such as superoxide dismutase and peroxidase was enhanced in transgenic plants under drought stress. Cell membrane integrity was also considerably improved under water stress, as indicated by reduced malondialdehyde content relative to control plants. Furthermore, net photosynthesis, stomatal conductance and transpiration rate were increased in transgenic plants compared with wild type. Transgenic cotton showed increases in biomass as well as root and leaf systems compared with WT after 2 weeks recovery from stress. These results suggest that TaMnSOD transgenic cotton plants acquired improved drought tolerance through enhanced development of the root and leaf system and the regulation of superoxide scavenging.
KeywordsOverexpression TaMnSOD Transgenic cotton Drought tolerance Physiology
This work was supported by grants from The National Basic Research Program, China (2014CB954203) and XinJiang Joint Funds of the National Natural Science Foundation of China (No. U1170304). The authors extend appreciation to Professor Xu Jianhui, Doctor Zhang Da wei from the Economic Crop Research Institute, Xinjiang Academy of Agricultural Sciences, China for their field work support.
- Elżbieta K (2002) Transgenic plants: an insight into oxidative stress tolerance mechanisms. Acta physiol plant 24(1):97–113Google Scholar
- Kochba J, Lavee S, Spiegel PR (1977) Differences in peroxidase activity and isoenzymes in embryogenic and nonembryogenic “Shamouti” orange ovular callus lines. Plant Cell Physiol 18(2):463–467Google Scholar
- Pasapula V, Shen G, Kuppu S, Paez-Valencia J, Mendoza M, Hou P, Chen J, Qiu X, Zhu L, Zhang X, Auld D, Blumwald E, Zhang H, Gaxiola R, Payton P (2011) Expression of an Arabidopsis vacuolar H+-pyrophosphatase gene (AVP1) in cotton improves drought- and salt tolerance and increases fibre yield in the field conditions. Plant Biotechnol J 9(1):88–99PubMedCrossRefGoogle Scholar
- Wang YC, Qu GZ, Li HY, et al (2010) Enhanced salt tolerance of transgenic poplar plants expressing a manganese superoxide dismutase from Tamarix androssowii. Mol Bio Reports 37(2):1119–1124 Google Scholar