caa a22 4500 606219242 CHVBK 20210128101117.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s11104-015-2434-4 doi (NATIONALLICENCE)springer-10.1007/s11104-015-2434-4 Effects of 1-aminocyclopropane-1-carboxylate (ACC) deaminase-overproducing Sinorhizobium meliloti on plant growth and copper tolerance of Medicago lupulina [Elektronische Daten] [Zhaoyu Kong, Bernard Glick, Jin Duan, Shulan Ding, Jie Tian, Brendan McConkey, Gehong Wei] Background and aims: Rhizobia typically produce a lower level of ACC deaminase compared with free-living plant growth-promoting bacteria. While the endogenous rhizobial ACC deaminase is important in legume nodulation, it is not sufficient to protect host plants against environmental stresses. The main goal of this study was to assess the effects of a genetically engineered Sinorhizobium meliloti strain overproducing ACC deaminase, and its symbiotic performance in Medicago lupulina under copper stress conditions. Methods: The engineered strain was transformed with an exogenous acdS gene by triparental conjugation. A plant growth assay was conducted to assess its plant growth promotion ability under copper stress conditions. The expressions of antioxidant genes in these plants were analyzed using quantitative real-time PCR. Results: Plants nodulated with the engineered strain showed a greater dry weight, a decreased ethylene level in roots, a higher total copper uptake but a lower level of copper translocation to aerial parts, as compared with the plants nodulated with the wild-type strain under copper stress conditions. These results were positively correlated with higher expression of antioxidant genes in the roots of these plants exposed to severe copper stress. Conclusions: The engineered strain could improve plant growth as well as copper tolerance of M. lupulina, and enhance the antioxidant defense system. Springer International Publishing Switzerland, 2015 ACC deaminase nationallicence Symbiosis nationallicence Excess copper nationallicence Antioxidant responses nationallicence Phytoremediation nationallicence Kong Zhaoyu State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China aut Glick Bernard Department of Biology, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, Ontario, Canada aut Duan Jin Department of Biology, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, Ontario, Canada aut Ding Shulan State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China aut Tian Jie College of Horticulture, Nanjing Agricultural University, 210095, Nanjing, China aut McConkey Brendan Department of Biology, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, Ontario, Canada aut Wei Gehong State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China aut Plant and Soil Springer International Publishing 391/1-2(2015-06-01), 383-398 0032-079X 391:1-2<383 2015 391 11104 https://doi.org/10.1007/s11104-015-2434-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-015-2434-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kong Zhaoyu State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China aut NATIONALLICENCE 700 1- Glick Bernard Department of Biology, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, Ontario, Canada aut NATIONALLICENCE 700 1- Duan Jin Department of Biology, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, Ontario, Canada aut NATIONALLICENCE 700 1- Ding Shulan State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China aut NATIONALLICENCE 700 1- Tian Jie College of Horticulture, Nanjing Agricultural University, 210095, Nanjing, China aut NATIONALLICENCE 700 1- McConkey Brendan Department of Biology, University of Waterloo, 200 University Avenue West, N2L 3G1, Waterloo, Ontario, Canada aut NATIONALLICENCE 700 1- Wei Gehong State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, 712100, Yangling, Shaanxi, China aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 391/1-2(2015-06-01), 383-398 0032-079X 391:1-2<383 2015 391 11104