Effect of exogenous selenium supply on photosynthesis, Na+accumulation and antioxidative capacity of maize (Zea mays L.) under salinity stress.
The mechanism of selenium-mediated salt tolerance has not been fully clarified. This study investigated the possible role of selenium (Se) in regulating maize salt tolerance. A pot experiment was conducted to investigate the role of Se (0, 1, 5 and 25 μM Na2SeO3) in photosynthesis, antioxidative capacity and ion homeostasis in maize under salinity. The results showed that Se (1 μM) relieved the salt-induced inhibitory effects on the plant growth and development of 15-day-old maize plants. Se application (1 μM) also increased the net photosynthetic rate and alleviated the damage to chloroplast ultrastructure induced by NaCl. The superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities were increased, and ZmMPK5, ZmMPK7 and ZmCPK11 were markedly up-regulated in the roots of Se-treated plants, likely contributing to the improvement of antioxidant defence systems under salinity. Moreover, 1 μM Se increased K+in the shoots while decreasing Na+in the roots, indicating that Se up-regulates ZmNHX1 in the roots, which may be involved in Na+compartmentalisation under salinity. The findings from this single experiment require repetition together with measurement of reactive oxygen species (ROS), but nevertheless suggest that exogenous Se alleviates salt stress in maize via the improvement of photosynthetic capacity, the activities of antioxidant enzymes and the regulation of Na+homeostasis.
Tobacco Research Institute/Maize Research Center, Anhui Academy of Agricultural Sciences, Hefei 230031, P. R. China.|State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P. R. China.
Chaoqiang
C
Jiang
Tobacco Research Institute/Maize Research Center, Anhui Academy of Agricultural Sciences, Hefei 230031, P. R. China.
Chaolong
C
Zu
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P. R. China.
Dianjun
D
Lu
College of Natural Resources and Environmental Science, Key Laboratory of Marine Biology, Nanjing Agricultural University, Nanjing 210095, P. R. China.
Qingsong
Q
Zheng
Tobacco Research Institute/Maize Research Center, Anhui Academy of Agricultural Sciences, Hefei 230031, P. R. China.
Jia
J
Shen
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P. R. China.
Huoyan
H
Wang
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P. R. China.
Decheng
D
Li
D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism; D002736:Chloroplasts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017136:Ion Transport / Q000187:drug effects; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects* / Q000235:genetics; D018515:Plant Leaves / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology; D054712:Salinity; D036226:Seedlings / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D012643:Selenium / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D007527:Isoenzymes; D020011:Protective Agents; D017923:Sodium-Hydrogen Exchangers; D012964:Sodium; D060387:Ascorbate Peroxidases; D013482:Superoxide Dismutase; D020928:Mitogen-Activated Protein Kinases; D012643:Selenium; D011188:Potassium