caa a22 4500 445841125 CHVBK 20180317145344.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10725-010-9547-9 doi (NATIONALLICENCE)springer-10.1007/s10725-010-9547-9 Effects of citric acid as an important component of the responses to saline and alkaline stress in the halophyte Leymus chinensis (Trin.) [Elektronische Daten] [Yan-Lin Sun, Soon-Kwan Hong] Some plants accumulate some compatible solutes and exude various organic acids when exposed to environmental stress. These compatible solutes including proline have been suggested to be involved in stress tolerance by maintaining sufficient cell turgor for growth, thereby improving plant growth, protecting enzymes, and membranes. However, less evidence exists regarding the protective roles of organic acids under stress conditions. Here, we investigate the effects of citric acid as a component of the response to stress on plant growth and antioxidant enzyme activities in two genotypes of halophyte Leymus chinensis (Trin.) genotypes, LcWT07 and LcJS0107. Data showed that both saline stress (200mM NaCl) and alkaline stress (100mM Na2CO3) reduced plant growth on the relative growth rate and CO2 assimilation rate, but increased the citric acid concentrations in 6-week-old plants over the 72h experimental period. When 50mgl−1 citric acid was exogenously applied under stress conditions, it significantly improved the plant growth and internal citric acid concentration, and also induced defense mechanisms by increasing the activities of antioxidant enzymes. To compare with the mitigative effects of exogenous citric acid on stress, exogenous application of proline was also performed under same conditions, and similar effects on the improvement of growth were observed. Based on these results, we suggested that citric acid is an important component of the stress response in L. chinensis, and exogenous application of 50mgl−1 citric acid might play a positive role on stress tolerance. Springer Science+Business Media B.V., 2010 Alkaline stress nationallicence Citric acid accumulation nationallicence Exogenous proline nationallicence Leymus chinensis nationallicence Saline stress nationallicence PPFD : Photosynthetic photon flux density nationallicence MCW : Methanol/Chloroform/Water nationallicence MDA : Malonyldialdehyde nationallicence TCA : Trichloroacetic acid nationallicence TBA : Thiobarbituric acid nationallicence PVP : Polyvinylpyrrolidone nationallicence SOD : Superoxide dismutase nationallicence NBT : Nitroblue tetrazolium nationallicence CAT : Catalase nationallicence APX : Ascorbate peroxidase nationallicence ANOVA : Analysis of variance nationallicence Sun Yan-Lin Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, 200-701, Chuncheon, Kangwon-Do, Korea aut Hong Soon-Kwan Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, 200-701, Chuncheon, Kangwon-Do, Korea aut Plant Growth Regulation Springer Netherlands 64/2(2011-06-01), 129-139 0167-6903 64:2<129 2011 64 10725 https://doi.org/10.1007/s10725-010-9547-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10725-010-9547-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sun Yan-Lin Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, 200-701, Chuncheon, Kangwon-Do, Korea aut NATIONALLICENCE 700 1- Hong Soon-Kwan Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, 200-701, Chuncheon, Kangwon-Do, Korea aut NATIONALLICENCE 773 0- Plant Growth Regulation Springer Netherlands 64/2(2011-06-01), 129-139 0167-6903 64:2<129 2011 64 10725 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer