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Lipoic acid and redox status in barley plants subjected to salinity and elevated CO 2
Author(s) -
PérezLópez Usue,
Robredo Anabel,
Lacuesta Maite,
Sgherri Cristina,
MenaPetite Amaia,
NavariIzzo Flavia,
MuñozRueda Alberto
Publication year - 2010
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2010.01361.x
Subject(s) - glutathione , hordeum vulgare , oxidative stress , antioxidant , salinity , chemistry , reactive oxygen species , alpha lipoic acid , metabolite , cultivar , lipoic acid , biochemistry , food science , horticulture , enzyme , botany , biology , poaceae , ecology
Future environmental conditions will include elevated concentrations of salt in the soil and an elevated concentration of CO 2 in the atmosphere. Because these environmental changes will likely affect reactive oxygen species (ROS) formation and cellular antioxidant metabolism in opposite ways, we analyzed changes in cellular H 2 O 2 and non‐enzymatic antioxidant metabolite [lipoic acid (LA), ascorbate (ASA), glutathione (GSH)] content induced by salt stress (0, 80, 160 or 240 m M NaCl) under ambient (350 µmol mol −1 ) or elevated (700 µmol mol −1 ) CO 2 concentrations in two barley cultivars ( Hordeum vulgare L.) that differ in sensitivity to salinity (cv. Alpha is more sensitive than cv. Iranis). Under non‐salinized conditions, elevated CO 2 increased LA content, while ASA and GSH content decreased. Under salinized conditions and ambient CO 2 , ASA increased, while GSH and LA decreased. At 240 m M NaCl, H 2 O 2 increased in Alpha and decreased in Iranis. When salt stress was imposed at elevated CO 2 , less oxidative stress and lower increases in ASA were detected, while LA was constitutively higher. The decrease in oxidative stress could have been because of less ROS formation or to a higher constitutive LA level, which might have improved regulation of ASA and GSH reductions. Iranis had a greater capacity to synthesize ASA de novo and had higher constitutive LA content than did Alpha. Therefore, we conclude that elevated CO 2 protects barley cultivars against oxidative damage. However, the magnitude of the positive effect is cultivar specific.