Enzymatic and non-enzymatic antioxidant responses of Carrizo citrange, a salt-sensitive citrus rootstock, to different levels of salinity.
In several plant species, oxidative stress has been shown to be one of the causes of damage produced by salinity. In order to assess the implication of oxidative stress in the reported sensitivity of the citrus rootstock Carrizo citrange to salt stress, 5-month-old seedlings were grown with increasing NaCl concentrations added to the watering solution. As an indicator of oxidative damage, malondialdehyde content was measured. The antioxidant capability of the plants was determined by measuring superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase activities together with the non-enzymatic antioxidant activity. As additional physiological responses to the stress, 1-aminocyclopropane-1-carboxilic acid and proline accumulation were assessed. Data indicate that Carrizo citrange responded to salt-induced oxidative stress by increasing enzymatic and non-enzymatic antioxidant defenses proportionally to the extent of the stress imposed, and that in all plants the malondialdehyde content remained at a moderate level. We suggest that the important deleterious effects reported in Carrizo citrange grown under high NaCl concentrations are mainly due to a cellular intoxication by Cl(-) ions and not to the salt-induced oxidative stress.
Departament de Ciències Experimentals, Universitat Jaume I. Campus de Riu Sec, E-12071 Castelló de la Plana, Spain.
Vicent
V
Arbona
Victor
V
Flors
Josep
J
Jacas
Pilar
P
García-Agustín
Aurelio
A
Gómez-Cadenas
D000222:Adaptation, Physiological / Q000187:drug effects; D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases; D002374:Catalase / Q000378:metabolism; D002957:Citrus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D010544:Peroxidases / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D004798:Enzymes; D012965:Sodium Chloride; D008315:Malondialdehyde; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase