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https://doi.org/10.2478/botcro-2013-0010

Salt stress tolerance in cowpea is poorly related to the ability to cope with oxidative stress

Sidney C. Praxedes ; Unidade Acadêmica Especializada em Ciências Agrárias, Universidade Federal do Rio Grande do Norte, RN 160, km 03, Distrito de Jundiaí, 59280-000 Macaíba-RN, Brazil
Fabio M. Damatta ; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36571-000 Viçosa, Minas Gerais, Brazil
Claudivan F. Lacerda ; Departamento de Engenharia Agrícola, Universidade Federal do Ceará, 60455-760 Fortaleza, Ceará, Brazil
Jose T. Prisco ; Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal/CNPq), Universidade Federal do Ceará, Caixa Postal 6039, 60440-970 Fortaleza, Ceará, Brazil
Eneas Gomes-Filho ; Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal/CNPq), Universidade Federal do Ceará, Caixa Postal 6039, 60440-970 Fortaleza, Ceará, Brazil

Sažetak

We have previously demonstrated that salt tolerance in cowpea could be associated with lesser impairments of the photosynthetic capacity. Taking into account that photosynthesis is the main sink for reducing power consumption, our central working hypothesis is that a salt- sensitive cultivar is more prone to suffer from oxidative stress. We analyzed the long-term effects of salt stress on oxidative damage and protection against reactive oxygen species in both leaves and roots of a salt-tolerant (Pitiúba) and a salt-sensitive (TVu) cowpea cultivar. Two salt treatments (0 and 75 mM NaCl) were applied to 10-day-old plants grown in nutrient solution for 24 days. Significant salt-induced oxidative damage as demonstrated via increases in malondialdehyde concentration were noted, particularly in leaves at the end of the experiment, although such damage was found earlier in Pitiúba. In salt-stressed plants, superoxide dismutase (SOD) activity increased only in Pitiúba at 24 days from the start of salt additions (DSSA). In Pitiúba, catalase (CAT) was not significantly affected by the treatments, whereas in TVu its activity was dramatically lower in salt- tressed plants at 10DSSAonwards. In general salt stress led to significant increases, much more pronounced in ascorbate peroxidase (APX), glutathione reductase (GR) and guaiacol peroxidase (GPX), at the end of the experiment in both cultivars. In roots, salt-induced increases in enzyme activities were particularly noted at 24 DSSA, as found for SOD and APX in Pitiúba, CAT in TVu and GR and GPX in both cultivars. Therefore, in contrast to our expectations, the present results argue, to a great extent, against a functional link between salt stress tolerance and the expression of the antioxidant system. We also demonstrated that leaves and roots should be evaluated for a full assessment of whole plant acclimation to salt stress.

Ključne riječi

Antioxidative defense; oxidative stress; salt tolerance; Vigna unguiculata

Hrčak ID:

118989

URI

https://hrcak.srce.hr/118989

Datum izdavanja:

1.4.2014.

Posjeta: 2.173 *