Tolerance of pea (Pisum sativum L.) to long‐term salt stress is associated with induction of antioxidant defences

Abstract

Using two cultivars of Pisum sativum L. with different sensitivity to NaCl, the effect of long-term (15 d) NaCl (70 mM) treatments on the activity and expression of the foliar ascorbate-glutathione cycle enzymes, superoxide dismutase isozymes and their mRNAs was evaluated and related to their ascorbate and glutathione contents. High-speed supernatant (soluble) fractions, enriched for cytosolic components of the antioxidant system, were used. In this fraction from the NaCl-tolerant variety (cv Granada), the activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), Mn-superoxide dismutase (Mn-SOD) and dehydroascorbate reductase (DHAR) increased, while CuZn-SOD activity remained constant. In the NaClsensitive plants (cv Challis), salinity did not produce significant changes in APX, MDHAR and GR activities. Only DHAR activity was induced in cv Challis, whereas soluble CuZn-SOD activity decreased by about 35%. Total ascorbate and glutathione contents decreased in both cultivars, but the decline was greater in NaCl-sensitive plants. This difference between the two cultivars was more pronounced when the transcript levels of some these enzymes were examined. Transcript levels for mitochondrial Mn-SOD, chloroplastic CuZn-SOD and phospholipid hydroperoxide glutathione peroxidase (PHGPX), cytosolic GR and APX were strongly induced in the NaCl-tolerant variety but not in the NaCl-sensitive variety. These data strongly suggest that induction of antioxidant defences is at least one component of the tolerance mechanism of peas to long-term salt-stress.

ASCORBIC ACID FOLIIAR SPRAY COUNTERACTING EFFECT OF SALINITY ON GROWTH, NUTRIENTS CONCENTRATIONS, PHOTOSYNTHESIS, ANTIOXIDANT ACTIVITIES AND LIPID PEROXIDATION OF BEAN (<i>PHASEULUS VULGARIS</i> L.) CULTIVARS

“…Poly-Unsaturated Fatty Acids (PUFA) are the main membrane lipid components susceptible to peroxidation and degradation (Elkahoui et al, 2005). The increase in LP, as caused by NaCl stress in the present study, can be correlated to ion accumulation and AOS production under salt stress (Hernandez et al, 2000). The LP level indicates the extent of salt tolerance in the given cultivars (Bor et al, 2003;Neto et al, 2006).…”

Exogenous salicylic acid alleviates cold damage by regulating antioxidative system in two barley (Hordeum vulgareL.) cultivars

“…This can be an important difference at antioxidative response to cold stress since cold tolerance of the varieties is different. Although the endogenous SA contents were decreased by the cold treatment in the present study, endogenous SA levels were increased by UV light, ozone (Yalpani et al 1994), salt (Hernandez et al 2000) and drought stress Figure 6. The effects of cold treatment on endogenous SA content in the leaves of two barley cultivars differing at cold tolerance.…”

“…These data suggest that the CAT activity can be significantly affected by cold stress. The stimulation of CAT activity by biotic and abiotic stresses is a phenomenon that occurs in many different kinds of plant species (Vanacker et al 1998;Hernandez et al 2000;Patykowski and Urbanek, 2003;Tasgin et al 2006;Mutlu et al 2009a). When the results of H 2 O 2 content and CAT activity obtained from the both cold-treated barley plants are connected, it is seen that the decrease in the H 2 O 2 content was parallel with the increase in the CAT activity (Figure 2 and 3).…”

Biochemical components and dry matter of lemon and mandarin hybrids under salt stress

“…Since carotenoids can act as antioxidant agents, Hernández et al (2000) obtained the lipid membranes of the oxidative stress generated in plants exposed to salinity (Falk & Munné-Bosch, 2010). In addition, the contents of carotenoids in this genotype were lower than those in LVK, R. Bras.…”