Effect of salinity on antioxidant responses of chickpea seedlings

Abstract

The changes in the activity of antioxidant enzymes, like superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase, and growth parameters such as length, fresh and dry weight, proline and H 2 O 2 contents, chlorophyll fluorescence (Fv/Fm), quantum yield of PSII and the rate of lipid peroxidation in terms of malondialdehyde in leaf and root tissues of a chickpea cultivar (Cicer arietinum L. cv. Gökçe) under salt treatment were investigated. Plants were subjected to 0.1, 0.2 and 0.5 M NaCl treatments for 2 and 4 days. Compared to controls, salinity resulted in the reduction of length and of the fresh and dry weights of shoot and root tissues. Salinity caused significant (P < 0.05) changes in proline and MDA levels in leaf tissue. In general, a dose-dependent decrease was observed in H 2 O 2 content, Fv/Fm and quantum yield of photosynthesis under salt stress. Leaf tissue extracts exhibited three activity bands, of which the higher band was identified as MnSOD and the others as FeSOD and Cu/ZnSOD. A significant enhancement was detected in the activities of Cu/ZnSOD and MnSOD isozymes in both tissues. APX and GR activities exhibited significant increases (P < 0.05) in leaf tissue under all stress treatments, whereas no significant change was observed in root tissue. The activity of CAT was significantly increased under 0.5 M NaCl stress in root tissue, while its activity was decreased in leaf tissue under 0.5 M NaCl stress for 4 days. These results suggest that CAT and SOD activities play an essential protective role against salt stress in chickpea seedlings.

Biochemical responses of Hyacinth bean (Lablab purpureus) to salinity stress

“…Nevertheless, levels of CAT and isozyme pattern in roots indicated a probable role for the enzyme in detoxification of ROS. This kind of increased POX and GR associated with decreasing CAT in leaves has been reported from chickpea (Eyidogan and Oz 2007) and French bean (Nagesh Babu and Devaraj 2008). Contrary to this, elevated levels of POX in roots and enhanced levels of GR, POX, and CAT observed in lentils suggested better protection of root system against salt.…”

“…Higher levels of GSH, GR and ascorbic acid, which coincided with enhanced levels of POX, further suggested that GR activity provided the reductant (reduced ASC), necessary for POX to reduce H 2 O 2 under salinity stress of up to 400 mM. A similar trend in POX and GR has been reported from chickpea stressed with NaCl (Eyidogan and Oz 2007). Only a marginal increase in POX up to 200 mM and steady decline in GR indicated that the combination of the two enzymes do not contribute to reduction of H 2 O 2 in roots, which is 7-8 times higher than leaf.…”

“…Gradual increase in proline in leaves of hyacinth bean reflected the fact that increasing concentration of NaCl has caused considerable osmotic effect, and the plant employs proline as an osmoprotectant. Such responses have been observed in variety of leguminous plants, including pea (Bandeoglu et al 2004) and chickpea (Eyidogan and Oz 2007) under salt stress. Proline biosynthesis and accumulation bears a direct correlation with carbohydrate levels and is related to acquisition of salt tolerance in plants (Hare and Cress 1997).…”

Comparison of ROS formation and antioxidant enzymes in Cleome gynandra (C4) and Cleome spinosa (C3) under drought stress

“…Our results agree with those of Sharma and Dubey [59], who observed increases in GR activity for Oryza sativa seedlings subjected to drought stress. Increases in GR activity under stresses of salt, Cd and Cu +2 were also observed in Capsicum annuum and C. orientinum [60,61]. The enhanced activity of GR might assist the regeneration of NADPH to NADP, thereby ensuring the availability of NADP to accept electrons from the photosynthetic electron transport chain [62].…”

Morpho-physiological variations in response to NaCl stress during vegetative and reproductive development of rice

“…4). Loss of chlorophyll pigment (Bahaji et al 2002;Siringam et al 2009) and reductions in the F v /F m ratio under salinity stress were also reported for other rice cultivars (Abdullah et al 2001;Cha-um et al 2007;Djanaguiraman et al 2006;Siringam et al 2009;Yamane et al 2008) as well as in sorghum (Netondo et al 2004), naked oat (Zhao et al 2007), wheat (Zheng et al 2009) and chickpea (Eyidogan and Ö z 2007).…”