Long term salinity stress in relation to lipid peroxidation, super oxide dismutase activity and proline content of salt-sensitive and salt-tolerant wheat cultivars

Abstract

Salinity is a widespread root medium problem limiting productivity of\ncereal crops worldwide. The ability of plants to tolerate salt is\ndetermined by multiple biochemical pathways that facilitate retention\nand/or acquisition of water, protect chloroplast functions, and\nmaintain ion homeostasis. Therefore, the ability of salt-sensitive\n('Tajan') and salt-tolerant cultivar ('Bam') of Triticum aestivum L.\nto adapt to a saline environment were evaluated in a set of greenhouse\nexperiments under salt stress during three growth stages (tillering,\n50% anthesis, and 10 d after anthesis). Plants were irrigated by\ndifferent saline waters with electrical conductivities of 1.3, 6, 8,\n10, and 12 dS m-1, which were obtained by adding NaCl:CaCl2 in 10:1\nmolar ratio to fresh water. Differences in growth parameters, lipid\nperoxidation, superoxide dismutase (SOD) activity, and proline\naccumulation were tested in order to put forward the relative tolerance\nor sensitivity of cultivars. Results indicated that both parameters\ndiffer according to the cultivar's ability in coping oxidative stress\ncaused by salinity. We observed a greater decline in the growth\nparameters and grain yield under salt stress in 'Tajan' than in 'Bam'.\nMalondialdehyde content was also higher in 'Tajan'. The improved\nperformance of the 'Bam' under high salinity was accompanied by an\nincrease in SOD (EC 1.15.1.1) activity and proline content at all\ngrowth stages. Growth parameters, lipid peroxidation and proline\naccumulation results are also in good correlation with supporting this\ncultivar is being relatively tolerant.