Oxidative stress in five wheat varieties (Triticum aestivum L.) exposed to water stress and study of their antioxidant enzyme defense system, water stress responsive metabolites and H2O2 accumulation

Abstract

Five varieties of wheat (Triticum aestivum L.) -KW, UP 2752, PBW 343, SO and LV -were subjected to water stress and sampling was done on the 3 rd , 6 th and 9 th day of stress. RWC decline in KW, UP 2752 and PBW 343 (36.65, 42.34 and 40.75% respectively) was comparatively lesser than in LV and SO (52.93 and 52.67% respectively). In all varieties tested, three antioxidant enzymes (POX, APOX and GR) showed an initial increase. The activity of POX and GR increased with the increase in the duration of stress in KW, UP 2752 and PBW 343, while the activity of APOX declined. However, CAT and SOD showed an initial increase in these varieties, whereas it declined in SO and LV with increase in the period of stress. Accumulation of H 2 O 2 declined during prolonged water stress in KW, UP 2752 and PBW 343, while it increased in LV and SO. The accumulation of MDA content was three times higher in susceptible varieties than in tolerant varieties. The content of proline, phenol and ascorbate increased during water stress whereas the accumulation of carotenoid showed a significant decrease after showing an initial increase in the tested varieties. Higher values of total antioxidant and MSI were recorded in KW, UP 2752 and PBW 343 during stress while after 6 days MSI declined in LV and SO. During water stress there was a general decline in the total chlorophyll content. Analyzing the data, the present work suggested that out of the five varieties, KW, UP 2752 and PBW 343 showed more tolerance to water stress than SO and LV.Keywords: antioxidants, carotenoids, drought, lipid peroxidation.Abbreviations: APOX: ascorbate peroxidase (EC.1.11.1.11); CAT: catalase (EC.1.11.1.6); CMS: cell membrane stability; DAB: diaminobenzidine; EC: electrical conductivity; GR: glutathione reductase (EC 1.6.4.2); H 2 O 2 : hydrogen peroxide; KW: Kaweri; LV: local variety; MDA: malondialdehyde; MSI: membrane stability index; NBT: nitro blue tetrazolium; PPO: polyphenol oxidase; POX: peroxidase (EC. 1.11.17); RH: relative humidity; ROS: reactive oxygen species; RWC: relative water content; SO: Sonalika; SOD: superoxide dismutase (EC 1.15.1.1); TBA: thiobarbituric acid; TCA: trichloroacetic acid.Oxidative stress in five wheat varieties (Triticum aestivum L.) exposed to water stress and study of their antioxidant enzyme defense system, water stress responsive metabolites and H 2 O 2 accumulation

Effect of Salinity Stress on Antioxidant Defense System of Niger (<i>Guizotia abyssinica</i> Cass.)

“…Progressive elevation in GPOX up to 300 mM NaCl in parallel to H 2 O 2 levels appears to contribute to salt tolerance in niger (Figure 1). The observed enzyme levels in Niger were in consonance with those of drought stressed Hyacinth bean [40] and varieties of wheat [41]. ROS scavenging by APX involves reduction of H 2 O 2 using ASC as electron donor.…”

Responses of pomegranate cultivars to severe water stress and recovery: changes on antioxidant enzyme activities, gene expression patterns and water stress responsive metabolites

“…Under severe water stress, lipid peroxidation of cell membranes might lead to structural alterations in their integrity and stability (Reddy et al 2004). Chakraborty and Pradhan (2012) found that MDA content was lower in the leaves of drought tolerant Triticum aestivum L. than that in susceptible varieties. Our data indicate that the levels of membrane lipid peroxidation were relatively less in 'Ghojagh' and 'Rabab' cultivars under severe drought stress.…”

“…Reports on antioxidant enzyme activities under water deficit conditions are heterogeneous. Levels of these antioxidants have been shown to differentially alter, that is, they may be increased, remain unchanged or even decreased (Abedi and Pakniyat 2010;Chakraborty and Pradhan 2012;Gholami et al 2012;Liu et al 2011;Slabbert and Krüger 2014;Sun et al 2013;Türkan et al 2005). The study of expression patterns of genes encoding antioxidant enzymes could be valuable for understanding molecular adaptation of plant to drought stress conditions.…”

Boron Supply and Water Deficit Consequences in Young Paricá (<i>Schizolobium parahyba</i> var.<i> amazonicum</i>) Plants

“…These increases detected has the aim to improve the protection of cell structures against B toxicity (Keles et al, 2004), and in the case of the isolated effect of water deficit, the ASC accumulation can be explained by the ASC-GSH cycle, which is a predominant mechanism of ROS detoxification (Chakraborty and Pradhan, 2012). Cervilla et al (2007) observed that elevated B concentrations promoted an increase in ASC in study using Solanum lycopersicum plants, and Hussein and Khursheed (2014) observed that water deficit caused an increase in ASC of Triticum aestivum, corroborating this study.…”