Hydrogen peroxide generation and antioxidant enzyme activities in the leaves and roots of wheat cultivars subjected to long-term soil drought stress

Abstract

The dynamics of the activity of catalase, ascorbate peroxidase, guaiacol peroxidase, and benzidine peroxidase, as well as the level of hydrogen peroxide in the vegetative organs of durum wheat (Triticum durum Desf.) cultivars was studied under long-term soil drought conditions. It was established that hydrogen peroxide generation occurred at early stages of stress in the tolerant variety Barakatli-95, whereas in the susceptible variety Garagylchyg-2 its significant amounts were accumulated only at later stages. Garagylchyg-2 shows a larger reduction of photochemical activity of PS II in both genotypes at all stages of ontogenesis under drought stress than Barakatli-95. The highest activity of catalase which plays a leading role in the neutralization of hydrogen peroxide was observed in the leaves and roots of the drought-tolerant variety Barakatli-95. Despite the fact that the protection system also includes peroxidases, the activity of these enzymes even after synthesis of their new portions is substantially lower compared with catalase. Native PAGE electrophoresis revealed the presence of one isoform of CAT, seven isoforms of APX, three isoforms of GPO, and three isoforms of BPO in the leaves, and also three isoforms of CAT, four isoforms of APX, two isoforms of GPO, and six isoforms of BPO in the roots of wheat. One isoform of CAT was found in the roots when water supply was normal and three isoforms were observed under drought conditions. Stress associated with long-term soil drought in the roots of wheat has led to an increase in the heterogeneity due to the formation of two new sedentary forms of catalase: CAT2 and CAT3.

Pigments photosynthétiques, enzymes antioxydantes et potentiel osmotique foliaire de dix génotypes de blé dur (Triticum durum) : effet du stress hydrique

“…Les résultats obtenus par la séparation des isoenzymes de CAT sont présentés à la figure 5. Une seule zone de migration a été détectée chez les plantes témoins et stressées avec une faible mobilité électrophorétique, ce qui correspond aux données de la littérature (Huseynova et al 2015;Nabizadeh et al 2015). Chez les plantes témoins, la zone d'activité enzymatique était représentée par deux bandes, dont une majeure.…”

Interspecific differences of antioxidant ability of introduced Chaenomeles species with respect to adaptation to the steppe zone conditions

“…The functioning of catalase is the main metabolic pathway to protect the photosynthetic process, eliminating excess hydrogen peroxide, which is formed in plant cells under the influence of unfavourable environmental conditions (Huseynova et al, 2015). The effect of drought, high temperature and intense sunlight on plants reduces the effectiveness of photosynthesis, instead reinforcing the process of photorespiration and causing excessive accumulation of reactive oxygen species, including hydrogen peroxide (Luna et al, 2005).…”

Virus-induced changes in photosynthetic parameters and peroxidase isoenzyme contents in tomato (Solanum lycopersicum L.) plants

“…Organic radicals (R • ) produced under the influence of different stressors immediately react to oxygen molecules forming peroxide radicals (RO 2 • ), which in turn react to unsaturated lipids and form organic peroxides and new radicals. In other words, peroxidation of lipids occurs, the main indicator of which is the increase in the MDA amount (Huseynova et al 2015). The amount of peroxide groups is considered to be one of the main markers of the oxidative stress in plants.…”