Antioxidant and carbohydrate changes of two pomegranate cultivars under deficit irrigation stress

Abstract

The purpose of this study was to evaluate the biochemical responses to water stress tolerance of two pomegranate cultivars, 'Rabbab' and 'Shishehgap'. After the establishment of rooted stem cuttings of both cultivars under greenhouse conditions, they were treated with four levels of deficit irrigations (100%, 75%, 50% and 25% of field capacity) in a completely randomized design with four replications. The results showed a significant difference between the two cultivars regarding antioxidant enzymes activities. In both cultivars, the water stress increased the activity of superoxide dismutase, catalase and ascorbate peroxidase. However, at high water deficit (25% field capacity, FC), 'Rabbab' showed significantly higher enzyme activity than 'Shishehgap'. In each level of irrigation, there were not considerable differences in peroxidase activity between the two cultivars. An increment of 162% and 65.5% in soluble sugar was gained at 50% FC in 'Rabbab' and 'Shishehgap', respectively. 'Rabbab' showed better growth performance in each level of irrigation than 'Shishehgap'. Therefore, it can be concluded that 'Rabbab', with lesser decline in leaf relative water content (RWC), a strong antioxidant system and accumulation of more soluble carbohydrates, can resist higher water stress than 'Shishehgap'.Additional key words: field capacity; enzyme activity; Punica granatum L.; water stress. Abbreviation used: APX (ascorbate peroxidase); CAT (catalase); DW (dry weight); FC (field capacity); FW (fresh weight); NBT (nitro blue tetrazolium); POD (peroxidase); ROS (reactive oxygen species); RWC (leaf relative water content); SOD (superoxide dismutase).

Pomegranate (Punica granatum L.) Fruits: Characterization of the Main Enzymatic Antioxidants (Peroxisomal Catalase and SOD Isozymes) and the NADPH-Regenerating System

“…Contemporary works that applied 2-D/LC/MS (2-D/Liquid Chromatography/Mass Spectrometry) and HPLC/MS (High Performance Liquid Chromatography/Mass Spectrometry) approaches reported a battery of proteins including class III-chitinases, selenium-binding proteins, anthocyanidin synthase, chalcone synthase, cinnamyl alcohol dehydrogenase and flavonol 3-O-glucosyltransferase and other non-storage proteins [30,57,58]. Later, other proteins related to ROS and secondary metabolism were reported [19][20][21][22][23][24]. Thus far, although the new throughput approaches (mainly iTRAQ and RNA-seq) are contributing to increasing knowledge on the background of pomegranate metabolism [30][31][32][33][34][35], more research is necessary since these technologies provide data on the gene transcript levels and their corresponding translational products, respectively.…”

“…This relevance is also supported by the detection of peroxisomal catalase activity in this plant material. CAT, which is the main H 2 O 2 scavenging system in plants, has been used in the same situations given above for pomegranate SOD [19][20][21][22][23][24]. However, unlike SOD, CAT was detected in both seed extracts and juice.…”

Acid rain-induced oxidative stress regulated metabolic interventions and their amelioration mechanisms in plants

“…Moreover, Fe 2+ becomes more soluble at lower pH, and in presence of Fe 2+ most of the H 2 O 2 is readily converted into highly reactive hydroxyl radical (OH . ) by Haber-Weiss reaction (Ebtedaie & Shekafandeh 2016).…”