Vahideh Khaleghnezhad

Bio: Vahideh Khaleghnezhad is an academic researcher from University of Zanjan. The author has contributed to research in topics: Dracocephalum moldavica & Abscisic acid. The author has an hindex of 2, co-authored 3 publications receiving 22 citations.

Concentrations-dependent effect of exogenous abscisic acid on photosynthesis, growth and phenolic content of Dracocephalum moldavica L. under drought stress.

Abstract: The drought conditions and the application of ABA reduce the photosynthetic activity, and the processes related to the transpiration of Dracocephalum moldavica L. At the same time, the plant increases the production of phenolic compounds and essential oil as a response to stress conditions. In the semi-arid regions, drought stress is the most important environmental limitations for crop production. Abscisic acid (ABA) plays a crucial role in the reactions of plants towards environmental stress such as drought. Field experiments for two consecutive years in 2016 and 2017 were conducted to evaluate the effect of three watering regimes (well-watered, moderate and severe drought) and five exogenous ABA concentrations (0, 5, 10, 20 and 40 μM) on growth, photosynthesis, total phenolic and essential oil content of Dracocephalum moldavica L. Without ABA application, the highest photosynthetic rate (6.1 μmol CO2 m−2 s−1) was obtained under well-watered condition and, moderate and severe drought stress decreased photosynthesis rate by 26.39% and 34.43%, respectively. Some growth parameters such as stem height, leaf area, leaf dry weight and biological yield were also reduced by drought stress. ABA application showed a decreasing trend in photosynthesis rate and mentioned plant growth parameters under all moisture regimes. The highest seed yield (1243.56 kg ha−1) was obtained under well-watered condition without ABA application. Increasing ABA concentration decreased seed yield in all moisture regimes. The highest total phenolic content (8.9 mg g−1 FW) and essential oil yield (20.58 kg ha−1) were obtained from 20 and 5 μM ABA concentration, respectively, under moderate drought stress.

Co-inoculation with Mesorhizobium ciceri and PGPR can improve chickpea (Cicer arietinum L.) growth in rain-fed and irrigated conditions

Abstract: An experiment was conducted to evaluate the effect of co-inoculation with Rhizobium and plant growth promoting rhizobacteria (PGPR) on chickpea growth under rain-fed and irrigated conditions. Treatments included inoculation with PGPR, co-inoculation with two strain of Mesorhizobium ciceri (SWRI3 and SWRI17), co-inoculation with SWRI3+SWRI17, co-inoculation with PGPR+SWRI3+SWRI17 and application of 25 kg nitrogen ha-1 and no fertilizing as a control. Growth components analysis was estimated from growth curves fitted to the relationships between the measured variables and the temperature index measured based on growing degree days. Drought stress due to rainfed condition, caused significant reduction in crop growth parameters; however, bio-fertilizer improved growth significantly. The maximum LAI in the rainfed condition was 0.29 while co-inoculation with PGPR+SWRI3+SWRI17increased it to 0.54. Although, bio-fertilizers increased the time chickpea plants needed to reach their maximum LAI. In the irrigated condition, the highest CGR, TDM and seed yieldirrigated conditionwere 0.42 g m-2 d-1, 32.34g and 2335 kg ha-1 respectively and decreased to 0.23 g m-2 d-1, 18.34g and 1438 kg ha-1 respectively in rain-fed condition that were also obtained from co-inoculation with all bio-fertilizers (PGPR+SWRI3+SWRI17) in both conditions. Overall, results suggest that using bio-fertilizer helps to alleviat drought stress in rainfed condition and could be recommended in semi-arid environment to maximize chickpea yield.

Phytochemical Analysis and Anti-Inflammatory Activity of Different Ethanolic Phyto-Extracts of Artemisia annua L.

Abstract: Artemisia annua L. (AA) has shown for many centuries important therapeutic virtues associated with the presence of artemisinin (ART). The aim of this study was to identify and quantify ART and other secondary metabolites in ethanolic extracts of AA and evaluate the biological activity in the presence of an inflammatory stimulus. In this work, after the extraction of the aerial parts of AA with different concentrations of ethanol, ART was quantified by HPLC and HPLC-MS. In addition, anthocyanins, flavanols, flavanones, flavonols, lignans, low-molecular-weight phenolics, phenolic acids, stilbenes, and terpenes were identified and semi-quantitatively determined by UHPLC-QTOF-MS untargeted metabolomics. Finally, the viability of human neuroblastoma cells (SH-SY5Y) was evaluated in the presence of the different ethanolic extracts and in the presence of lipopolysaccharide (LPS). The results show that ART is more concentrated in AA samples extracted with 90% ethanol. Regarding the other metabolites, only the anthocyanins are more concentrated in the samples extracted with 90% ethanol. Finally, ART and all AA samples showed a protective action towards the pro-inflammatory stimulus of LPS. In particular, the anti-inflammatory effect of the leaf extract of AA with 90% ethanol was also confirmed at the molecular level since a reduction in TNF-α mRNA gene expression was observed in SH-SY5Y treated with LPS.

Variation in Phytochemical, Antioxidant and Volatile Composition of Pomelo Fruit (Citrus grandis (L.) Osbeck) during Seasonal Growth and Development.

Abstract: Citrus fruits exhibit a high level of different phytoconstituents, of which the changes in the different parts of the fruit during ripening have not been thoroughly studied yet. Thus, in this study, we have investigated how different parts of pomelo fruit (Citrus grandis L.) are modified throughout the development of two consecutive growing seasons. In detail, the main phytochemical compounds, such as total phenolic content, total flavonoid content, antioxidant capacity, DPPH free radical scavenging activity, Ferric reducing antioxidant power (FRAP), and naringin and tannin content, were analyzed. A systematic metabolism of these compounds was found during the development of the fruit, but some pomelo tissues showed a fluctuating trend, suggesting a dependence on the different growing season. Focusing on the tissue distribution of these compounds, the fruit membrane contained the highest level of total phenolic and flavonoid content; fruit flavedo displayed the highest antioxidant capacities and FRAP activities, whereas maximum accumulation of naringin was noticed in fruit albedo. Instead, the highest DPPH free radical scavenging activity and tannin contents were found in the pomelo juice. Regarding the distribution of compounds, a possible bias pattern for the accumulation of those compounds has been noticed throughout the fruit development. From the GC-MS analysis, a total of 111 compounds were identified, where 91 compounds were common in both seasons. Overall, these results could be useful for the food processing industry as guidelines for excellent quality foods and for introducing health-beneficial products and components into our daily diets.

Abscisic acid signaling reduced transpiration flow, regulated Na+ ion homeostasis and antioxidant enzyme activities to induce salinity tolerance in wheat (Triticum aestivum L.) seedlings

Abstract: Salinity, one of the catastrophic abiotic stresses that uces wheat production around the globe. Abscisic acid (ABA) is a stress phytohormone as a signaling molecule that led us to investigate its potential to improve morpho-physiological characteristics, antioxidant metabolism, and ion homeostasis in wheat (Triticum aestivum L.) seedlings grown under salinity stress (0, 50, and 100 mM NaCl). The findings suggested that salt-induced toxicity significantly (P + ion accumulation and uptake in wheat leaf and root tissues with the increasing NaCl concentration in the nutrient media. However, root-zone supply of ABA (0, 5, and 10 μ M) prominently alleviated salt induced phytotoxicity. The 10 μ M concentration of ABA promoted shoot (81.7%) and root (102.1%) dry weight, root length (38.2%), Chl. a (65.3%), Chl. b (149.0%), carotenoids (95.7%) and membrane damage (36.7%) when NaCl was added at 100 mM, relative to the corresponding treatment without ABA. Moreover, ABA (10 μ M) supply decreased Na + ion uptake (root to leaf) due to reduced transpiration rate (81.1%), and thereby ameliorated oxidative injury by ucing leaf malondialdehyde (MDA) and H 2 O2 contents by 36.8% and 29.9%, respectively, at 100 mM NaCl stress, relative to the similar treatment without ABA. In addition, the activities of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) were upregulated by 143.9%, 20.2%, and 19.5% in leaves and by 144.9%, 23.4% and 41.1% in roots respectively, with 10 μ M ABA application under 100 mM salinity stress, compa to the 100 mM NaCl treatment without ABA. Conclusively, this study proposed that root-zone ABA application promoted salinity tolerance in wheat seedlings and could be a practical approach for wheat production in salt-affected regions to ensure food security.