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Showing 6 results for Water Deficit
Variations of Root and Shoot Tropane Alkaloids Production of Hyoscyamus niger under Two Rhizobacteria Strains Inoculation and Water Deficit Stress
M Ghorbanpour, N Majnoun Hoseini , Sh Rezazadeh, M Omidi, K Khavazi, M Hatami,
year 10, Issue 40 (12-2011)
Abstract
Background: Plants infection with microorganisms as well as physical factors such as osmotic stresses induced particular secondary metabolite pathways. Objectives: To investigate the growth promoting effects of two Rhizobacteria strains including Pseudomonas fluoresces (PF) and Putida (PP) in combination with application of water deficit stress on plant biomass of Hyoscyamus niger young roots and variation of tropane alkaloids content and yield in root and shoot parts. Methods: Two grams of dried each shoot and root samples was added to appropriate volume of CHCl3: MeOH: NH4OH 25%, (15:5: 1), and sonicated for 20 min. Alkaloids extracted were analyzed by gas chromatographic (GC) method using a Younglin Acme 6000 GC system equipped with a flame ionization detector (FID) and HP-5MS capillary column (30 m × 0.25 mm, film thickness 0.25 µm). The identification of alkaloids was based on the comparison of their GC retention time and mass spectra data with their standards substances. Results: Results indicated that the highest alkaloid content values in root (hyoscyamine: 0.26% DW scopolamine: 0.12% DW) and shoot (hyoscyamine: 0.85% DW scopolamine: 0.48% DW) were achieved in PF-187 treated plants grown under severe water stress conditions (W3). By contrast, the maximum alkaloid yield in root (hyoscyamine: 1.92 mg.plant-1 scopolamine: 0.83 mg.plant-1) and shoot (hyoscyamine: 5.88 mg.plant-1 SCO: 3.06 mg.plant-1) were obtained in PP-168 treated plants under low water stress conditions (W1). Conclusion: Rhizobacteria strains can function as environmentally sound tools to increase alkaloids production and counteract growing problems under stress conditions, especially by auxin production.

Two Main Tropane Alkaloids Variations of Black Henbane (Hyoscyamus niger) Under PGPRs Inoculation and Water Deficit Stress Induction at Flowering Stage
M Ghorbanpour, R Ghafarzadegan , K Khavazi , M Hatami ,
year 12, Issue 45 (2-2013)
Abstract
Background: Plants infection with microorganisms as well as physical factors such as osmotic stresses especially drought stress induced particular secondary metabolite production. Objective: Plant root and shoot hyoscyamine (HYO) and scopolamine (SCO) variations were investigated under three water deficit stress (WDS) levels as 30 (W1), 60 (W2) and 90 % (W3) water depletion of field capacity and Pseudomonas putida (PP) and P. fluoresence (PF) strains inoculation at flowering stage. Methods: Seedling radicles and culture media were inoculated with PP and PF (109 CFU/ml) strains. Monitoring of soil moisture levels was conducted using gravimetric method. Alkaloids extracted were identified by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Results: Results revealed that HYO was the prevalent alkaloid in root and shoot organs. The highest ratio of SCO to HYO (0.53) and the highest alkaloids both HYO and SCO content in root and shoot was observed in W3PF treatment. The largest total alkaloids (HYO+SCO) yield (25.7 mg.plant-1) was showed in PP treated plants under W1 conditions. Conclusion: Integrative use of effective Pseudomonades strains and WDS sounds to be an encouraging and eco-friendly strategy for increasing tropane alkaloids yield and content in Hyoscyamus niger root and shoot parts.

Effect of Multi-Walled Carbon Nanotubes on Physiological Traits, Phenolic Contents and Antioxidant Capacity of Salvia mirzayanii Rech. f. & Esfand. under Drought Stress
, , , ,
year 16, Issue 62 (5-2017)
Abstract

Background: Environmental stresses and biotic and abiotic elicitors induce secondary metabolites biosynthesis and hypersensitive response in plants through activation of defense mechanisms.  

Aim: This study was carried out with the aim of assessing the effects of different drought stress and multi-walled carbon nanotubes (MWCNTs) levels on physiological variations, flavonoid and phenolic contents, and antioxidant capacity of Salvia mirzayanii.

Methods: This study was arranged in a factorial experiment based on randomized complete block design under research greenhouse of medicinal plants department at Arak University. The first factor was considered as drought stress in 4 levels including 100, 75, 50 and 25% of field capacity (FC), and the second factor was designated as foliar spray of MWCNTs (functionalized and non- functionalized) at 4 different concentrations (0, 50 and 200 mg/L for functionalized MWCNTs, and 50 mg/L for non- functionalized MWCNTs).

Results: Results showed that drought stress and MWCNTs and their interactions significantly affected some studied traits. Leaf relative water content (p < 0.01) and chlorophyll index (p < 0.05) was significant under drought stress treatment, however, electrolyte leakage index significantly (p < 0.01) changed under different levels of MWCNTs. Furthermore, total phenolics was significantly (p < 0.01) changed under interaction of experimental treatments. The highest and the lowest phenolics content were achieved in functionalized MWCNTs exposed plants at 50 and 200 mg/L under 25% of FC, respectively. Maximum antioxidant activity was observed in extract originated from plants simultaneously treated with functionalized MWCNTs at 50 mg/L and drought stress at level of 25% FC. 

Conclusion: Application of functionalized MWCNTs at concentration of 50 mg/L along with moderate drought stress improved physiological traits and antioxidant activity of extract in S. mirzayanii plants.


Expression of Genes 1-deoxy-D-xylulose 5-phosphate Reductoisomerase (DXR), Sabinen Synthase (Tctps1) and α- terpineol Synthase (Tctps5) and its Relation to Thymol and Carvacrol Biosynthesis in Thymus vulgaris under Water Deficit Stress
F Mirzaei, F Fatehi, A Ismaili, A Yaghotipoor, A Qaderi,
year 16, Issue 64 (11-2017)
Abstract
Background: Thymol and Carvacrol are the two important secondary metabolites from Thymus vulgaris that productions of them are controlled by genetic and environmental factors.
Objective: Evaluation of Water stress effects on expression of three important genes of thymol and carvacrol biosynthetic pathway and also physiological and phytochemical properties of Thymus vulgaris.
Methods: The present study was conducted in a randomized complete block design with 4 treatments and 3 replications in Institute of Medicinal Plants, ACECR, Karaj. 
For this purpose, the treatments were selected as control (FC), 70% of FC, 40% of FC, and 20% of FC. Gene expression was studied using real-time PCR method, and HPLC was applied to essence analysis. Also physiological characteristic including chlorophyll content, relative water content, electrolyte leakage percentage and carotenoids content were analyzed.
Results: The results revealed that water stress significantly influenced the gene expression
(P≤ 0.05). The highest gene expression of DXR and Tctps5 was observed in 70% of FC, while the highest one of TvTPS1 was recorded in 40% of FC. Moreover, the maximum thymol and carvacrol was found in 70% of FC. In other hand the highest chlorophyll content and corotenoids content were obtained in 100% and 70% of FC respectively. Also there were not significant differences between treatments for  relative water content and electrolyte leakage percentage.
Conclusion: The 70% of FC through influencing of genes in the firs and last of MEP pathway increased thymol and carvacrol production.
 
Influence of Drought Stress, Biofertilizers and Zeolite on Morphological Traits and Essential Oil Constituents in Dracocephalum moldavica L.
Kh Karimzadeh Asl, M Ghorbanpour , M Marefatzadeh Khameneh , M Hatami ,
year 17, Issue 67 (9-2018)
Abstract
Background: Essential oil content and composition in medicinal and aromatic plants is highly affected by both biotic and abiotic factors.
Objective: To investigate the effects of drought stress, zeolite and bio-fertilizers on morphological characteristics and essential oil constituents in Dracocephalum moldavica L.
Methods: This experiment was conducted in the form of split factorial based on randomized complete block design with three replications in two years (2014 and 2015). The factorial experimental treatment was three levels of soil moisture (90%, 60% and 30%FC) applied to main plot, while application of zeolite (0 and 2 g per kg of soil) and bio-fertilizers (control, nitroxin, phosphate barvar-2 and nitroxin×phosphate barvar-2) were applied to sub plots.
Results: Application of zeolite had the highest effect on plant height, leaf area, dry matter and flowering top branches yield (FTBY) in 90%FC and essential oil percentage and yield in 60%FC. Similarly, combination of nitroxine+phosphate barvar-2 caused maximum value of plant height, leaf area, dry matter and FTBY in 90% FC and essential oil percentage and yield in 60%FC. The GC-MS analysis of the essential oil identified 14 compounds including ester and non ester combinations. The main compounds of ester combinations were geranyl acetate and neryl acetate and the main compounds of non ester combinations were neral, geraniol and geranial. The maximum percentage of ester and non ester combinations produced in 30%FC and 60-90%FC, respectively.
Conclusion: Application of zeolite accompanied by combination of nitroxine+phosphate barvar-2 produced the highest value of examined traits in D. moldavica L.
 

Effect of Seed Priming with Nanosilicon on Morpho-Physiological Characterestics, Quercetin Content and Antioxidant Capacity in Calendula officinalis L. under Drought Stress Conditions
Saeedeh Rahimi, Mehrnaz Hatami, Mansour Ghorbanpour,
year 18, Issue 72 (12-2019)
Abstract
Background: Silicon is the second most structural element in the earth, which in plants, in induces physiological processes and causes resistance to biotic and abiotic stresses as well.
Objective: The effect of seed priming with nanosilicon under different levels of drought stress on morphological, physiological, total phenol and flavonoid contents, quercetin levels and antioxidant capacity of the Calendula officinalis L.
Method: This study was conducted as factorial experiment in a randomized complete block design (RCBD) under four levels of drought stress (25, 50, 75 and 100 %FC), and different concentrations (0, 100, 200 and 500 mg/L) of silicon nanoparticles was considered as seed priming treatment.
Results: The results showed that drought stress levels and seed priming with nanosilicon at the various concentrations caused significant changes (P < 0.05) on measured traits of plant. The highest antioxidant activity of the obtained extract was observed in plants pretreated with nanosilicone at 200 mg/L under 25 %FC. Drought stress at moderate level (50 %FC) along with seed priming with nanosilicone at 100 mg /L had the highest effect on quercetin content. Furthermore, the highest and the lowest content of total flavonoid was observed in plants pretreated with silicon nanoparticles at 200 mg/L and control (without priming) under drought stress at 25 %FC, respectively.
Conclusion: Applicationof nanosilicone at lower concentrations (100-200 mg/L) and drought stress at 50 %FC may improve plant physiological and metabolite indices in marigold.

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