scholarly journals Foliar application of melatonin induces tolerance to drought stress in Moldavian balm plants (Dracocephalum moldavica) through regulating the antioxidant system

2018 ◽  
Vol 30 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Rozita Kabiri ◽  
Ali Hatami ◽  
Hakimeh Oloumi ◽  
Mehdi Naghizadeh ◽  
Fatemeh Nasibi ◽  
...  
Keyword(s):  
Drought Stress ◽  
Foliar Application ◽  
Leaf Length ◽  
Stress Conditions ◽  
Guaiacol Peroxidase ◽  
Severe Drought ◽  
Wide Range ◽  
Significant Difference ◽  
Relative Water ◽  
Leaf Surface Area

Abstract Melatonin, as an indoleamine molecule, regulates a wide range of physiological functions during the growth, morphogenesis and response of plants to biotic and abiotic stresses. In this research, the effect of exogenous application of melatonin (0 (distilled water), 50, 100 and 150 µM) to the leaves of Moldavian balm plants grown under different levels of drought stress (100% (control), 80%, 60% and 40% of field water capacity) was investigated. The results indicate that plants which were treated with 100 µM melatonin showed the greatest leaf surface area, lateral branching, flower length and activities of antioxidant enzymes (superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase). Foliar application of 100 µM melatonin had no significant difference in catalase activity in comparison with the control and other concentrations of melatonin under normal, moderate and severe drought stress conditions. The lowest H2O2 content and lipid peroxidation (electrolyte leakage, concentrations of malondialdehyde and other aldehydes) were obtained at the concentration of 100 µM melatonin under severe drought stress. This concentration also significantly increased the chlorophyll content and enhanced the relative water content; however, foliar application of 100 µM melatonin had no significant effect on leaf length and proline content compared with the control under normal and stress conditions. The obtained results suggested that foliar application of 100 µM melatonin was more effective than the concentrations of 50 and 150 µM melatonin in reducing the adverse effects of moderate and severe drought stress.

scholarly journals Biofertilizer Application Enhances Drought Stress Tolerance and Alters the Antioxidant Enzymes in Medicinal Pumpkin (Cucurbita pepo convar. pepo var. Styriaca)

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 588
Author(s):  
Solmaz Najafi ◽  
Hossein Nazari Nasi ◽  
Ruveyde Tuncturk ◽  
Murat Tuncturk ◽  
Riyaz Z. Sayyed ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Grain Yield ◽  
Cucurbita Pepo ◽  
Stress Conditions ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase ◽  
Severe Drought ◽  
Four Levels ◽  
Irrigation Levels

The effects of mycorrhiza, Thiobacillus and Nitroxin (Azotobacter and Azospirillum sp.) biofertilizers under drought stress conditions with four levels of field capacity (FC) (control(100%), 85%, 70%, and 50%) on the antioxidant enzyme activities of medicinal pumpkin (Cucurbita pepo convar. pepo var. Styriaca) were evaluated during the years 2018–2019. Irrigation levels exhibited significant effects on all studied variables, except for the catalase (CAT) enzyme. A significant correlation was observed between the effects of irrigation levels and biofertilizers on antioxidant enzymes, soluble protein content, and grain yield. The highest activity of catalase and ascorbate peroxidase (APX) enzymes was achieved using mycorrhiza in 50% FC. Increasing drought intensity and mycorrhiza stimulated glutathione reductase (GR) and guaiacol peroxidase (GPX) activities by 32% and 66%, while Nitroxin increased them by 16% and 43%, respectively. Under severe drought stress conditions, only mycorrhiza exhibited a positive effect on GR and GPX enzymes. Under moderate and severe drought stress conditions, Nitroxin increased grain yield by 13% and 12.6%, respectively. The irrigation regimes and bio-fertilizers had a significant effect on β-sitosterol percentage. The highest amount was observed at the highest level of drought stress. Among the various bio-fertilizers treatments, the application of Thiobacillus yielded the highest percentage of β-sitosterol. The results of the present study demonstrate that the application of biofertilizers is beneficial in coping with drought stress.

scholarly journals Variation in yield and biochemical factors of German chamomile (Matricaria recutita L.) under foliar application of osmolytes and drought stress conditions

2019 ◽  
Vol 8 (2) ◽  
pp. 90-100
Author(s):  
Farhad Masoudi Sadaghiani ◽  
Majid Amini Dehaghi ◽  
Alireza Pirzad ◽  
Mohammad Hossein Fotokian
Keyword(s):  
Drought Stress ◽  
Essential Oil ◽  
Protein Concentration ◽  
Foliar Application ◽  
Stress Conditions ◽  
Oil Yield ◽  
Severe Drought ◽  
Mild Stress ◽  
Severe Stress ◽  
Essential Oil Yield

Introduction: Chamomile is one of the oldest and most valuable medicinal plants from the Asteraceae family. In addition to pharmaceutical uses, its essential oil is extensively used in perfumery, cosmetics, food industry and aromatherapy. This experiment was conducted with the aim of investigating the effect of osmolytes foliar application on biochemical characteristics, and the yield of German chamomile under drought stress conditions. Methods: The experiment was conducted as a split plot with randomized complete block design with three replications during the 2016-2017 growing season. Three levels of irrigation, 50 (control), 100 (mild stress) and 150 mm (severe stress) evaporation from evaporation pan class A, and spraying treatments, NS (no-spraying), W (distilled water), MeJA (methyl jasmonate), SA (salicylic acid), HA (humic acid), GB (glycine betaine) and GABA (γ-aminobutyric acid) were considered as the main plots and sub-plots, respectively. Results: Analyzed data indicated that proline, total soluble sugars (TSS), and essential oil yield were enhanced with the increase of drought intensity and the maximum amount was registered under severe stress, while the severe drought caused a substantial reduction in protein concentration of leaves and dried flower yield. Proline concentration of leaves significantly increased with exogenously applied spraying treatments under severe drought. All spraying treatments except GB under severe stress, caused higher TSS concentration than those subjected to mild stress. SA, HA, and GABA treated plants had significantly higher protein concentration compared to NS treatment. Plants that treated with GABA had the highest dried flower and essential oil yield. Conclusion: The present study suggests that osmolytes foliar application can ameliorate the detrimental effects of drought on chamomile plant through alteration in yield and biochemical variables.

scholarly journals Heritability and mode of gene action determination for grain filling rate and relative water content in hexaploid wheat

Genetika ◽  
2012 ◽  
Vol 44 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ahmad Golparvar
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Relative Water Content ◽  
Stress Condition ◽  
Gene Action ◽  
Grain Filling ◽  
Stress Conditions ◽  
Filling Rate ◽  
Grain Filling Rate ◽  
Relative Water

Mode of gene action, heritability and determination of the effective breeding strategy for improvement of physiological and traits specifically in drought stress conditions is very important. Therefore, this study was conducted by using two drought susceptible and tolerant wheat cultivars. Cultivars Sakha8 (tolerant) and Pishtaz (susceptible) as parents along with F1, F2, BC1 and BC2 generations were sown in a randomized complete block design with three replications in drought stress conditions. Results of analysis of variance indicated significant difference between generations as well as degree of dominance revealed over-dominance for the both traits. Fitting simple additive-dominance model designated that this model was not able to account for changes of traits relative water content and mean of grain filling rate. It was revealed that m-d-h-i-j model for relative water content and m-d-h-i model for mean of grain filling rate are the best models. Estimation of heritability and mode of gene action indicated that selection for improvement of traits studied in stress condition and specifically in early generations have medium genetic gain. In conclusion, grain filling rate is better than relative water content as indirect selection criteria to improve plant grain yield in drought stress condition.

scholarly journals DEHYDRIN PROFILES OF SOME IRANIAN MELON VARIETIES (Cucumis melo L. Merr) UNDER DROUGHT STRE SS CONDITIONS

2019 ◽  
Vol 18 (6) ◽  
pp. 75-84
Author(s):  
Alireza Motallebi-Azar ◽  
István Papp ◽  
Anita Szegő
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Content ◽  
Water Status ◽  
Field Capacity ◽  
Total Protein Content ◽  
Severe Drought ◽  
Molecular Weights ◽  
Potential Marker ◽  
Relative Water

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.

scholarly journals Differential Activity of Antioxidant Enzymes and Physiological Changes in Wheat (Triticum aestivum L.) Under Drought Stress

2019 ◽  
Vol 11 (2) ◽  
pp. 266-276
Author(s):  
Kamal MIRI-HESAR ◽  
Ali DADKHODAIE ◽  
Saideh DOROSTKAR ◽  
Bahram HEIDARI
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Field Capacity ◽  
Triticum Aestivum L ◽  
Plant Production ◽  
Breeding Programs ◽  
Drought Tolerant ◽  
Severe Water Stress ◽  
Significant Difference ◽  
Relative Water

Drought stress is one of the most significant environmental factors restricting plant production all over the world. In arid and semi-arid regions where drought often causes serious problems, wheat is usually grown as a major crop and faces water stress. In order to study drought tolerance of wheat, an experiment with 34 genotypes including 11 local and commercial cultivars, 17 landraces, and six genotypes from International Maize and Wheat Improvement Center (CIMMYT) was conducted at the experimental station, School of Agriculture, Shiraz University, Iran in 2010-2011 growing season. Three different irrigation regimes (100%, 75% and 50% Field Capacity) were applied and physiological and biochemical traits were measured for which a significant difference was observed in genotypes. Under severe water stress, proline content and enzymes’ activities increased while the relative water content (RWC) and chlorophyll index decreased significantly in all genotypes. Of these indices, superoxide dismutase (SOD) and RWC were able to distinguish tolerant genotypes from sensitives. Moreover, yield index (YI) was useful in detecting tolerant genotypes. The drought susceptibility index (DSI) varied from 0.40 to 1.71 in genotypes. These results indicated that drought-tolerant genotypes could be selected based on high YI, RWC and SOD and low DSI. On the whole, the genotypes 31 (30ESWYT200), 29 (30ESWYT173) and 25 (Akbari) were identified to be tolerant and could be further used in downstream breeding programs for the improvement of wheat tolerance under water limited conditions.

scholarly journals Effects of Exogenous Salicylic Acid on Drought Response and Characterization of Dehydrins in Impatiens walleriana

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1589
Author(s):  
Dragana D. Antonić ◽  
Angelina R. Subotić ◽  
Milan B. Dragićević ◽  
Danijel Pantelić ◽  
Snežana M. Milošević ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Salicylic Acid ◽  
Drought Stress ◽  
De Novo ◽  
Foliar Application ◽  
Drought Response ◽  
Leaf Transcriptome ◽  
Relative Water ◽  
Impatiens Walleriana

Impatiens walleriana is a valued ornamental plant sensitive to drought stress. We investigated whether the foliar application of 2mM salicylic acid (SA) can protect potted I. walleriana plants from drought stress. The plants were divided into: watered plants, drought-stressed plants, watered plants treated with SA and drought-stressed plants treated with SA. The number of flowers and flower buds, relative water content (RWC), contents of malondialdehyde (MDA) and proline (Pro) and the activities of superoxide dismutases, catalases and peroxidases were recorded at different time points. Three dehydrin sequences were identified in de novo assembled leaf transcriptome: IwDhn1, IwDhn2.1 and IwDhn2.2. Drought stress caused wilting, floral abortion, reduction of RWC and increased MDA—an indicator of lipid peroxidation. In response to drought, Impatiens accumulated Pro and induced chloroplastic Cu/ZnSOD and two peroxidase isoforms. The most remarkable drought response was strong induction of IwDhn2.1 and IwDhn2.2. Rehydration restored RWC, Pro level, Cu/ZnSOD activity and dehydrins expression in drought-stressed plants approximately to the values of watered plants.SA had ameliorating effects on plants exposed to drought, including prevention of wilting, preservation of RWC, increased Pro accumulation, modulation of antioxidative activities and remarkable decrease of lipid peroxidation, but without effects on flowers’ preservation.

Antioxidant defences in olive trees during drought stress: changes in activity of some antioxidant enzymes

2005 ◽  
Vol 32 (1) ◽  
pp. 45 ◽  
Author(s):  
Adriano Sofo ◽  
Bartolomeo Dichio ◽  
Cristos Xiloyannis ◽  
Andrea Masia
Keyword(s):  
Drought Stress ◽  
Water Deficit ◽  
Active Oxygen Species ◽  
Net Photosynthesis ◽  
Cellular Damage ◽  
Guaiacol Peroxidase ◽  
Severe Drought ◽  
Antioxidant Defences ◽  
Stress Changes ◽  
Olive Trees

The effects of drought on the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD), indoleacetate oxidase (IAAox) and polyphenol oxidase (PPO) were studied in 2-year old Olea europaea L. (cv. ‘Coratina’) plants grown under high temperatures and irradiance levels and gradually subjected to a controlled water deficit. After 20 d without irrigation, mean predawn leaf water potential fell from –0.37 to –5.37 MPa, and decreases in net photosynthesis and transpiration occurred. The activities of SOD, APX, CAT and POD increased in relation to the severity of drought stress in both leaves and roots. In particular, a marked increase in APX activity was found in leaves of plants at severe drought stress. CAT activity increased during severe water deficit conditions in leaves and fine roots. The patterns of POD and IAA oxidase activity ran in parallel and showed increases in relation to the degree of drought. In contrast, PPO activity decreased during the progression of stress in all the tissues studied. The results show that the ability of olive trees to up-regulate the enzymatic antioxidant system might be an important attribute linked to drought tolerance. This could limit cellular damage caused by active oxygen species during water deficit.

scholarly journals Effect of Foliar Application with Salicylic Acid on Some Morphological and Physiological Characteristics of Sesame (Sesamum indicum L.) Under Drought Stress

2016 ◽  
Vol 49 (4) ◽  
pp. 35-42 ◽  
Author(s):  
A. Khatiby ◽  
F. Vazin ◽  
M. Hassanzadeh ◽  
A. Ahmadi Shadmehri
Keyword(s):  
Salicylic Acid ◽  
Water Stress ◽  
Drought Stress ◽  
Foliar Application ◽  
Morphological Characteristics ◽  
Interactive Effects ◽  
Area Index ◽  
Physiological Processes ◽  
Significant Difference ◽  
Four Levels

Abstract Drought is an important factor that could restrict plants growth and productivity through several biological and physiological processes. Salicylic acid (SA) has a key role in many physiological processes of plants and stimulate specific responses against various stresses biotic and abiotic, in some of plants. In order to evaluate the effect of foliar application by salicylic acid (SA) under drought stress on some morphological characteristics sesame, a split-plot experiment with a completely random design with three replications was performed. There were three levels of irrigation: control (normal irrigations), water stress at flowering stage and water stress at seed production stage, as main plot and sub plot consisting of four levels of the foliar application of salicylic acid: 0 (control), 1, 1.5 and 2.25 mM. Results indicated that the effects of water stress on traits, such as plant height, height of first capsule from soil surface, number of branches, number of capsules per plant showed significant difference at a level of 1%, while on the number of seeds per capsule, seed weight, leaf area index, biological yield, grain yield sesame, without significant difference indicated. Foliar application with salicylic acid was not so significant (P< 0.05) at different concentrations on measured traits, as well as interactive effects between drought stress and different amounts of salicylic acid, without significant difference observed.

Measurement of heat stress conditions at cow level and comparison to climate conditions at stationary locations inside a dairy barn

2016 ◽  
Vol 83 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Laura K Schüller ◽  
Wolfgang Heuwieser
Keyword(s):  
Heat Stress ◽  
Great Distance ◽  
Stress Conditions ◽  
Climate Conditions ◽  
Air Supply ◽  
Increased Risk ◽  
Climatic Environment ◽  
Wide Range ◽  
Significant Difference ◽  
Humidity Index

The objectives of this study were to examine heat stress conditions at cow level and to investigate the relationship to the climate conditions at 5 different stationary locations inside a dairy barn. In addition, we compared the climate conditions at cow level between primiparous and multiparous cows for a period of 1 week after regrouping. The temperature-humidity index (THI) differed significantly between all stationary loggers. The lowest THI was measured at the window logger in the experimental stall and the highest THI was measured at the central logger in the experimental stall. The THI at the mobile cow loggers was 2·33 THI points higher than at the stationary loggers. Furthermore, the mean daily THI was higher at the mobile cow loggers than at the stationary loggers on all experimental days. The THI in the experimental pen was 0·44 THI points lower when the experimental cow group was located inside the milking parlour. The THI measured at the mobile cow loggers was 1·63 THI points higher when the experimental cow group was located inside the milking parlour. However, there was no significant difference for all climate variables between primiparous and multiparous cows. These results indicate, there is a wide range of climate conditions inside a dairy barn and especially areas with a great distance to a fresh air supply have an increased risk for the occurrence of heat stress conditions. Furthermore, the heat stress conditions are even higher at cow level and cows not only influence their climatic environment, but also generate microclimates within different locations inside the barn. Therefore climate conditions should be obtained at cow level to evaluate the heat stress conditions that dairy cows are actually exposed to.

scholarly journals Water Deficit Irrigation Impacts on Antioxidant Metabolism Associated with Freezing Tolerance in Creeping Bentgrass

2015 ◽  
Vol 140 (4) ◽  
pp. 323-332 ◽  
Author(s):  
Li-Juan Zhang ◽  
Tian-Xiu Zhong ◽  
Li-Xin Xu ◽  
Lie-bao Han ◽  
Xunzhong Zhang
Keyword(s):  
Drought Stress ◽  
Cold Acclimation ◽  
Water Deficit ◽  
Freezing Tolerance ◽  
Deficit Irrigation ◽  
Creeping Bentgrass ◽  
Guaiacol Peroxidase ◽  
Severe Drought ◽  
Antioxidant Metabolism ◽  
Mild Drought

Soil water deficit impacts cold acclimation and freezing tolerance in creeping bentgrass (Agrostis stolonifera L.), but the mechanisms underlying have not been well understood. The objectives of this study were to investigate the effects of deficit irrigation before and during cold acclimation on osmoprotectants, antioxidant metabolism, and freezing tolerance in creeping bentgrass. The grass was subjected to three-soil moisture levels: well-watered [100% container capacity (CC)], deficit irrigation induced-mild drought stress (60% CC), and severe drought stress (30% CC) for 35 days including 14 days at 24/20 °C (day/night) and then 21 days under cold acclimation treatment (2 °C) in growth chambers. Leaf proline and total soluble sugar (TSS) levels were higher in the grass under mild drought stress relative to that under severe drought stress. Superoxide (O2−·), hydrogen peroxide (H2O2), and malondialdehyde (MDA) content were higher in the grass under severe drought relative to that under well-watered and mild drought stress at day 35. Mild drought stress increased catalase (CAT) and guaiacol peroxidase (POD) activity, induced new isoforms and increased band intensities of superoxide dismutase (SOD), CAT, and POD during cold acclimation (days 14 to 35). No differences in osmoprotectants, antioxidant metabolism, and freezing tolerance were found between mild drought and well-watered treatments. The results of this study suggest deficit irrigation-induced mild drought stress in late fall and winter could induce accumulation of osmoprotectants and improve antioxidant metabolism, and freezing tolerance, but severe drought stress could reduce freezing tolerance of creeping bentgrass in the region with limited precipitation.

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