scholarly journals Brassinosterioids Promote Photosynthetic Parameters of Pigeon Pea Plants under Water Deficit Conditions

2019 ◽  
Vol 8 (3S) ◽  
pp. 312-321
Keyword(s):  
Drought Stress ◽  
Chlorophyll Content ◽  
Water Deficit ◽  
Pigeon Pea ◽  
Photosynthetic Parameters ◽  
Stress Treatment ◽  
Chl A ◽  
Pea Seedlings ◽  
Control Application ◽  
The Impact

This study was aimed to find the effects of 28-epibrassinolide (28-EBL) and HBL on pigeon pea seedlings subjected to drought stress, either alone and supplemented with 28-EBL and HBL treatments. Supplementation of EBL alone also exhibited the significant improvement on chlorophyll content (44.3% of Chl a and 54.3 % of Chl b) than EBL under drought stress treatments compared to the control plants. Control plants receiving the EBL alone treatment showed the significant effect (by 36%) than the EBL under stress treatment (19.78%) compared to the control for carotenoid levels. supplementation of EBL exhibited the significant improvement of PN (36%; 0.0411, p≤0.05) over their individuals in comparison to control. application of EBL under unstressed was more effective (45%; 0.0341, p≤0.05) over stressed control than their individual applications in enhancing gS in control plants. Plants treated with HBL alone showed a marked increase in Ci (by 25.1%) compared to control plants. application of HBL and was also effective (41.2%; 0.0265, p≤0.05) over unstressed control than their individual applications in enhancing E in control plants. application of EBL and HBL considerably increased the Fv/Fm and ФPSII in comparison to unstressed control. Control plants treated with EBL exhibited the impact on RuBPcase activity (43.1%; 0.0411, p≤0.05) over stressed control than their individual applications over the control plants. application of EBL was more effective (66.7%; 0.0237, p≤0.05) over unstressed control than their individual applications in enhancing FBPase activity in control plants. Control plants treated with EBL and HBL was found to be less effective on the PGK activity by 66.2% (0.0112, p≤0.05) than their individuals (EBL by 163.9%) compared to control. EBL and HBL has a more significant effect than their individual applications on the improvement of leaf starch and sucrose concentrations in drought stressed and well-watered plants.

An increase in water deficit has no impact on the photosynthetic capacity of field-grown Mediterranean plants

2002 ◽  
Vol 29 (5) ◽  
pp. 621 ◽  
Author(s):  
Salvador Nogués ◽  
Leonor Alegre
Keyword(s):  
Water Deficit ◽  
Quantum Efficiency ◽  
Photosynthetic Capacity ◽  
Photosynthetic Parameters ◽  
Water Regimes ◽  
Relative Quantum ◽  
Mediterranean Plants ◽  
Psii Photochemistry ◽  
The Impact ◽  
Quantum Efficiency Of Psii

In the Mediterranean, annual mean precipitation has continuously decreased over the last three years (by ca 36% in Barcelona), and the decrease has been dramatic during the summer (by ca 78 and 64% during July and August, respectively). The impact of increased drought on the photosynthetic capacity of Mediterranean vegetation is currently unknown. In this study, two native Mediterranean plants [rosemary (Rosmarinus officinalis L.) and lavender (Lavandula stoechas L.)] were grown outdoors and subjected to two water regimes (50 mm month–1 during the summer, or no supplementary water at all). Rosemary and lavender plants watered with 50 mm month–1 during the summer had higher relative leaf water content and water potential than non-watered plants. Changes in water status were accompanied by large decreases in parameters of gas exchange [i.e. the light-saturated rate of CO2 assimilation, the maximum velocity of ribulose-1,5-bisphosphate (RuBP) carboxylation by Rubisco and the capacity for RuBP] and of modulated chlorophyll fluorescence (i.e. the relative quantum efficiency of PSII photochemistry and the efficiency of energy capture by open PSII reaction centres) during the summer, but no differences were found in any photosynthetic parameters for leaves subjected to the two water regimes. The drought-induced decreases in the relative quantum efficiency of PSII photochemistry in rosemary and lavender plants were attributable to ‘downregulation’ of electron transport. Photodamage to PSII in the field appeared to be a later effect of drought in these plants. Photorespiration was not a major mechanism protecting the photosynthetic apparatus of these plants from photodamage in the field. After the autumn rainfall, photosynthetic capacity fully recovered. We conclude that rosemary and lavender are well adapted to drought, and that an increase in water deficit is unlikely to have a significant impact on the photosynthetic capacity of leaves.

scholarly journals Brassinosterioids Stimulate Nitrogen Metabolism of Pigeon Pea Plants under Water Deficit Conditions

2019 ◽  
Vol 8 (3S) ◽  
pp. 300-307
Keyword(s):  
Drought Stress ◽  
Nitrogen Metabolism ◽  
Root Nodule ◽  
Dry Weight ◽  
Pigeon Pea ◽  
Stress Conditions ◽  
Fresh Weight ◽  
Enzymes Activities ◽  
Nodule Number ◽  
Pea Seedlings

This study was aimed to find the effects of 28-epibrassinolide (28-EBL) and HBL on pigeon pea seedlings subjected to drought stress, either alone and supplemented with 28-EBL and HBL treatments. Supplementation of EBL (2µM) and HBL (2µM) alone also exhibited the significant improvement in nodule number, nodule fresh weight, nodule dry weight, nodule Leghemoglobin content, root nodule nitrogenase (N2ase)under stress free conditions but under Drought stress conditions EBL (2µM) and HBL (2µM) exhibited the significant improvement in nodule number, nodule fresh weight ,nodule dry weight, nodule leghemoglobin content, root nodule nitrogenase (N2ase) while as control and other concentration (0.5,1 µM) didn’t performed up to level. Effect of Brassinosteroids increase the root nitrate reductase (NR), root nitrite reductase (NiR) activity, root nitrate (NO3-) content, root nitrite (NO2-) content, GS enzymes activities, under stress free conditions, under drought stress conditions this activity is ultimately low. Brassinosteroids at all concentration exhibited positive correlation with significantly raise in the root ammonium (NH4+) content and GOGAT enzymes activities. The present study shows that Pigeon pea plants under water stress, stimulate nitrogen metabolism effecting enzymes associated with it. But different concentration of 28-epibassinolide (0.5,1,2µM) and HBL were applied to the crop under drought stress- and stress-free conditions. Exogenous application of EBL and HBL promotes the Nitrogen Metabolism as plotted in the Graphs Further research is required for the detailed analysis.

scholarly journals FOLIAGE APPLIED SILICON AMELIORATES DROUGHT STRESS THROUGH PHYSIO-MORPHOLOGICAL TRAITS, OSMOPROTECTANTS AND ANTIOXIDANT METABOLISM OF CAMELINA (Camelina sativa L.) GENOTYPES

2021 ◽  
Vol 20 (4) ◽  
pp. 43-57
Author(s):  
Zahoor Ahmad ◽  
Ejaz Ahmad Warraich ◽  
Muhammad Aamir Iqbal ◽  
Celaleddin Barutçular ◽  
Hesham Alharby ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Chlorophyll Content ◽  
Foliar Application ◽  
Negative Impact ◽  
Turgor Pressure ◽  
Water Relation ◽  
Stress Conditions ◽  
Antioxidant Metabolism ◽  
The Impact

Silicon (Si) is one of the best plant defense elements against the biotic and abiotic stresses. Camelina plants accumulate Si which serves in protection against drought stress. The present study was conducted to investigate the impact of different doses of foliage applied Si (0, 3, 6 and 9 mM) under water stress (40% field capacity, FC) and non-stress conditions (100% FC) on camelina genotypes (Canadian and Australian). The imposed drought drastically decreased the growth parameters like root-shoot length and plant fresh and dry weight and also had negative impact on the chlorophyll content along with water relation attributes (water potential, osmotic potential and turgor pressure). In contrast, total free amino acids, total soluble proteins, proline and antioxidants such as ascorbic peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were enhanced especially in water stressed Canadian genotype, while osmoprotectants (flavonoids, anthocyanins and glycinebetaine) and phenolics contents were decreased. On the other hand, the foliar application of Si was instrumental in enhancing the growth of camelina by increasing the chlorophyll contents and water relation of stressed and non-stressed plants. Similarly, the biochemical, osmoprotectants and antioxidant metabolism was also improved in camelina stressed plants through the application of foliar Si. In conclusion, foliar application of 6 mM Si at vegetative growth stage played a vital role in alleviating the drastic impact of water stress on camelina growth by improving the water status, chlorophyll content, accumulation of phenolics and osmoprotectants and activating antioxidants. Therefore, the foliar application of Si could be developed as an important biologically viable strategy for boosting the tolerance in camelina plants to water stress conditions.

The Effects of Drought Stress on the Photosynthetic Parameters and Dry Leaf Yield of Stevia rebaudina Bertoni

2012 ◽  
Vol 518-523 ◽  
pp. 4786-4789 ◽  
Author(s):  
Guang Xi Ren ◽  
Yan Shi
Keyword(s):  
Drought Stress ◽  
Transpiration Rate ◽  
Photosynthetic Parameters ◽  
Short Term ◽  
Leaf Production ◽  
Stress Treatment ◽  
Leaf Yield ◽  
Maximum Decrease ◽  
Effects Of Drought ◽  
Mild Drought

The effects of drought stress on the photosynthesis and dry leaf yield in the different Stevia rebaudina Bertoni germplasms of: IS-1, QF-1, QTZ4, JD-1 and AL-4 was studied with the pot method in greenhouse. The results indicated that the net photosynthetic (Pn), transpiration rate (Tr) and dry leaf production of stevia showed different degree changes with the continuing of drought-stress time. There was no significant change in Pn, Tr and dry leaf production in short-term drought-stress treatment(Ta:5d), but as the time of drought-stress continuing, the Pn were on the declining trend: the Pn of various materials in T2 (without irrigation for 10d) showed maximum decrease, they decreased for 28.85%, 47.04%, 43.03%, 43.61% and 42.25% than that in T1 (without irrigation for 5d), respectively. The variation trend of Tr in various materials were the same to the Pn. And it indicated that there was no appreciable impact on the dry leaf yield in the mild drought (without water for 5d), but with the drought stress continuing, the dry leaf yield of per plant became less and less. The varying degrees decreases of dry leaf yield in different materials with the same drought stress showed that different materials with different tolerance to drought stress.

scholarly journals Silver nanoparticles improve growth and protect against oxidative damage in eggplant seedlings under drought stress  

2021 ◽  
Author(s):  
Nadiyah M. Alabdallah ◽  
Md. Mahadi Hasan ◽  
Abdalrhaman M. Salih ◽  
S.S. Roushdy ◽  
Aisha S. Al-Shammari ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Crop Production ◽  
Negative Impact ◽  
Growth Parameters ◽  
Low Cost ◽  
Dry Mass ◽  
Chl A ◽  
Mda Content ◽  
The Impact

Drought stress is a significant abiotic stressor that has a negative impact on crop production and global food security systems. Drought stress was applied to eggplant seedlings with various field capacities (FC), 80% FC as control, 50% FC, 35% FC, and 20% FC. AgNPs were synthesised from green chemical methods, whereas different concentrations of AgNPs (0, 0.1, 0.2, 0.5 µmol) were applied exogenously on drought-stressed eggplants. Drought stress decreased the growth parameters (plant height, fresh mass, dry mass, leaf area), photosynthetic pigments (Chl a, Chl b, carotenoids), and protein content while increased the proline, hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), malondialdehyde (MDA) content, and activity of the antioxidant enzymes, i.e., superoxide dismutase (SOD) and catalase (CAT). AgNPs restricted proline accumulation and reduced H<sub>2</sub>O<sub>2,</sub> MDA content by upregulating the antioxidant enzymes. Overall, the current study’s findings indicated that AgNPs are an effective eco-friendly and low-cost application for plant growth under drought stress, with the potential to mitigate the impact of drought on plants.

scholarly journals The effect of mycorrhiza and vermicompost bio-fertilizers on some physiological characteristics of sweet basil plant (Ocimum basilicum L.) under the stress condition caused by water deficit

2017 ◽  
Vol 7 (4) ◽  
pp. 325-329
Author(s):  
Masoud Rafiee ◽  
Azin Ghavami ◽  
Vahid Abdossi ◽  
Ahmad Khalighi
Keyword(s):  
Drought Stress ◽  
Water Deficit ◽  
Crop Production ◽  
Dry Weight ◽  
Ocimum Basilicum ◽  
Limiting Factors ◽  
Water Deficit Stress ◽  
Stress Treatment ◽  
Sweet Basil ◽  
Shoot Dry Weight

<p>One of the main limiting factors in crop production in different regions of Iran is water deficit stress. Mycorrhiza and vermicompost fertilizer may be help plants to uptake more water. Therefore, a greenhouse experiment was carried out in factorial design that was carried out to evaluate the effect of Mycorrhiza, vermicompost fertilizer and water deficit stress on some physiological traits of sweet basil (<em>Ocimum basilicum</em> L.). Factors included Mycorrhiza (inoculation and non-inoculation), Vermicompost fertilizer (0, 30, 50, and 70 percentage of pod volume), and water deficit stress factor included irrigating up to 60% of F.C as water deficit stress treatment, up to 75% of F.C as mild water deficit stress treatment and up to 90% of F.C as well irrigated treatment. The results showed that sugars and proline increased with increasing water deficit stress, while higher vermicompost consumption decreased the severity of the increase. Merging vermicompost, and mycorrhiza, had a synergistic effect on the catalase enzyme and chlorophyl a+b. Significant negative and positive relationships were found between shoot dry weight and proline with water deficit stress. In addition, basil plant physiological responses to drought stress showed that this stress-sensitive plants, tried to adjust to stress, through osmotic adjustment and increasing antioxidant activity. The results totally showed that merging mycorrhizal inoculation and vermicompost mitigate the effects of drought stress in Basil. </p>

scholarly journals Modulation of Physiological and Biochemical Traits of Two Genotypes of Rosa Damascena Mill. By Nano Silicon Under in Vitro Drought Stress

2021 ◽  
Author(s):  
Hanifeh Seyed Hajizadeh ◽  
Sahar Azizi ◽  
Farzad Rasouli ◽  
Volkan Okatan
Keyword(s):  
Drought Stress ◽  
Protein Content ◽  
Water Deficit ◽  
Membrane Stability ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase ◽  
Photosynthetic Parameters ◽  
Rosa Damascena ◽  
Severe Drought ◽  
Nano Silicon

Abstract Drought is a major abiotic stress that prevents plant growth and efficiency. Silicon increases drought tolerance by regulating the biosynthesis and acumulation of some osmolits.This study was conducted to modulate dought stress induced by Polyethylene glycol (PEG) in two genotypes of damasks by nano silicon dioxide (nSiO2). The experiment included three levels of nSiO2 (0, 50 and 100 mg L-1) and PEG (0, 25, 50, 75 and 100 g L-1) added to culture medium. Drought stress decreased protein content while Maragheh genotype under normal conditios and treating with 100 mg L-1 nSiO2 had the highest protein content. Under severe drought stress Maragheh genotype had stronger membrane stability index (MSI) than Kashan genotype and explants treated with 100 mg L-1 nSiO2 had the highest MSI in control plants. Contrary to the negative effects of drought, plants treated with 100 mg L−1 nSiO2 maintained more of their photosynthetic parameters in comparison with other treatments and showed higher amount of protein and proline in Maragheh rather than kashan genotype. Drought stress reduced the values of Fm, Fv/Fm, and Fv. In general, under drought stress, treatment with nSiO2 increased the mentioned characteristics before. It also improved water deficit tolerance through enhancing in the activity of antioxidant enzymes such as catalase, peroxidase, guaiacol peroxidase and superoxide dismutase while the amount of lipid peroxidation and hydrogen peroxide decreased. The results showed that Maragheh genotype may be more stronger in counter with water deficit by improving in water balance, antioxidant enzyme activities, and membrane stability.

scholarly journals Shade stress on maize seedlings biomass production and photosynthetic traits

2022 ◽  
Vol 52 (3) ◽  
Author(s):  
Liuzheng Yuan ◽  
Jiayou Liu ◽  
Zhiyong Cai ◽  
Huiqiang Wang ◽  
Jiafeng Fu ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Shoot Biomass ◽  
Photosynthetic Parameters ◽  
Natural Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Stress Treatment ◽  
Mda Content ◽  
The Impact

ABSTRACT: The responses of two maize (Zea mays L.) cultivars, ‘LY336’ (shade tolerant) and ‘LC803’ (shade sensitive), to shade stress in a pot experiment conducted in the 2015 and 2016 growing seasons were investigated. The impact of 50% shade stress treatment on shoot biomass, photosynthetic parameters, chlorophyll fluorescence, and malondialdehyde (MDA) content was evaluated. The shoot biomass of the two maize hybrids was decreased significantly by shade stress treatment, for shade stress 7 d, the LC803 and LY336 were reduced by 56.7% and 44.4% compared with natural light. Chlorophyll fluorescence parameters of LY336 were not significantly affected by shade stress, whereas those of LC803 were significantly affected, the Fo increased under shade stress; however Fm, FV/FM and ΦPSII were decreased under shade stress. Among photosynthetic parameters measured, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate were significantly decreased compared with natural light, LY336 and LC803 reduction by 28.0%, 22.2%, 57.7% and 35.5%, 18.9%, 62.4%; however, intercellular CO2 concentration (Ci) was significantly increased, for the two cultivars. Under shade stress for different durations (1, 3, 5, 7 d), Pn, Gs, Ci, and MDA content differed significantly between the two cultivars. Results indicated that different maize genotypes showed different responses to shading. Shade-tolerant genotypes are only weakly affected by shade stress.

The Impact of Drought Stress on some Morpho-Physiological Traits and RAPD Markers in Wheat Genotypes

2015 ◽  
Vol 4 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Bayoumi Y. ◽  
Amal Abd EL-Mageed ◽  
Enas Ibrahim ◽  
Soad Mahmoud ◽  
I. El-Demardash ◽  
...  
Keyword(s):  
Drought Stress ◽  
Rapd Markers ◽  
Physiological Traits ◽  
Wheat Genotypes ◽  
The Impact
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