Exploration of physiological and biochemical processes of canola with exogenously applied fertilizers and plant growth regulators under drought stress

Environmental stresses may alter the nutritional profile and economic value of crops. Chemical fertilizers and phytohormones are major sources which can enhance the canola production under stressful conditions. Physio-biochemical responses of canola altered remarkably with the use of nitrogen/phosphorus/potassium (N/P/K) fertilizers and plant growth regulators (PGRs) under drought stress. The major aim of current study was to evaluate nutritional quality and physio-biochemical modulation in canola (Brassica napus L.) from early growth to seed stage with NPK and PGRs in different water regimes. To monitor biochemical and physiological processes in canola, two season field experiment was conducted as spilt plot under randomized complete block design (RCBD) with four treatments (Control, Chemical fertilizers [N (90 kg/ha), P and K (45 kg ha-1)], PGRs; indole acetic acid (IAA) 15g ha-1, gibberellic acid (GA3) 15g ha-1 and the combination of NPK and PGRs] under different irrigations regimes (60, 100, 120, 150 mm evaporations). Water stress enhanced peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), polyphenol oxidase (PPO), soluble sugar, malondialdehyde (MDA), proline contents as well as leaf temperature while substantially reduced leaf water contents (21%), stomatal conductance (50%), chlorophyll contents (10–67%), membrane stability index (24%) and grain yield (30%) of canola. However, the combined application of NPK and PGR further increased the enzymatic antioxidant pool, soluble sugars, along with recovery of leaf water contents, chlorophyll contents, stomatal conductance and membrane stability index but decreased the proline contents and leaf temperature at different rate of evaporation. There is positive interaction of applied elicitors to the water stress in canola except leaf area. The outcomes depicted that the combination of NPK with PGRs improved the various morpho-physiological as well as biochemical parameters and reduced the pressure of chemical fertilizers cost about 60%. It had also reduced the deleterious effect of water limitation on the physiology and grain yield and oil contents of canola in field experiments.

Download Full-text

Effects of Climate Temperature and Water Stress on Plant Growth and Accumulation of Antioxidant Compounds in Sweet Basil (Ocimum basilicum L.) Leafy Vegetable

Scientifica ◽

10.1155/2020/3808909 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Asma Al-Huqail ◽

Rehab M. El-Dakak ◽

Marwa Nme Sanad ◽

Reem H. Badr ◽

Mohamed M. Ibrahim ◽

...

Keyword(s):

Water Stress ◽

Plant Growth ◽

Growth Parameters ◽

Stress Conditions ◽

Total Phenolic ◽

Antioxidant Compounds ◽

Chlorophyll Contents ◽

Sweet Basil ◽

Stress Markers ◽

Response To Water

The effects of climate temperature and water stress on growth and several stress markers were investigated in sweet basil plants. Some growth parameters (shoot length and number of leaves) and photosynthetic chlorophyll contents were determined every two days during plant growth, and foliage leaf material was collected after 15 and 21 days of treatment. Both climate temperature and water stress inhibited sweet basil plant growth; especially, total chlorophyll levels were decreased significantly in response to high-temperature treatments. Under strong stresses, basil plants induced the synthesis and accumulation of glycine betaine (GB) as a secondary osmolyte, although at less content when compared with the proline content under the same stress conditions. Proline concentrations particularly increased in leaves of both basil stressed plants, accomplishing levels high enough to play a crucial role in cellular osmoregulation adjustment. Stress-induced accumulation of these antioxidant compounds was detected in sweet basil. Therefore, it appears that sweet basil-treated plants are able to synthesize antioxidant compounds under strong stress conditions. On the other hand, total sugar concentrations decreased in stress-treated basil plants. Both temperature and water stress treatments caused oxidative stress in the treated plants, as indicated by a significant increment in malondialdehyde (MDA) concentrations. An increase in total phenolic and flavonoid concentrations in response to water stress and a highly significant decrease in carotenoid concentrations in basil leaves were observed; flavonoids also increased under high climate temperature conditions.

Download Full-text

Effects of Salt and Water Stress on Plant Growth and on Accumulation of Osmolytes and Antioxidant Compounds in Cherry Tomato

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4319793 ◽

2015 ◽

Vol 43 (1) ◽

pp. 1-11 ◽

Cited By ~ 28

Author(s):

Mohamad AL HASSAN ◽

Marina MARTÍNEZ FUERTES ◽

Francisco José RAMOS SÁNCHEZ ◽

Oscar VICENTE ◽

Monica BOSCAIU

Keyword(s):

Water Stress ◽

Plant Growth ◽

Glycine Betaine ◽

Growth Parameters ◽

Stem Length ◽

Antioxidant Compounds ◽

Cherry Tomato ◽

Chlorophyll Contents ◽

Stress Markers ◽

Number Of Leaves

The effects of salt and water stress on growth and several stress markers were investigated in cherry tomato plants. Some growth parameters (stem length and number of leaves) and chlorophyll contents were determined every third day during plant growth, and leaf material was collected after 25 and 33 days of treatment. Both stresses inhibited plant growth; chlorophyll levels, however, decreased only in response to high NaCl concentrations. Proline contents largely increased in leaves of stressed plants, reaching levels high enough to play a major role in cellular osmotic adjustment. Despite reports indicating that tomato does not synthesize glycine betaine, the stress-induced accumulation of this osmolyte was detected in cherry tomato, albeit at lower concentration than that of proline. Therefore, it appears that the plants are able to synthesise glycine betaine as a secondary osmolyte under strong stress conditions. Total sugars levels, on the contrary, decreased in stress-treated plants. Both stress treatments caused secondary oxidative stress in the plants, as indicated by a significant increase in malondialdehyde (MDA) contents. Water stress led to an increase in total phenolics and flavonoid contents and a reduction of carotenoid levels in the leaves; flavonoids also increased under high salinity conditions.

Download Full-text

Water Stress Limits Growth and Physiological Performance of Jatropha curcas L. Seedlings

Journal of Agriculture and Ecology Research International ◽

10.9734/jaeri/2020/v21i1030174 ◽

2020 ◽

pp. 47-53

Author(s):

Bassirou Sine ◽

Bassiaka Ouattara ◽

Diariétou Sambakhé ◽

Alassane Waly Ngom ◽

Aïda Ndiaye

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Plant Height ◽

Jatropha Curcas ◽

Climatic Conditions ◽

Leaf Temperature ◽

Arid Zones ◽

Jatropha Curcas L ◽

Collar Diameter ◽

Semi Arid

Jatropha (Jatropha curcas L.) is a potential biodiesel plant that gained much attention in non-oil production countries. We investigated the ability of the species to cope with water deficit occurring in semi-arid zones like Senegal climatic conditions. The layout of the experiment was a randomized complete blocks design with two factors (level and frequency of irrigation) and 6 repetitions. The trial was conducted from December 2012 to June 2013 in CERAAS/ISRA at Thiès, Senegal. Potted Jatropha seedlings were exposed, after three months under similar well-watered conditions, to three water regimes (100%, 50% and 25% of ﬁeld capacity, respectively C100, C50 and C25) and two frequency of watering once and twice watering a week(F1 and F2, respectively). The different treatments didn’t affect significantly collar diameter and plant height during the time of the experimentation. Nevertheless, the trend line is up for collar diameter and plant height in well-watered plants. For the same frequency of irrigation, biomass accumulated was high in C100. No difference was found between plants biomass in C25-F1 and C25-F2. For physiological parameters, there are no differences between the treatments at the onset of stress. However, after 2 weeks of stress, photosynthesis, stomatal conductance and transpiration were affected permanently in treatments C100-F1, C50-F1 and C25-F1 and their values never reached those of plants of C100-F2, 50-F2 and C25-F2. The opposite was noted for leaf temperature. For the same frequency of irrigation, photosynthesis, stomatal conductance and transpiration were higher in C100 and the opposite occurred for the leaf temperature. These results demonstrate that growth and productivity of Jatropha are significantly affected by water stress conditions. Its need to be watered regularly to maintain physiological functions and biomass production definitely highlights that its growth in semi-arid zones is economically unlikely.

Download Full-text

MUTATION BREEDING OF A RICE DWARF LINE WITH SLIGHT YIELD LOSS UNDER DROUGHT STRESS

Plant Breeding and Seed Science ◽

10.37317/pbss-2018-0005 ◽

2018 ◽

Vol 77 ◽

pp. 55-67

Author(s):

Asadollah Ahmadikhah ◽

Amir Marufinia ◽

Esmaeil Sharifzadeh

Keyword(s):

Water Stress ◽

Drought Stress ◽

Yield Loss ◽

Mutation Breeding ◽

Mutant Line ◽

Line Field ◽

Plant Yield ◽

Chlorophyll Contents ◽

Mutant Lines ◽

Parental Cultivar

Lack of adequate water leading to drought stress is a common constraint in upland cultivation system ofrice. a rice mutant line (MT58) was developed in previous research after mutagenesis of cv. Neda by ethylmethane sulfonate (EMS) and selected for dwarfism (18 cm shorter than Neda). The extent of its molecularchanges relative to parental cultivar was assessed by SSR and ISSR markers, and the response of the linealong with parental cultivar and another mutant line (MTA) to mild and severe water deficit, was evaluated ina field experiment. a molecular assessment by using 41 SSR markers showed that stunt line MT58 had significantmolecular difference with two other lines as confirmed by cluster analysis. ISSR assay also proved theconsiderable mutational effect of EMS on two mutant lines compared to original wild line. Field experimentsrevealed that limited irrigation caused mild to severe decrease in all the studied traits including chlorophyllcontents. In both mild and sever water stress (S1 and S2) dwarf mutant MT58 had not significant differencesin plant yield from parental cultivar Neda. In mild water stress cultivar Neda and mutant line MT58, respectively,showed highest (14%) and lowest (3%) yield loss, while in sever water stress mutant lines MTA andMT58, respectively, showed highest (33%) and lowest (19%) yield loss. In severe stress, cultivar Neda hadhighest plant height, tiller number and plant yield, and mutant MT58 had highest panicle length, total kernelsper panicle, fertile kernels and chlorophyll contents. Reduction in chlorophyll content at drought stress conditionwas correlated with yield loss (0.64 and 0.697 for chl.a and chl.b, respectively). The results of this researchobviously confirm that mutant line MT58 despite of its stunt figure did not show yield difference fromits parental cultivar in drought stress.

Download Full-text

Screening of marigold (Tagetes erecta L.) cultivars for drought stress based on vegetative and physiological characteristics

International Journal of Food and Allied Sciences ◽

10.21620/ijfaas.2017256-63 ◽

2018 ◽

Vol 3 (2) ◽

pp. 56 ◽

Cited By ~ 1

Author(s):

Adnan Younis ◽

Atif Riaz ◽

Muhammad Qasim ◽

Farakh Mansoor ◽

Faisal Zulfiqar ◽

...

Keyword(s):

Water Stress ◽

Drought Stress ◽

Tagetes Erecta ◽

Drought Treatment ◽

Chlorophyll Contents ◽

Drought Tolerant ◽

Randomized Design ◽

Cultivar Selection ◽

Tagetes Erecta L ◽

Water Scarce

Drought tolerance is an important genotypic character to be exploited for the plant cultivar selection under water deficit conditions. In the recent study, we examined the response of two marigold cultivars (Inca and Bonanza) under different regimes of drought stress. The aim was to determine the best performing cultivar under water/drought stress. Three irrigation treatments include; 4 days (T1), 6 days (T2) and 8 days (T3) in comparison to control 1 day (T0) interval were imposed. Response characters under study were morphological, physiological and anatomical. Complete Randomized Design (CRD) with four replications in two factorial arrangements was followed for experiment layout. The results revealed that increasing water stress adversely affect plant height, in both cultivars. Both cultivars showed a decreasing trend to the number of flowers under water stress. Total chlorophyll contents including a, b were also showed reduction under prolonged drought treatment in both cultivars from (2.7 mg g-1 FW) to (1 mg g-1 FW). Overall, the performance of cultivar (cv.) Inca was satisfactory under water stress regimes. These results are helpful for selecting drought tolerant marigold cultivars in water scarce areas.

Download Full-text

Priming improves germination and seed reserve utilization, growth, antioxidant responses and membrane stability at early seedling stage of Saudi sorghum varieties under drought stress

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha48211841 ◽

2020 ◽

Vol 48 (2) ◽

pp. 938-953

Author(s):

Taieb TOUNEKTI ◽

Mosbah MAHDHI ◽

Zarraq AL-FAIFI ◽

Habib KHEMIRA

Keyword(s):

Water Stress ◽

Drought Stress ◽

Seed Germination ◽

Seedling Growth ◽

Seedling Emergence ◽

Stability Index ◽

Stress Conditions ◽

Water Stress Condition ◽

Significant Difference ◽

Early Seedling

Seeds of three sorghum (Sorghum bicolor (L.) Moench.) varieties from Southwest Saudi Arabia were used to investigate the potential of osmopriming with polyethylene glycol (PEG 8000) to improve germination performance, seed reserve utilization and early seedling growth and drought stress tolerance. The primed (PS) and unprimed (UPS) seeds of the three sorghum varieties were germinated for 8 days under increasing PEG-induced osmotic stress. The treatments were arranged in a completely randomized design, in a factorial arrangement, with three sorghum cultivars (‘Zaydia’, ‘Shahbi’ and ‘Ahmar’) and four osmotic potentials (0.0; -0.4; -0.8 and -1.2 MPa) with four replicates of 50 seeds each. The results showed that drought stress affected seed germination and seedling emergence and establishment, but increased the activity of the antioxidant enzyme catalase (CAT). The strongest inhibition of germination and growth occurred at the highest PEG concentration and a significant difference was noticeable between the studied varieties. We confirmed also that seed osmopriming improved seed germination performance, seedling growth and enhanced the CAT activities while reduced malonyldialdehyde (MDA) accumulation and electrolyte leakage (EL) in the drought-stressed seedlings. Seed priming have enhanced also the α-amylase and total proteases activities in all varieties. The largest increase of these hydrolysing enzymes was shown in ‘Ahmar’. Furthermore, the PEG priming lead to improvement of the weight of utilized (mobilized) seed reserve (WUSR), seed reserve depletion percentage (SRDP) and total seedling dry weight (SLDW) of sorghum seedlings under water stress conditions. Still, the highest values or all three parameters were found in the ‘Ahmar’ variety. Under increasing drought stress conditions, ‘Ahmar’ showed the highest yield stability index (YSI) and the least EL and MDA contents in comparison to the other two varieties during the seedling establishment stage. Therefore, the former variety can tolerate better a rigorous water stress condition. ‘Zaydia’ appears to be the most vulnerable to drought stress. Thus, the use of species or varieties with eminent seed metabolic quality is an advantageous trait in drought-prone regions.

Download Full-text

Deciphering the Mechanisms of Microbe Mediated Drought Stress Alleviation in Wheat

10.21203/rs.3.rs-1100465/v1 ◽

2021 ◽

Author(s):

DEVENDRA SINGH ◽

Shobit Thapa ◽

Jagriti Yadav ◽

Dikchha SINGH ◽

Hillol Chakdar ◽

...

Keyword(s):

Water Stress ◽

Drought Stress ◽

Plant Growth ◽

Sugar Content ◽

Pcr Analysis ◽

Stress Alleviation ◽

Microbial Inoculation ◽

Water Stress Condition ◽

Plant Growth Promoting ◽

Plant Growth Promoting Microbes

Abstract Drought stress adversely influences the crop plants. Herein, present research was designed to elucidate the role of plant growth promoting microbes for amelioration of water stress in wheat. A pot experiment was conducted for screening the microorganisms on the basis of plant growth, chlorophyll and proline content under water stress. Bacillus sp. BT3 and Klebsiella sp. HA9 were found more promising strains that positively influenced the plant growth, chlorophyll and proline status of seedlings under water stress condition. Further, Bacillus sp. BT-3 and Klebsiella sp. HA9 along with check strain (BioNPK) were used for elucidating their detailed effect on morphological, biochemical, physiological and molecular traits to mitigate drought stress in wheat. Microbial inoculation significantly enhanced plant growth, biomass, relative water content, chlorophyll content and root morphological parameters over the uninoculated water stressed (30% FC) control. Likewise, sugar content, protein content and antioxidant enzymes were also significantly enhanced due to microbial inoculation under water stress (30% FC). Microbial inoculation significantly decreased proline, glycine betaine, lipid peroxidation, peroxide and superoxide radicals in wheat over the uninoculated water stressed (30%FC) control. Quantitative real-time (qRT)- PCR analysis revealed that Bacillus sp. BT-3, Klebsiella sp. HA9 and BioNPK inoculation significantly upregulated stress responsive genes (DHN, DREB, L15 and TaABA-8OH) over the uninoculated water stressed (30% F.C.) control. The study reports the potential of Bacillus sp. BT3 and Klebsiella sp. HA9 along with BioNPK in water stress alleviation in wheat which could be recommended as effective biofertilizers.

Download Full-text

The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions

Canadian Journal of Microbiology ◽

10.1139/w08-144 ◽

2009 ◽

Vol 55 (4) ◽

pp. 388-394 ◽

Cited By ~ 37

Author(s):

Scott M. Liddycoat ◽

Bruce M. Greenberg ◽

David J. Wolyn

Keyword(s):

Water Stress ◽

Drought Stress ◽

Plant Growth ◽

Plant Growth Promoting Rhizobacteria ◽

Asparagus Officinalis ◽

Positive Effects ◽

Transplant Shock ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Germinating Seeds

Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus ( Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR ( Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of ‘Guelph Millennium’ under optimum conditions and ‘Jersey Giant’ seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for ‘Guelph Millennium’, for which both single or multiple inoculations enhanced plant growth under drought stress.

Download Full-text

Interactive Impacts of Beneficial Microbes and Si-Zn Nanocomposite on Growth and Productivity of Soybean Subjected to Water Deficit under Salt-Affected Soil Conditions

Plants ◽

10.3390/plants10071396 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1396

Author(s):

Hany S. Osman ◽

Salah M. Gowayed ◽

Mohssen Elbagory ◽

Alaa El-Dein Omara ◽

Ahmed M. Abd El-Monem ◽

...

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Plant Growth ◽

Photosynthetic Pigments ◽

Soil Salinity ◽

Root Length ◽

Seed Quality ◽

Dry Weight ◽

Soil Conditions ◽

Salt Affected Soil

Water stress or soil salinity is considered the major environmental factor affecting plant growth. When both challenges are present, the soil becomes infertile, limiting plant productivity. In this work a field experiment was conducted during the summer 2019 and 2020 seasons to evaluate whether plant growth-promoting microbes (PGPMs) and nanoparticles (Si-ZnNPs) have the potential to maintain soybean growth, productivity, and seed quality under different watering intervals (every 11 (IW0), 15 (IW1) and 19 (IW2) days) in salt-affected soil. The most extended watering intervals (IW1 and IW2) caused significant increases in Na+ content, and oxidative damage indicators (malondialdehyde (MDA) and electrolyte leakage (EL%)), which led to significant reductions in soybean relative water content (RWC), stomatal conductance, leaf K+, photosynthetic pigments, soluble protein. Subsequently reduced the vegetative growth (root length, nodules dry weight, and total leaves area) and seeds yield. However, there was an enhancement in the antioxidants defense system (enzymatic and non-enzymatic antioxidant). The individual application of PGPMs or Si-ZnNPs significantly improved leaf K+ content, photosynthetic pigments, RWC, stomatal conductance, total soluble sugars (TSS), CAT, POD, SOD, number of pods plant−1, and seed yield through decreasing the leaf Na+ content, MDA, and EL%. The combined application of PGPMs and Si-ZnNPs minimized the adverse impact of water stress and soil salinity by maximizing the root length, heavier nodules dry weight, leaves area, TSS and the activity of antioxidant enzymes, which resulted in higher soybean growth and productivity, which suggests their use under harsh growing conditions.

Download Full-text

Photosynthesis and Stomatal-Conductance Responses of Johnsongrass (Sorghum halepense) to Water Stress

Weed Science ◽

10.1017/s0043174500082990 ◽

1985 ◽

Vol 33 (5) ◽

pp. 635-639 ◽

Cited By ~ 11

Author(s):

Bryan L. Stuart ◽

Daniel R. Krieg ◽

John R. Abernathy

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Potential ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Osmotic Potential ◽

Grain Filling ◽

Leaf Temperature ◽

Sorghum Halepense

The influence of water stress on johnsongrass [Sorghum halepense(L.) Pers. ♯ SORHA] physiology was evaluated in a semiarid environment. Stomatal conductance of johnsongrass responded to more negative leaf water potential and increasing leaf temperature. The sensitivity of the leaf temperature effect was dependent on the soil water content. At low soil water content, conductance was limited by low water potential, and increasing leaf temperature had little effect. Conductance of CO2was related to net photosynthesis in a curvilinear manner, with conductance levels greater than 0.3 mol·m-2· s-1being in excess of that necessary for maximum photosynthesis. At both high conductance levels and low levels associated with increased water stress, intercellular CO2concentration increased, indicating nonstomatal limitations to photosynthesis. Decreased osmotic potential provided the highest correlation with the linear decline of photosynthetic rate as stress intensified. The expression of osmotic adjustment in johnsongrass is reported during grain filling. Plants in the milkdough stage of grain filling had approximately 0.3 MPa lower osmotic potential at any relative water content than those at anthesis.

Download Full-text