Implications of ectomycorrhizal inoculation for drought stress tolerance of Atlas cedar (Cedrus atlantica (Endl.) Carrière) seedlings

Background: Ectomycorrhizal inoculation is a promising strategy to minimise the initial transplant shock and increase plant survival and growth during the first years of out-planting in the field. The aim of this research was to investigate the effect of sporal inoculum of three ectomycorrhizal fungi: Cortinarius cedretorum, Amanita vaginata and Inocybe geophylla on tolerance levels of Atlas cedar (Cedrus atlantica (Endl.) Carrière) seedlings subjected to applied drought stress in nursery conditions. Methods: Carpophores, seeds and organic forest soil were collected under pure stands of Atlas cedar. After fifteen months of growth, seedlings were subjected to drought stress by withholding water for thirty days; we assessed morphological and physiological variables of all seedling batches (inoculated and uninoculated, controlled and stressed seedlings) Results: All roots of inoculated stressed seedlings were mycorrhizal. The mycorrhization rates were 67%, 64.6% and 53.6% for stressed seedlings inoculated with Cortinarius cedretorum, Amanita vaginata, Inocybe geophylla, respectively. This root mycorrhization was accompanied by a significant improvement in seedling growth, especially height and length of the main root (10.2 cm, 52 cm) reached in stressed seedlings inoculated with Cortinarius cedretorum. There was a significant increase in relative water content, total chlorophyll, carotenoids, soluble sugars and starch, superoxide dismutase and ascorbate peroxydase enzyme activities in inoculated stressed seedlings compared with uninoculated seedlings. Conclusions: Inoculation of Atlas cedar seedlings with spores of ectomycorrhizal fungi remains a very effective alternative for improving growth and the morphological and physiological status of seedlings under drought conditions. Cortinarius cedretorum appears to be consistently advantageous followed by Amanita vaginata and Inocybe geophylla.

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Molecular and Physio-Biochemical Characterization of Cotton Species for Assessing Drought Stress Tolerance

International Journal of Molecular Sciences ◽

10.3390/ijms19092636 ◽

2018 ◽

Vol 19 (9) ◽

pp. 2636 ◽

Cited By ~ 10

Author(s):

Md Hasan ◽

Fanglu Ma ◽

Zakaria Prodhan ◽

Feng Li ◽

Hao Shen ◽

...

Keyword(s):

Drought Stress ◽

Biochemical Characterization ◽

Soluble Sugars ◽

Photochemical Efficiency ◽

Development Program ◽

Photochemical Efficiency Of Psii ◽

Relative Expression Level ◽

Cotton Species ◽

Relative Water

Drought stress significantly limits cotton growth and production due to the necessity of water at every stage of crop growth. Hence, it is essential to identify tolerant genetic resources and understand the mechanisms of drought tolerance in economically and socially important plants such as cotton. In this study, molecular and physio-biochemical investigations were conducted by analyzing different parameters by following standard protocols in three different cotton species, namely TM-1 (Gossypium hirsutum), Zhongmian-16 (Gossypium arboreum), and Pima4-S (Gossypium barbadense). Drought stress significantly decreased plant growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), maximum photochemical efficiency of PSII (Fv/Fm), and relative water content. TM-1 resulted in more tolerance than the other two species. The accumulation of proline, soluble proteins, soluble sugars, hydrogen peroxide (H2O2), and superoxide radicals (O2•−) increased significantly in TM-1. In addition, TM-1 maintained the integrity of the chloroplast structure under drought conditions. The relative expression level of drought-responsive genes including coding for transcription factors and other regulatory proteins or enzymes controlling genes (ERF, ERFB, DREB, WRKY6, ZFP1, FeSOD, CuZnSOD, MAPKKK17, P5CR, and PRP5) were higher in TM-1 under drought, conferring a more tolerant status than in Zhongmian-16 and Pima4-S. The findings of this research could be utilized for predicting a tolerant cotton genotype as well as evaluating prospective cotton species in the variety development program.

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Osmoregulants Involved in Osmotic Adjustment for Differential Drought Tolerance in Different Bentgrass Genotypes

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.140.6.605 ◽

2015 ◽

Vol 140 (6) ◽

pp. 605-613 ◽

Cited By ~ 6

Author(s):

Nanqing Liu ◽

Yixin Shen ◽

Bingru Huang

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Osmotic Adjustment ◽

Soluble Sugars ◽

Creeping Bentgrass ◽

Genetic Variations ◽

Agrostis Stolonifera ◽

Turf Quality ◽

Relative Water ◽

Highly Correlated

Compatible solute accumulation regulating osmotic adjustment (OA) is associated with drought tolerance. The objectives of this study were to examine genetic variations in OA among a diverse group of bentgrass (Agrostis sp.) genotypes or lines with differential drought tolerance, and determine major types of organic osmoregulants contributing to OA and accounting for the genetic variations in drought tolerance. A wild type cultivar of creeping bentgrass [Agrostis stolonifera (Penncross)], a transgenic line of creeping bentgrass (SAGIPT41), and four hybrid bentgrass lines [Agrostis capillaris × Agrostis stolonifera (ColxCr14, ColxCr190, ColxCr481, and ColxCr679)] were exposed to drought stress by withholding irrigation for 17 days in growth chambers. Among genotypes, ColxCr14, ColxCr190, and SAGIPT41 showed superior drought tolerance, as manifested by higher turf quality (TQ) and leaf relative water content (RWC), as well as OA than ‘Penncross’, ColxCr679, and ColxCr481 under drought stress. SAGIPT41 leaves accumulated greater content of soluble sugars (glucose, sucrose, and fructose), proline, glycine betaine (GB), and spermine; ColxCr190 had higher content of soluble sugars and spermidine; and ColxCr14 accumulated more soluble sugars and GB, compared with the three drought-sensitive genotypes. Soluble sugars were predominant contributors to OA, followed by GB and proline, with all three forms of polyamine (PA) as minor contributors in bentgrass genotypes. The osmolytes highly correlated to OA and superior drought tolerance could be used as biomarkers to select for drought-tolerant germplasm of bentgrass and other cool-season turfgrass species.

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Drought Stress Alleviation by Potassium-Nitrate-Containing Chitosan/Montmorillonite Microparticles Confers Changes in Spinacia oleracea L.

Sustainability ◽

10.3390/su13179903 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9903

Author(s):

Syed Abubkar Haider ◽

Irfana Lalarukh ◽

Syeda Fasiha Amjad ◽

Nida Mansoora ◽

Maliha Naz ◽

...

Keyword(s):

Drought Stress ◽

Spinacia Oleracea ◽

Soluble Sugars ◽

Potassium Nitrate ◽

Plant Production ◽

Global Constraints ◽

Physiological Status ◽

Severe Drought ◽

Stress Indicators ◽

Spinacia Oleracea L

Drought and low amounts of mineral nutrients in the soil are the two leading global constraints in arid and semiarid regions. Their detrimental effects on soils and crops can be alleviated by applying controlled release and biodegradable fertilizers to better and sustain the crops. On a global scale, spinach (Spinacia oleracea L.) is an essential leafy green vegetable that is biologically considered a reliable source of essential nutrients and minerals for human health. A comprehensive approach is needed to manage water stress to mitigate the impacts of stress-caused damage and to examine this for better and increased plant production. An experiment was conducted using potassium-nitrate-containing chitosan/montmorillonite microparticles (150 mg) under mild and severe drought stress (MDS: 50% and SDS: 35% FC, respectively). The treatments include control (no KNO3 and 70% FC as normal irrigation (NI)), KNO3 + NI, 50% FC as mild drought stress (MDS), KNO3 + MDS, 35% FC as severe drought stress (SDS) and KNO3 + SDS. Results revealed that drought stress decreased all studied physiological parameters and increased oxidative stress indicators in spinach. Applying KN significantly increased root (122%) and shoot length (4%), shoot fresh weight (32%) and shoot dry weight (71%), chlorophyll a (88%), carotenoids (39%), total soluble proteins (50%), soluble sugars (51%), potassium (80%), and phosphorous (32%) concentrations over No KN at severe drought. While stress indicators, like glycine betaine, malondialdehyde, hydrogen peroxide, electrolyte leakage, peroxidase, superoxide dismutase, and ascorbic acid levels, were increased in stress. Treatment KN was proved efficient and effective in improving spinach physiological status in both MDS and SDS.

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Plant growth promoting rhizobacteria alleviates drought stress in potato in response to suppressive oxidative stress and antioxidant enzymes activities

Scientific Reports ◽

10.1038/s41598-020-73489-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Tahira Batool ◽

Shafaqat Ali ◽

Mahmoud F. Seleiman ◽

Naima Huma Naveed ◽

Aamir Ali ◽

...

Keyword(s):

Growth Rate ◽

Drought Stress ◽

Plant Growth ◽

Relative Growth Rate ◽

Soluble Sugars ◽

Plant Growth Promoting Rhizobacteria ◽

Growth And Yield ◽

Relative Growth ◽

Relative Water ◽

Plant Growth Promoting

Abstract Maintenance of plant physiological functions under drought stress is normally considered a positive feature as it indicates sustained plant health and growth. This study was conducted to investigate whether plant growth-promoting rhizobacteria (PGPR) Bacillus subtilis HAS31 has potential to maintain potato growth and yield under drought stress. We analyzed trends of chlorophyll concentration, photosynthesis process, relative water content, osmolytes, antioxidants enzymes and oxidative stress, relative growth rate, tuber and aboveground biomass production in two potato varieties, Santae (drought-tolerant) and PRI-Red (drought-sensitive). Plants of both genotypes were treated with 100 g of HAS31 inoculant at 10 days after germination and exposed to different soil relative water contents (SRWC), including 80 ± 5% (well watered), 60 ± 5% (moderate stress) and 40 ± 5% SRWC (severe stress) for 7 days at tuber initiation stage (30 days after germination). The drought stress reduced plant relative growth rate, biomass production, leaf area, number of leaves and tubers, tuber weight, and final yield. The drought-stressed plants showed decline in chlorophyll contents, membrane stability, leaf relative water contents and photosynthetic rate. Under drought stress, enzymatic activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), contents of total soluble sugars, soluble proteins and proline increased. The application of PGPR reduced the impact of drought and maintained higher growth and physio-chemical traits of the plants. The plants with PGPR application showed higher relative growth rate, dry matter production, leaf area, number of tubers, tuber weight and yield as compared to plants without PGPR. The PGPR-HAS31 treated plants maintained higher photosynthetic process, contents of chlorophyll, soluble proteins, total soluble sugars, and enzymatic activities of CAT, POD and SOD as compared to plants without PGPR. The results of the study suggest that plant growth regulators have ability to sustain growth and yield of potato under drought stress by maintaining physiological functions of the plants.

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Licorice (Glycyrrhiza glabra)—Growth and Phytochemical Compound Secretion in Degraded Lands under Drought Stress

Sustainability ◽

10.3390/su13052923 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2923

Author(s):

Botir Khaitov ◽

Munisa Urmonova ◽

Aziz Karimov ◽

Botirjon Sulaymonov ◽

Kholik Allanov ◽

...

Keyword(s):

Drought Stress ◽

Water Deficit ◽

Background Field ◽

Field Trials ◽

Glycyrrhiza Glabra ◽

Agricultural System ◽

Positive Effects ◽

Relative Water ◽

Moderate Drought ◽

Four Levels

Water deficiency restricts plant productivity, while excessive soil moisture may also have an adverse impact. In light of this background, field trials were conducted in secondary saline soil (EC 6.5 dS m−1) at the experimental station of Tashkent State Agrarian University (TSAU), Uzbekistan to determine drought tolerance of licorice (Glycyrrhiza glabra) by exposure to four levels of water deficit, namely control (70–80%), moderate (50–60%), strong (30–40%) and intense (10–20%) relative water content (WC) in the soil. The moderate drought stress exhibited positive effects on the morphological and physiological parameters of licorice, and was considered to be the most suitable water regime for licorice cultivation. Plant growth under the 50–60% WC treatment was slightly higher as compared to 70–80% WC treatment, exhibiting weak water deficit promotes licorice growth, root yield and secondary metabolite production. In particular, secondary metabolites i.e., ash, glycyrrhizic acid, extractive compounds and flavonoids, tended to increase under moderate water deficit, however further drought intensification brought a sharp decline of these values. These results contribute to the development of licorice cultivation technologies in arid regions and the most important consideration is the restoration of ecological and economical functions of the dryland agricultural system.

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Biochar Mediated-Alleviation of Chromium Stress and Growth Improvement of Different Maize Cultivars in Tannery Polluted Soils

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094461 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4461

Author(s):

Muhammad Asaad Bashir ◽

Xiukang Wang ◽

Muhammad Naveed ◽

Adnan Mustafa ◽

Sobia Ashraf ◽

...

Keyword(s):

Soluble Sugars ◽

Cultivar Differences ◽

Leather Industry ◽

Polluted Soils ◽

Chlorophyll Pigments ◽

Growth Physiology ◽

Maize Cultivars ◽

Physiology And Biochemistry ◽

Cr Toxicity ◽

Relative Water

Soil pollution with heavy metal is a serious problem across the globe and is on the rise due to the current intensification of chemical industry. The leather industry is one of them, discharging chromium (Cr) in huge quantities during the process of leather tanning and polluting the nearby land and water resources, resulting in deterioration of plant growth. In this study, the effects of biochar application at the rate of 3% were studied on four maize cultivars, namely NK-8441, P-1543, NK-8711, and FH-985, grown in two different tannery polluted Kasur (K) and Sialkot (S) soils. Maize plants were harvested at vegetative growth and results showed that Cr toxicity adversely not only affected their growth, physiology, and biochemistry, but also accumulated in their tissues. However, the level of Cr toxicity, accumulation, and its influence on maize cultivars varied greatly in both soils. In this pot experiment, biochar application played a crucial role in lessening the Cr toxicity level, resulting in significant increase in plant height, biomass (fresh and dry), leaf area, chlorophyll pigments, photosynthesis, and relative water content (RWC) over treatment set as a control. However, applied biochar significantly decreased the electrolyte leakage (EL), antioxidant enzymes, lipid peroxidation, proline content, soluble sugars, and available fraction of Cr in soil as well as Cr (VI and III) concentration in root and shoot tissues of maize plant. In addition to this, maize cultivar differences were also found in relation to their tolerance to Cr toxicity and cultivar P-1543 performed better over other cultivars in both soils. In conclusion, biochar application in tannery polluted soils could be an efficient ecofriendly approach to reduce the Cr toxicity and to promote plant health and growth.

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Relationships between physiological traits and productivity of sugarcane in response to water deficit

The Journal of Agricultural Science ◽

10.1017/s0021859612000834 ◽

2012 ◽

Vol 152 (1) ◽

pp. 104-118 ◽

Cited By ~ 16

Author(s):

M. DE A. SILVA ◽

J. L. JIFON ◽

J. A. G. DA SILVA ◽

C. M. DOS SANTOS ◽

V. SHARMA

Keyword(s):

Water Deficit ◽

Field Studies ◽

Water Deficit Stress ◽

Chlorophyll Contents ◽

Physiological Variables ◽

Drought Tolerant ◽

Relative Water ◽

Leaf Relative Water Content ◽

Sugarcane Productivity ◽

Response To Water

SUMMARYThe relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (Fv/Fm), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with Fv/Fm, SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.

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Adaptive responses to drought of two Retama raetam subspecies from Tunisia

Journal of Plant Ecology ◽

10.1093/jpe/rtab007 ◽

2021 ◽

Author(s):

Ricardo GIL ◽

Dhikra ZAYOUD ◽

Zeineb OUERGHI ◽

Monica BOSCAIU ◽

Oscar VICENTE ◽

...

Keyword(s):

Drought Stress ◽

Glycine Betaine ◽

Soluble Sugars ◽

Co2 Concentration ◽

Photosynthetic Parameters ◽

Adaptive Responses ◽

Retama Raetam ◽

Physiological Adaptations ◽

Use Efficiency ◽

Desert Climate

Abstract Aims The survival and ecological distribution of plants in arid habitats are mainly conditioned by water availability and physiological adaptations to withstand drought. In the present study, we have compared the physiological responses to drought of two Retama raetam (retama) subspecies from Tunisia, one of them living under the desert climate (subsp. raetam) and the other one growing on the coast (subsp. bovei). Methods To physiologically characterize the two R. raetam subspecies, and to elucidate their main mechanisms underlying their tolerance to drought stress, parameters related to seed germination, growth, photosynthesis (net photosynthetic rate, intracellular CO2 concentration, transpiration rate, stomatal conductance and water use efficiency), and accumulation of osmolytes (proline, glycine betaine and soluble sugars) were determined in four-month-old plants subjected to stress for up to one month. Important findings Drought signiﬁcantly inhibited germination, growth, and all the evaluated photosynthetic parameters. Plants of R. raetam subsp. bovei were severely affected by drought after three weeks of treatment when photosynthesis rates were up to 7-fold lower than in the controls. At the same time, proline and glycine betaine significantly accumulated compared to the irrigated controls, but much less than in R. raetam subsp. raetam; in the latter subspecies, proline and glycine betaine increased to levels 24-fold and 6-fold higher, respectively, than in the corresponding controls. In summary, the population living in the desert region exhibited stronger tolerance to drought stress than that adapted to the semiarid littoral climate, suggesting that tolerance in R. raetam is dependent on accumulation of osmolytes.

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Salt-tolerance screening in Limonium sinuatum varieties with different flower colors

Scientific Reports ◽

10.1038/s41598-021-93974-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaojing Xu ◽

Yingli Zhou ◽

Ping Mi ◽

Baoshan Wang ◽

Fang Yuan

Keyword(s):

Salt Tolerance ◽

Photosynthetic Rate ◽

Large Scale ◽

Soluble Sugars ◽

Dry Weight ◽

Salt Gland ◽

Salt Glands ◽

Chlorophyll Contents ◽

Relative Water ◽

Whole Plants

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.

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Methionine-induced regulation of growth, secondary metabolites and oxidative defense system in sunflower (Helianthus annuus L.) plants subjected to water deficit stress

PLoS ONE ◽

10.1371/journal.pone.0259585 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0259585

Author(s):

Gull Mehak ◽

Nudrat Aisha Akram ◽

Muhammad Ashraf ◽

Prashant Kaushik ◽

Mohamed A. El-Sheikh ◽

...

Keyword(s):

Drought Stress ◽

Helianthus Annuus ◽

Water Deficit ◽

Soluble Sugars ◽

Foliar Spray ◽

Shoot Length ◽

Stress Conditions ◽

Growth And Yield ◽

Water Deficit Stress ◽

Growth Stages

Optimum water availability at different growth stages is one the major prerequisites of best growth and yield production of plants. Exogenous application of plant growth regulators considered effective for normal functioning of plants under water-deficit conditions. A study was conducted to examine the influence of exogenously applied L-methionine on sunflower (Helianthus annuus L.) plants grown under water-deficit conditions. Twenty-five-day old seedlings of four sunflower cultivars, FH331, FH572, FH652 and FH623 were exposed to control (100% F.C.) and drought stress (60% F.C.) conditions. After 30-day of drought stress, L-methionine (Met; 20 mg/L) was applied as a foliar spray to control and drought stressed plants. Water deficit stress significantly reduced shoot fresh and dry weights shoot and root lengths, and chlorophyll a content in all four cultivars. While a significant increase was observed due to water deficiency in relative membrane permeability (RMP), malondialdehyde (MDA), total soluble proteins (TSP), total soluble sugars (TSS), ascorbic acid (AsA) and activity of peroxidase (POD). Although, exogenously applied Met was effective in decreasing RMP, MDA and H2O2 contents, it increased the shoot fresh weight, shoot length, chlorophyll a, chlorophyll a/b ratio, proline contents and the activities of SOD, POD and CAT enzymes in all four cultivars under water deficit stress. No change in AsA and total phenolics was observed due to foliar-applied Met under water stress conditions. Of all sunflower cultivars, cv. FH-572 was the highest and cv. FH-652 the lowest of all four cultivars in shoot fresh and dry weights as well as shoot length under drought stress conditions. Overall, foliar applied L-methionine was effective in improving the drought stress tolerance of sunflower plants that was found to be positively associated with Met induced improved growth attributes and reduced RMP, MDA and H2O2 contents under water deficit conditions.

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