scholarly journals Effect of Seed Inoculation on Alfalfa Tolerance to Water Deficit Stress

2017 ◽  
Vol 45 (1) ◽  
pp. 82-88
Author(s):  
Mahnaz ZAFARI ◽  
Ali EBADI ◽  
Sodabeh JAHANBAKHSH GODEHKAHRIZ

Water deficit is one of the most important environmental stresses that adversely affect crop growth and production and mycorrhizal fungi and symbiotic bacteria have important role in resistance to drought stress. The effect of biofertilizers on alfalfa stress tolerance was studied at the greenhouse condition. Treatments comprised three water-deficit stresses (35%, 55% and 75% of field capacity) and four seeds inoculations (Glomus mosseae, Sinorhizobium meliloti, G. mosseae + S. meliloti and non-inoculated). Water-deficit stress decrease cell membrane stability (39%), total Chl (24.05%), carotenoid (35.55%), quantum yield (50.64%) and forage yield (28.20%), while increased the proline and soluble sugars content (68.55 and 46.53% respectively) and osmotic potential (45.84%). The inoculation of seeds increased the capability of the plants in counteracting the stress, so that the production of compatible solutes was increased and the photosynthetic indices, proline, osmotic potential, membrane stability and forage yield were improved by seed inoculation. Mycorrhiza improved photosynthetic indexes and proline, but bacteria had more efficacy on membrane stability and forage yield. However, double inoculation due to the synergistic effect of mycorrhiza and Sinorhizobium, had the greatest effect than Solitary inoculation. Our results suggest that biofertilized alfalfa plants were better adapted than non- biofertilized ones to cope with water deficit.

2013 ◽  
Vol 64 (3) ◽  
pp. 254 ◽  
Author(s):  
Aida Rouached ◽  
Inès Slama ◽  
Walid Zorrig ◽  
Asma Jdey ◽  
Caroline Cukier ◽  
...  

The response patterns during water deficit stress and subsequent recovery of two forage species, Medicago truncatula and Sulla carnosa, were studied. After germination and pre-treatment, seedlings were individually cultivated for two months under two irrigation modes: 100% and 33% of field capacity. Measured parameters were plant growth, water relations, leaf osmotic potential, lipid peroxidation, and leaf inorganic (Na+ and K+) and organic (proline and soluble sugars) solute contents, as well as delta-1-pyrroline-5-carboxylate synthase (P5CS) and proline dehydrogenase (PDH) activities. Our results showed that under control conditions, and in contrast to roots, no significant differences were observed in shoot biomass production between the two species. However, when subjected to water-deficit stress, M. truncatula appeared to be more tolerant than S. carnosa (reduction by 50 and 70%, respectively). In the two studied species, water-deficit stress led to an increase in root/shoot ratio and leaf proline and soluble sugar contents, and a decrease in leaf osmotic potential. Enzymatic assay revealed that in the two species, P5CS activity was stimulated whereas that of PDH was inhibited under stress conditions. Despite greater accumulation of proline, sugar, and potassium in leaves of S. carnosa, M. truncatula was more tolerant to water deficit. This was essentially due to its capacity to control tissue hydration and water-use efficiency, in addition to its greater ability to protect membrane integrity. Following stress relief, M. truncatula and S. carnosa showed partial re-establishment of growth capacity.


Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 149
Author(s):  
Mohammed Bouskout ◽  
Mohammed Bourhia ◽  
Mohamed Najib Al Feddy ◽  
Hanane Dounas ◽  
Ahmad Mohammad Salamatullah ◽  
...  

Agricultural yields are under constant jeopardy as climate change and abiotic pressures spread worldwide. Using rhizospheric microbes as biostimulants/biofertilizers is one of the best ways to improve agro-agriculture in the face of these things. The purpose of this experiment was to investigate whether a native arbuscular mycorrhizal fungi inoculum (AMF-complex) might improve caper (Capparis spinosa) seedlings’ nutritional status, their morphological/growth performance and photosynthetic efficiency under water-deficit stress (WDS). Thus, caper plantlets inoculated with or without an AMF complex (+AMF and −AMF, respectively) were grown under three gradually increasing WDS regimes, i.e., 75, 50 and 25% of field capacity (FC). Overall, measurements of morphological traits, biomass production and nutrient uptake (particularly P, K+, Mg2+, Fe2+ and Zn2+) showed that mycorrhizal fungi inoculation increased these variables significantly, notably in moderate and severe WDS conditions. The increased WDS levels reduced the photochemical efficiency indices (Fv/Fm and Fv/Fo) in −AMF plants, while AMF-complex application significantly augmented these parameters. Furthermore, the photosynthetic pigments content was substantially higher in +AMF seedlings than −AMF controls at all the WDS levels. Favorably, at 25% FC, AMF-colonized plants produce approximately twice as many carotenoids as non-colonized ones. In conclusion, AMF inoculation seems to be a powerful eco-engineering strategy for improving the caper seedling growth rate and drought tolerance in harsh environments.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259585
Author(s):  
Gull Mehak ◽  
Nudrat Aisha Akram ◽  
Muhammad Ashraf ◽  
Prashant Kaushik ◽  
Mohamed A. El-Sheikh ◽  
...  

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.


2017 ◽  
Vol 9 (12) ◽  
pp. 259
Author(s):  
Amin Namdari ◽  
Abolfazl Baghbani

Due to low rainfall at early autumn, smooth vetch seedling growth in rain-fed lands often is limited by water deficit stress yet the data regarding the reactions of smooth vetch to water deficit at early growth stages are pretty rare. The objective of current study was to examine possibility of using priming treatments (hydro priming and priming salicylic acid) to alleviate the inhibitory effect of water deficiency during early growth of Smooth Vetch. In this respect, seeds were soaked in distilled water (hydro priming) or 0.5 mM solution of SA for 36 h at 10 °C then dried back to original moisture content. Pots were irrigated for 25 days at four levels of available water containing field capacity (FC), 75% FC, 50% FC and 25% FC. In general, seedling emergence and early growth were markedly limited by increasing water deficiency. However, priming treatments particularly with SA caused considerable improvement in either emergence or growth of seedlings (dry weight, length). The obtained results showed that primed samples exhibited higher accumulation of proline, glycine betaine (GB) under all levels of available water except 100% FC and also higher total soluble sugars (TSS) and trehalose under severe water deficit (25% FC). SA primed samples had higher relative water content especially under higher levels of water deficiency. The more balanced water status within SA primed samples also was accompanied with higher accumulation of proline and glycine betaine. There were significant differences between two priming treatments in terms of proline and GB content within seedlings and SA priming considerably increased proline and GB accumulation. In contrast to proline and GB, TSS and trehalose content wasn’t influenced by SA treatment and both hydro and SA primed samples showed statistically similar quantities.


1993 ◽  
Vol 118 (2) ◽  
pp. 274-279 ◽  
Author(s):  
Baolin Zhang ◽  
Douglas D. Archbold

A comparative study was performed to elucidate changes in the water relations of Fragaria chiloensis (L.) Duch. `BSP14' (FC) and F. virginiana (L.) Duch. `NCC85-13V' (FV), grown in containers in a greenhouse, in response to imposed water deficit stress and subsequent recovery. At incipient wilting, a reduction in osmotic potential at full turgor (Ψπ100 of 0.42 MPa occurred in leaves of FC, while no change was found in FV. Leaf water potential (Ψ) isotherms revealed that as leaf Ψ and relative water content (RWC) declined, stressed FC plants maintained a higher turgor potential (ΨP) and lower osmotic potential (Ψπ) than nonstressed (control) plants, while there was no effect of drought stress on these relationships in the FV plants. From the isotherms, turgor loss was estimated to occur at a lower leaf Ψ and RWC in stressed FC plants than either in control FC plants or stressed and control FV plants. During a diurnal phase 36 hours after wilting, leaf Ψ, Ψπ and RWC of the FC selection were generally lower in stressed than in control plants, with differences ranging from 0.14 to 0.74 MPa, 0.28 to 0.47 MPa, and 1% to 8%, respectively. In the FV selection, Ψπ was 0.09 to 0.31 MPa lower in stressed than in control leaves, while the other characteristics were not affected. Leaf ΨP, of stressed FC plants was 0.09 to 0.27 MPa higher than controls during the dark period, but was similar during the day. When plants of both species were grown and stressed in the same container, FV plants wilted ≈4 days earlier than FC plants, and foliar Ψπ100 of FC was 0.35 MPa lower than that of FV at incipient wilting. The isothermal relationships between leaf Ψ and Ψπ100 indicated FC had a Ψπ100 ≈ 0.25 MPa lower than FV at a Ψ <1.5 MPa. This study provided evidence for greater osmotic adjustment in response to imposed water deficit stress in a selection of F. chiloensis than in one of F. virginiana.


2018 ◽  
Vol 71 (2) ◽  
Author(s):  
Mehdi Yosefi ◽  
Shahram Sharafzadeh ◽  
Forood Bazrafshan ◽  
Mahdi Zare ◽  
Bahram Amiri

Precise and appropriate management of farmland for a cotton crop to reach the highest water use efficiency with a low water supply and an acceptable yield is required in arid- and semiarid regions. This study in Iran aimed to find the most appropriate concentration of jasmonic acid (JA) and the best stage for application to cope with any negative impacts of water deficit stress. A split-plot factorial experiment based on a randomized complete block design with three replications was used in 2 consecutive years (2016–2017). Two irrigation intervals of 10 and 20 days were used, with four concentrations of JA (0, 25, 50, and 100 mg L<sup>−1</sup> ) and applications at three crop stages (vegetative, reproductive, and vegetative and reproductive together). The final results showed that the 20-day interval significantly decreased relative water content, the quantity of cotton, cotton yield and its related traits including boll number per plant, the 1,000-seed weight, seed cotton yield, lint yield, and lint percentage. It also increased the content of proline and soluble sugars. The 50-mg L<sup>−1</sup> concentration of JA applied at the vegetative-reproductive stages appropriately mitigated the negative effects of water deficit. These results are of practical application for farmers in arid- and semiarid regions with low water supply when irrigating cotton lands in order to reach an acceptable cotton yield.


2021 ◽  
Vol 12 ◽  
Author(s):  
Arruje Hameed ◽  
Tahir Farooq ◽  
Amjad Hameed ◽  
Munir Ahmad Sheikh

Water-deficit stress negatively affects seed germination, seedling development, and plant growth by disrupting cellular and metabolic functions, reducing the productivity and yield of field crops. In this study, sodium silicate (SS) has been employed as a seed priming agent for acclimation to mild water-deficit stress by invoking priming memory in wheat plants. In pot experiments, the SS-primed (20, 40, and 60 mM) and non-primed control seeds were allowed to grow under normal and mild water-deficit conditions. Subsequently, known methods were followed for physiological and biochemical studies using flag leaves of 98-day mature wheat plants. The antioxidant and hydrolytic enzymes were upregulated, while proteins, reducing sugars, total sugars, and glycine betaine increased significantly in the flag leaves of wheat plants originated from SS-treated seeds compared to the control under mild water-deficit stress. Significant decreases in the malondialdehyde (MDA) and proline contents suggested a controlled production of reactive oxygen species, which resulted in enhanced cell membrane stability. The SS priming induced a significant enhancement in yield, plant biomass, and 100-grain weight of wheat plants under water-deficit stress. The improvement in the yield parameters indicated the induction of Si-mediated stress acclimation in SS-primed seeds that elicited water-deficit tolerance until the maturity of plants, ensuring sustainable productivity of climate-smart plants.


2021 ◽  
Author(s):  
Fatemeh Ebrahimi ◽  
Amin Salehi ◽  
Mohsen Movahedi Dehnavi ◽  
Amin Mirshekari ◽  
Mohammad Hamidian ◽  
...  

Abstract BackgroundWater-deficit stress is one of the most important sources of damage to crop production worldwide. Adopting appropriate varieties using soil microorganisms such as arbuscular mycorrhiza(AM) can significantly reduce theadverseeffectsofwater deficiency.This study is aimed to evaluate the role of Funneliformismosseaeon nutrients uptake and some physiological traits of two chamomile varieties namely Bodgold (Bod) and Soroksári(Sor) under water-deficit stress. The pot experiment was performed in a hydroponic system within a completely randomized design considering four replications. Three levels of water-deficit stress (PEG 6000) were taken into account at water potentials of -0.4 and -0.8MPa. The second factor was AM inoculation.ResultsWater-deficit stress significantly reduced the uptake of macro-nutrients (N, P, and K) and micro-nutrients (Fe, Cu, Mn, and Zn) in the shoots and roots. Moreover, the level of osmolytes (total soluble sugars and proline) and the activity of antioxidant enzymes in the shoots of both varieties increased under water-deficit stress. In the case of Sor variety, the level of these compounds was more satisfactory. AM improved plant nutrition uptake and osmolyte contents while enhancing antioxidant enzymes and reducing theadverseeffectsofwater-deficit stress. Under water-deficit stress, the growth and total dry weight improved upon AM inoculation. ConclusionsIn general, inoculation of chamomile with AM balanced the uptake of nutrients increased the level of osmolytes, antioxidant enzymes, and hence improved plant characteristics under water-deficit stress in both varieties, however, it was more effective in reducing stress damages in Sor variety.


2019 ◽  
Vol 46 (1) ◽  
pp. 93 ◽  
Author(s):  
Dorothy A. Onyango ◽  
Fredrickson Entila ◽  
Mathew M. Dida ◽  
Abdelbagi M. Ismail ◽  
Khady N. Drame

Iron (Fe) is a fundamental element involved in various plant metabolic processes. However, when Fe uptake is excessive, it becomes toxic to the plant and disrupts cellular homeostasis. The aim of this study was to determine the physiological and biochemical mechanisms underlying tolerance to Fe toxicity in contrasting rice varieties adapted to African environments. Four varieties (CK801 and Suakoko 8 (tolerant), Supa and IR64 (sensitive)) selected from our previous work were analysed in more detail, and the first part of this study reports morphological, physiological and biochemical responses induced by Fe toxicity in these four varieties. Morphological (shoot length, root length, number of lateral roots), physiological (photosynthesis rate, stomatal conductance, transpiration rate, fluorescence, relative water content and cell membrane stability) and biochemical (tissue Fe, chlorophyll pigments, soluble sugars, protein and starch) traits were measured, as appropriate, on both shoot and root tissues and at different time points during the stress period. Fe toxicity significantly (P≤0.05) reduced growth and metabolism of all the four varieties. Tolerant varieties showed more lateral roots than the sensitive ones, under Fe toxic conditions as well as higher photosynthesis rate, chlorophyll content and cell membrane stability. Strong dilution of Fe concentration in cells was identified, as one of the additional tolerance mechanisms used by CK801, whereas Suakoko 8 mainly used strong mobilisation of carbohydrates at the early stage of the stress period to anticipate metabolite shortage. Traits associated with Fe toxicity tolerance in this study could be specifically targeted in trait-based breeding programs of superior lowland rice varieties tolerant of Fe toxicity.


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