Germinating Barley Seeds Research Articles

Preparation of copper glycinate and study of its effect on the germination of winter barley seeds

We analyzed the encrustation of winter barley seeds, which includes its preliminary treatment with cuprum glycinate, with the purpose of increasing yield and biochemical indicators of grain, and also improving the ecological condition of the soil. The objective of the research was to select methods for the synthesis of cuprum glycinate, study its chemical composition and the possibility of using this compound as a chelated micro-fertilizer for pre-sowing encrustation of winter barley seed as part of a tank mixture. Two well-known synthesis methods were used to obtain cuprum glycinate. The first method was the interaction between CuO with a solution of glycine during heating, during which pink metallic copper inclusions were noticed in the mixture of reaction products. It was found that it is expedient to synthesize the glycine complex of cuprum by the reaction of a suspension of Cu2CO3(OH)2 with glycine during heating (the yield is 97%), since a complex compound Cu(NH2CH2COO)2•H2O of sufficient purity is formed. The composition of the synthesized substance and the confirmation of the formula of the compound Cu(NH2CH2COO)2•H2O were obtained by determining the infrared and the atomic absorption spectrum of the aqueous solution. Based on the obtained differences in the atomic absorption spectra of the synthesized copper sulfate and copper glycinate the formation of the latter was confirmed. The IR spectrum confirms the formula of the complex compound and the formation of strong covalent bonds between the metal cation and the ligands. The study of the effect of cuprum glycinate on the germination of winter barley Tutankhamun seeds was carried out in comparison with the similar effect of a complex compound of cuprum with ethylenediaminetetraacetate. The study of the influence of cuprum glycinate on the germination of winter barley revealed positive results in which the germination exceeded the control by 9–27%. Winter barley seeds treated with distilled water served as a control. Treatment of winter barley seeds with an aqueous solution of cuprum glycinate in the amount of 20 g of cuprum per 1 ton of grain led to better germination than pre-treatment of seeds with a twice concentrated corresponding solution. Treatment with a complex compound of copper with ethylenediaminetetraacetate had no significant effect on the germination and characteristics of sprouts. The results of laboratory studies confirmed the feasibility of using complex compounds of biometal copper with organic chelating ligands as microfertilizers for pre-sowing seed encrustation, as they have high stability and sufficient solubility in water, are non-toxic, are better absorbed by plants and are considered cost-effective and environmentally safe.

The Effect of the Application of Inorganic Fertilizers under Winter Barley in the Karabakh Region

In terms of distribution and production in the world, barley ranks 4th among grains after wheat, rice and corn. The widespread use of barley in various fields (food, feed, brewing, etc.) distinguishes it from other cereals. Barley is an unpretentious, but at the same time valuable and cost-effective plant. Its ripening in a relatively short growing season, resistance to high temperatures, drought and salinity make it possible to cultivate it in many countries of the world. Barley grain contains 50-60% starch, 10-14% protein, 5.5% fiber and 2.1% fat. To obtain a high yield from autumn barley, it is necessary to fully satisfy its need for external life factors and create optimal living conditions; for this, it is necessary to carry out the necessary cultivation work in a timely manner. For the germination of autumn barley seeds, the minimum temperature should be +1°, +2°. Optimum temperature 20-25°C, maximum +35°, +40°C. Compared to winter wheat, autumn barley is less resistant to negative temperatures and winter. Therefore, it is impossible to grow it in regions with very harsh winters. The barley varieties cultivated in Azerbaijan tolerate temperatures of −14°, −16°C. The application of phosphorus fertilizers under the plow in the fall and as top dressing significantly increases the winter hardiness of plants.

Effects of Lactone- and Ketone-Brassinosteroids of the 28-Homobrassinolide Series on Barley Plants under Water Deficit.

The aim of this work was to study the ability of 28-homobrassinolide (HBL) and 28-homocastasterone (HCS) to increase the resistance of barley (Hordeum vulgare L.) plants to drought and to alter their endogenous brassinosteroid status. Germinated barley seeds were treated with 0.1 nM HBL or HCS solutions for two hours. A water deficit was created by stopping the watering of 7-day-old plants for the next two weeks. Plants responded to drought through growth inhibition, impaired water status, increased lipid peroxidation, differential effects on antioxidant enzymes, intense proline accumulation, altered expression of genes involved in metabolism, and decreased endogenous contents of hormones (28-homobrassinolide, B-ketones, and B-lactones). Pretreatment of plants with HBL reduced the inhibitory effect of drought on fresh and dry biomass accumulation and relative water content, whereas HCS partially reversed the negative effect of drought on fresh biomass accumulation, reduced the intensity of lipid peroxidation, and increased the osmotic potential. Compared with drought stress alone, pretreatment of plants with HCS or HBL followed by drought increased superoxide dismutase activity sevenfold or threefold and catalase activity (by 36%). The short-term action of HBL and HCS in subsequent drought conditions partially restored the endogenous B-ketone and B-lactone contents. Thus, the steroidal phytohormones HBL and HCS increased barley plant resistance to subsequent drought, showing some specificity of action.

Assessment of Phytotoxicity and Efficiency of Date Palm Waste Compost on Barley Seeds Germination and Seedlings Growth

ABSTRACT The valorization of date palm wastes as bioresources has received little attention. In this context, the feasibility of date palm waste valorization through composting and the application effects on barley plants production under control condition was investigated. The principal requirements for compost to be safely used are stability and maturity that refer, respectively, to the microbial biomass activity’s level, germination tests, and plant growth bioassays or phytotoxicity. Indeed, the phytotoxicity of composted date palm waste used for seed germination and seedling growth bioassays was researched. The finished compost values of the C/N ratio were 15.36 and 18.58%, 1.21%, 0.54%, and 0.95% for total organic carbon, N, P, and K contents, respectively. The concentration of heavy metals and microelements were lower and met the requirement established by national standards. Moreover, the end product was free from harmful pathogens like Salmonella, Escherichia coli, total coliforms, and fecal coliform bacteria. Application of compost extract (especially 25%, 50%, and 75%) did not affect barley seed germination, stimulated hypocotyl and radicle growth and is characterized by a GI exceeding 90%, demonstrating its stability and lack of phytotoxic effect. Moreover, compost promotes plant growth, improved physiological parameters, photosynthetic pigments, and plant biomass. According to the results, the prepared compost especially at the dose T3 (soil amended with 30 t/ha) increased the nutrients availability and uptake which may be the reason for an increase in photosynthetic activity, chlorophyll synthesis, and dry matter accumulation. Composting may well represent an acceptable solution for disposing of date palm waste and be of great interest to sustainable agriculture in Tunisia oasis ecosystems.

Physiological Quality of Treated and Stored Barley Seeds

Industrial seed treatment (IST) is used in some grain crops. However, the products used often impair the quality of seeds, especially insecticides. In the case of barley seeds, investigative studies on the use of IST are scarce. The present study aimed to evaluate the influence of IST with the fungicide (Iprodione) and insecticide (Thiamethoxan) products, mixed or not, on the physiological quality of barley seeds, before and after storage for two months. A completely randomized design was used, in a 4x2 factorial scheme, with four replications. The treatments consisted of four combinations of applications carried out via IST on barley seeds, of chemical pesticides (fungicide/insecticide), alone or in mixtures, as follows: {T1 – fungicide Iprodione (Rovral); T2 – Thiamethoxan insecticide (Cruizer); T3 – mixture of fungicide/insecticide products (Iprodione + Thiamethoxan); T4 – Control)}, submitted to storage for two months, with evaluations carried out at T0 (treated and analyzed seeds) and T1 (treated seeds stored for 60 days). The following tests were carried out: water content, germination, first count, accelerated aging, seedling length, seedling dry mass. It was concluded that the germination of barley seeds treated with the fungicide Iprodione (Rovral®) and the insecticide Thiamethoxan (Cruizer®), alone and in a mixture applied via IST, maintained the physiological quality of the seeds within the standards for commercialization until 60 days of storage. The use of the insecticide Thiamethoxan (Cruizer®) via IST showed greater damage to the physiology of barley seeds during storage (60 days), applied alone or in a mixture with the fungicide Iprodione (Rovral ®).

Toxic effect of elements on the germination and initial development of barley seeds (Hordeum vulgare L.)

Barley (Hordeum vulgare) is an agricultural vegetable from the Poaceae family used in food and beer production. The study aimed to evaluate the toxic effect of Aluminum (Al) and Copper (Cu) on germination and initial development in barley seeds cultivar KWS Irina. Different concentrations (0, 35, 85 and 125 mg L-1) of aqueous solution of Al and Cu were produced from their chlorides. The toxicity experiment was carried out in a germination box maintained in a germination chamber with a 12-h photoperiod. After 15 days of germination, the seedlings were measured using a millimetric ruler (cm) where they were evaluated for plant length, root length, and fresh and dry mass of plant and root determined on a digital analytical scale (g). Barley seedlings cultivar KWS Irina demonstrated to be intolerant to concentrations of the toxic elements Al and Cu in all plant parameters analyzed, except for plant dry mass. Future studies should be carried out comparing the initial and reproductive development of this barley cultivar in terms of the presence and absence of toxic elements.

Endophytic Fungi from Salt Adapted Plants Confer Salt Tolerance in Barley

Endophytic fungi are known to improve plant tolerance under stressful conditions including salt stress. Considering this, the endophytic fungi, Alternaria chlamydospora, Embellisia phragmospora, Phomabetae, Chaetomium coarctatum, Fusarium equiseti and Fusarium graminearum, was isolated from roots of plants growing in salt environments and then, evaluated for their contribution in conferring salt stress tolerance in barley plants. The influence of inoculation with endophytic fungi, on germination, root and shoot lengths of barley seeds under different NaCl levels (0, 200, 300 and 400 mM) was investigated. Results showed that seed germination and root and shoot lengths were higher in seeds pretreated with endophytic fungi cultures than their controls under saline conditions. This study suggests that the tested endophytic fungi might be applied as a strategy for mitigating the stress-imposed salt in plants and, therefore, improving crop growth and productivity.

Effect of Acarus siro L. infestation on germination of wheat and barley seeds under laboratory conditions ​

A laboratory study was conducted to assess the effect of mite infestation with the grain on the germination of wheat (IPA-99 variety) and barley (Al-Khair variety) seeds. The mite was diagnosed in stored and infested wheat and barley seeds as grain mite (cheese mite) Acarus siro L. The results showed that infestation of wheat and barley seeds with A. siro had a significant impact on their germination percentage, whether the seeds were unwashed or washed. The percentage of infestation and germination in wheat seed samples reached 20, 40, 60, 80, and 100 reached 45.00%, 80.00%, 91.67%, 93.75%, and 96.00% with a germination rate of 55.00%, 20.00%, 8.33%, 6.25%, and 4.00% for unwashed seeds, respectively. For washed seeds, the infestation rate was 40.00%, 62.50%, 80.00%, 85.00%, and 90.00% with a germination rate of 60.00%, 37.50%, 20.00%, 15.00%, and 10.00%, respectively. Whereas, for barley seeds, the percentage of infestation and germination in the samples 20, 40, 60, 80, and 100 reached 35.00%, 72.50%, 83.33%, 88.75%, and 94.00% with a germination rate of 65.00%, 27.50%, 16.67%, 11.25%, and 6.00% for unwashed seeds, respectively. For washed seeds, the infestation rate was 25.00%, 57.50%, 70.00%, 81.25%, and 90.00% with a germination rate of 75.00%, 42.50%, 30.00%, 18.75%, and 10.00%, respectively. The results also showed that infestation of wheat and barley seeds had a greater impact on reducing their germination percentage in unwashed samples compared to washed samples, with significant differences. Unwashed wheat seed samples achieved the highest infestation rate and the lowest germination rate at 81.28% and 18.72%, respectively. Unwashed barley seed samples achieved the highest infestation rate and the lowest germination rate at 74.72% and 25.28%, respectively. It is also noted that the highest infestation rate and the lowest germination rate for wheat and barley seeds were observed in the 100 samples, while the lowest infestation rate and the highest germination rate were found in the 20 samples for both unwashed and washed seeds, respectively. The results indicated that wheat was more preferred by the mite than barley in both unwashed and washed seed samples.

Влияние коротких пептидов на рост и развитие проростков ячменя

The use of peptide preparations is one of the current trends in modern agriculture. These preparations can be used at the stage of seed germination, which is an effective strategy for increasing the dynamics of growth and successful development of plants. The article presents the results of laboratory experiments aimed at studying the effect of a complex of short peptides AC-5 (aspartic acid, glutamic acid, arginine) on the germination of spring barley seeds (Hordeum vulgare L.) - Vladimir variety and the intensity of their germination. The maximum values of germination energy (95%, 71% at the control) and seed germination (99%, 82% at the control) were obtained in variants with seed treatment with a complex of short peptides at concentrations of 1*10-12 and 1*10-13 g/l, the minimum – in variants with seed treatment at concentrations of 1*10-8 g/l. To determine the effective concentration of short peptides that cause the greatest growth-stimulating effect, morphometric characteristics of barley seedlings (length of roots and sprouts, yield of raw biomass, dry mass of sprouts and dry mass of roots) were studied. According to the totality of the maximum values, the optimal concentration of a complex of short peptides for pre–sowing treatment of spring barley seeds of the Vladimir variety is 1*10-13 g/l. Keywords: SPRING BARLEY, A COMPLEX OF SHORT PEPTIDES, SEED GERMINATION, GERMINATION ENERGY, LABORATORY EXPERIENCE

In vitro Seed Germination Studies in Barley Exposed to Zinc Oxide Nanoparticles

Background: Nanotechnology is an emerging field that could lead to novel applications in the fields of biotechnology and agriculture. The present study was conducted to test the efficacy of zinc oxide (ZnO) nanoparticles on the germination of barley seeds. Methods: The current study used a chemical method to prepare ZnO nanoparticles. An absorption band at 322nm using UV/Visible spectroscopy was obtained due to the formation of ZnO nanoparticles. The seeds were given 100, 200, and 500 ppm of ZnO nanoparticles. Seeds in the control group were given distilled water. Zinc was also given as zinc nitrate (0.1M) to the seeds of the zinc- treated group. Results: ZnO nanoparticles at higher concentrations were found to be toxic to plants, whereas their lower concentrations boosted the yield and growth of the plant. The present study showed that ZnO nanoparticles have a significant impact on the seed germination potential and could provide an alternative source for fertiliser or growth enhancers that may improve sustainable agriculture.

Alleviation of Water-Deficit Stress on Seed Germination of Barley and Fenugreek in a Sandy Soil Using Superabsorbent Polymer

Water deficit is one of the major limiting factors of seed crop germination and productivity. Consequently, superabsorbent polymers (SAPs) are among several technologies that enhance water use efficiency, leading to worthy seed germination. The objective of this study was to investigate the potential effect of three rates of SAPs (0.0%, 0.5%, and 1.0% w/w) on the seedling emergence of barley and fenugreek sown in a sandy soil using three replicates in a randomized complete block design. Outdoor pot experiments were conducted in Aswan Province, Egypt. The differences in the final germination percentages (FGPs) were not significant for both seeds, while the application of SAPs enhanced the seedling germination index (GI) with significant differences for both crop seeds. The application of SAP at 0.5% gave the highest GI for barley (2.47 day−1) and fenugreek (2.66 day−1) seeds. The sigmoidal function effectively described the cumulative germination percentage rates for both seeds as a function of time under the SAP levels with R2 greater than 0.992. The maximum rates were 69.4 and 64.6 day−1 for barley and fenugreek seeds at SAP 0.5%, respectively. The corresponding rates for 0.0% SAP were 11 and 12 day−1. The water germination efficiencies (WGE) were 27.76 and 30.04 cm−1 for 0.0% and 0.5% SAP for barley, while they were 23.07 and 29.9 cm−1 for fenugreek. Accordingly, SAPs could represent a promising solution for increasing moisture conservation for seed germination in a sand soil. For strategic management, barley is recommended for growth over fenugreek in a semidried soil.

Bacteria Stenotrophomonas are Promising Agents for the Treatment of Fat-containing Sewage

The results of monitoring the biological properties of indigenous bacterial strains isolated from soils, which for a long time were in contact with highly concentrated wastewater from the slaughterhouse of meat processing units, were presented. The resulting strains are able to grow on slaughterhouse wastewater in the presence of animal fats as a carbon source in concentration exceeding the maximum acceptable level for wastewater intended for biological treatment with activated sludge, it demonstrated combined high growth rates and resistance to chlorides. The stimulating effect of wastewater treated by combined indigenous bacterial strains on the germination of barley and corn seeds was confirmed. These strains were identified as Stenotrophomonas rhizophila.

Allelopathic effect of ragweed (Ambrosia artemisiifolia L.) on seed germination and early seedling growth of barley (Hordeum vulgare L.) and white clover (Trifolium repens L.)

Allelopathy is a unique phenomenon in nature that refers to direct or indirect, positive or negative, impact of one plant (including microorganisms, insects, and herbivores) on another plant through chemical secretions (allelochemicals). Ambrosia artemisiifolia (ragweed) is a well-known invasive plant possessing allelochemicals that have been found to inhibit the growth and development of plants in their immediate environment. This study aimed to determine the allelopathic impact of the aqueous leaf extract isolated from ragweed leaves (concentrated extract, 1:2, 1:4, and 1:8) on seed germination and early seedling growth of barley (Hordeum vulgare L.) and white clover (Trifolium repens L.). The examined aqueous extract of ragweed had a higher inhibitory effect on the germination of white clover seeds compared to barley. The germination of barley seeds was the lowest at the concentrated leaf extract (up to 70%), while the same process in barley seeds was not determined at this concentration. In the other treatments, germination was significantly lower in both examined species compared to the control. Shoot and root growth of both researched species was inhibited in all treatments compared to the control. The obtained results indicate that the aqueous ragweed extract significantly inhibits the growth of roots and shoots of both tested species, which increases the need for more intensive research on this topic.

Effect of MnxOy Nanoparticles Stabilized with Methionine on Germination of Barley Seeds (Hordeum vulgare L.).

The aim of this research was to study the effect of MnxOy nanoparticles stabilized with L-methionine on the morphofunctional characteristics of the barley (Hordeum vulgare L.) crop. MnxOy nanoparticles stabilized with L-methionine were synthesized using potassium permanganate and L-methionine. We established that MnxOy nanoparticles have a diameter of 15 to 30 nm. According to quantum chemical modeling and IR spectroscopy, it is shown that the interaction of MnxOy nanoparticles with L-methionine occurs through the amino group. It is found that MnxOy nanoparticles stabilized with L-methionine have positive effects on the roots and seedling length, as well as the seed germination energy. The effect of MnxOy nanoparticles on Hordeum vulgare L. seeds is nonlinear. At a concentration of 0.05 mg/mL, there was a statistically significant increase in the length of seedlings by 68% compared to the control group. We found that the root lengths of samples treated with MnxOy nanoparticle sols with a concentration of 0.05 mg/mL were 62.8%, 32.7%, and 158.9% higher compared to samples treated with L-methionine, KMnO4, and the control sample, respectively. We have shown that at a concentration of 0.05 mg/mL, the germination energy of seeds increases by 50.0% compared to the control sample, by 10.0% compared to the samples treated with L-methionine, and by 13.8% compared to the samples treated with KMnO4.

The Effect of Polymeric Hydrogel Application on Germination Under Saline Irrigation Water: Case Study of Barley

In recent years, it has been tried to increase the usage areas of polymeric hydrogels, which are used to increase the water holding capacity of light textured soils in agricultural production. In this study, the effects of polymeric hydrogel on the germination of barley seeds under low quality irrigation water conditions were investigated. For this purpose, irrigation water prepared with an Electrical Conductivity (ECi) value of 0 [control], 6, 8, and 12 dS m-1 and Sodium Absorption Rate (SAR) less than 3 is placed in petri dishes in which 0.01 grams hydrogel has been added. 10 seeds of barley (Hordeum vulgare conv. distichon) variety were added to the same petri dishes. According to the results of variance analysis made with the data obtained in the study, it was determined that increasing irrigation water salinity was effective at the 5% significance level on the germination rate and seedling dry weight of barley. However, the difference between the subjects treated with hydrogel was not statistically significant. In response to the increased irrigation water ECi value, the germination rate and germination power of barley decreased. It was determined that hydrogel application did not have any effect on the germination rate and germination power of barley under increasing ECi value conditions.

Nordic microalgae produce biostimulant for the germination of tomato and barley seeds

Microalgal biomass may have biostimulating effects on plants and seeds due to its phytohormonal content, and harnessing this biostimulating effect could contribute to sustainable agriculture. Two Nordic strains of freshwater microalgae species Chlorella vulgaris and Scenedesmus obliquus were each cultivated in a photobioreactor receiving untreated municipal wastewater. The algal biomass and the supernatant after algal cultivation were tested on tomato and barley seeds for biostimulating effects. Intact algal cells, broken cells, or harvest supernatant were applied to the seeds, and germination time, percentage and germination index were evaluated. Seeds treated with C. vulgaris, in particular intact cells or supernatant, had up to 25 percentage units higher germination percentage after 2 days and an overall significantly faster germination time (germinated on average between 0.5 and 1 day sooner) than seeds treated with S. obliquus or the control (water). The germination index was higher in C. vulgaris treatments than in the control for both tomato and barley, and this was observed for both broken and intact cells as well as supernatant. The Nordic strain of C. vulgaris cultivated in municipal wastewater thus shows potential for use as biostimulant in agriculture, adding novel economic and sustainability benefits.

Allelopathic Effects of Cannabis sativa L. Aqueous Leaf Extracts on Seed Germination and Seedling Growth in Durum Wheat and Barley

In this study, the allelochemical-induced effects of the leaf water extract of hemp (Cannabis sativa) on seed germination and seedling growth were investigated in durum wheat (Triticum durum) cv. Mongibello and barley (Hordeum vulgare) cv. Alamo. The seeds were imbibed in 25%, 50%, 75%, or 100% solution concentrations, obtained from a 2% hemp leaf extract, and they were germinated at 20 and 10 °C. The 2% extract stock solution (i.e., 100% solution concentration) was obtained by extracting 20 g of leaf powder in 1 L distilled water (2%, w/v). A control of seeds imbibed in distilled water was considered. Germination was scored daily and at the end of the germination test, the final germination percentage (FGP), mean germination time (MGT), germination index (GI), and vigor index (VI) were calculated. The radicles and shoots of the germinated seeds of both species were also measured for their length and weight. The analyses revealed the presence of phenols in the hemp leaf extract, which were the highest in the 100% concentration (13.14 ± 0.20 mg gallic acid equivalent-GAE g−1 extract). At 20 °C, increasing the concentration had either minor (in wheat) or no effects (in barley) on the seed germination. At 10 °C, the germination was reduced by the increasing concentration, suggesting a potential allelopathic effect of the extract. However, at 100% concentration, the seeds germinated significantly better that those at 75% concentration. At 20 °C, increasing concentration progressively depressed both the radicle and shoot elongation in both species. At 10 °C, the radicle elongation was depressed by the extract, irrespective of the concentration, whilst the shoots were as long as those of the control in wheat, and smaller at the 50 and 75% concentrations in barley. We can conclude that the water extract of hemp leaves can have a negative impact on wheat and barley seed germination and seedling growth, particularly at temperatures below optimal. However, the high concentration of phenols in the extract may stimulate seed germination and seedling growth. Thus, in semi-arid areas, such as those of the Mediterranean regions, sowings of wheat and barley after hemp at an optimal (i.e., 20 °C) or nearly optimal temperature are recommended in order to minimize the combined stressing effects of the temperature and allelopathic leaf extract upon plant establishment, which may limit a successful crop establishment.

Evaluation of Seed Germination of Barley Grown after Priming with Leaf Extract of Moringa and Aqueous Garlic Extract

A pot experiment was designed to determine the effect of seed priming on the germination of barley seeds in the winter season. Seed priming was done by using the leaf extract of Moringa at different concentrations (100%, 50% and 10%v/v) for 24 hours, and aqueous extract of ginger and tap water for different intervals of time (6, 12 and 24 hours). The experiment was continued for ten days with nine seed priming treatments. The results showed that maximum seeds germinated on day nine in all treatments. Whereas the highest germination of seeds was observed when seeds were primed with an aqueous extract of garlic for 24 hours and when seeds were primed with 100% concentration of Moringa leaf extract for 24 hours. The lowest seed germination was observed when seeds were primed with an aqueous extract of garlic for 6 hours. These results showed that Moringa leaf extract and aqueous garlic extract can be used to prime barley seeds to improve germination.

Visualization of Glutamate Decarboxylase Activity in Barley Seeds under Salinity Stress Using Mass Microscope.

γ-Aminobutyric acid (GABA) accumulates in plants in response to environmental stresses. The activity levels of glutamate decarboxylase (GAD), an enzyme involved in GABA biosynthesis, are reported to increase during germination under salinity stress. However, it is not clear which tissues of the plant seeds are affected by GAD activity in response to salinity stress. In this study, the effects of salinity stress on the distribution of barley seeds GAD activity during germination were investigated. The mass spectrometry imaging (MSI) method was optimized, and the distribution of GAD activity in germinated seeds exposed to salinity stress at different germination stages from 12 to 48 h after imbibition was investigated. In this study, MSI was successfully applied to enzyme histochemistry to visualize the relative GAD activity in germinating barley seeds for the first time. The salinity stress increased the GAD activity, mostly due to the increase in relative GAD activity in the embryo. Higher GAD activity was detected in seeds exposed to salinity stress in the scutellum or aleurone layer, which are difficult to separate for extraction. This method can be used to clarify the role of GABA shunts, including GAD enzyme responses, in barley seeds under stress.

Combined Proteomic and Metabolomic Analysis of the Molecular Mechanism Underlying the Response to Salt Stress during Seed Germination in Barley.

Salt stress is a major abiotic stress factor affecting crop production, and understanding of the response mechanisms of seed germination to salt stress can help to improve crop tolerance and yield. The differences in regulatory pathways during germination in different salt-tolerant barley seeds are not clear. Therefore, this study investigated the responses of different salt-tolerant barley seeds during germination to salt stress at the proteomic and metabolic levels. To do so, the proteomics and metabolomics of two barley seeds with different salt tolerances were comprehensively examined. Through comparative proteomic analysis, 778 differentially expressed proteins were identified, of which 335 were upregulated and 443 were downregulated. These proteins, were mainly involved in signal transduction, propanoate metabolism, phenylpropanoid biosynthesis, plant hormones and cell wall stress. In addition, a total of 187 salt-regulated metabolites were identified in this research, which were mainly related to ABC transporters, amino acid metabolism, carbohydrate metabolism and lipid metabolism; 72 were increased and 112 were decreased. Compared with salt-sensitive materials, salt-tolerant materials responded more positively to salt stress at the protein and metabolic levels. Taken together, these results suggest that salt-tolerant germplasm may enhance resilience by repairing intracellular structures, promoting lipid metabolism and increasing osmotic metabolites. These data not only provide new ideas for how seeds respond to salt stress but also provide new directions for studying the molecular mechanisms and the metabolic homeostasis of seeds in the early stages of germination under abiotic stresses.