Growth Of Wheat Plants Research Articles

Assessment of nitrogen-fixing endophytic and mineral solubilizing rhizospheric bacteria as multifunctional microbial consortium for growth promotion of wheat and wild wheat relative Aegilops kotschyi

Microbes play crucial functions in maintaining the health and growth of the plants directly or indirectly by supplying nutrients. These microbes could be used as biofertilizers for the enhancement of soil health and growth of crops. In preset investigation, potential microbes from endophytic and rhizospheric region of Aegilops kotschyi growing in green slopes of Shivaliks, Himachal Pradesh were sorted out and screened for plant growth promoting attributes including phosphorus and potassium solubilization. The potential bacterial strains were identified through 16S rRNA gene sequencing and developed as microbial consortium for the plant growth of wheat and wild wheat relative Aegilops kotschyi. A total 125 isolates of bacteria were sorted out and among them 36 were found as P-solubilizers and 19 showed K-solubilization attribute and two highly potential bacterial strain were identified as Bacillus tropicus EU-ARP-44 (P-solubilizer; 270.5 ± 0.00 mg L−1) and B. megaterium EU-ARK-23 (K-Solubilizer; 51.3 ± 1.7 mg mL−1). The microbial consortium of Rahnella sp. strain EU-A3SNfb (N-fixer; MN294545), B. tropicus EU-ARP-44 (P-solubilizer) and B. megaterium EU-ARK-23 (K-solubilizer) evaluation in Aegilops kotschyi and wheat crop resulted in the enhancement of growth as well as physiological parameter including shoot/root length, fresh/dry weight and chlorophyll, carotenoid, total soluble sugar content, phenolic and flavonoid content as compared to un-inoculated control. Microbial consortium consisting of potential plant growth promoting (PGP) bacterial strains could be used as biofertilizer and bioinoculants in cereals crop growing in hilly region.

The Physiological Responses of Wheat and Maize Seedlings Grown under Water Deficit Are Modulated by Pre-Application of Auxin-Type Plant Growth Regulators.

The physiological responses of wheat and maize seedlings to exogenous auxin-type compounds 1-[2-chloroethoxycarbonyl-methyl]-4-naphthalenesulfonic acid calcium salt (TA-12) and 1-[2-dimethylaminoethoxicarbonylmethyl]naphthalene chlormethylate (TA-14) application prior to polyethyleneglycol-6000 (PEG) treatment were studied. PEG treatment inhibited seedlings growth and caused alterations in their antioxidant defence which was crop-specific. PEG increased the non-enzymatic antioxidants along with inhibition of enzymatic antioxidant activity in wheat, while in maize the opposite effects were found. The TA-12 and TA-14 applied alone increased most of the growth parameters measured in both crops, as well as the catalase activity and protein content of wheat. The growth of PEG-treated wheat and maize plants was improved by foliar spray with TA-compounds (TAs). Application of TAs before PEG treatment maintained low-molecular weight thiol-containing compounds and protein contents, and catalase and peroxidase activities close to the control levels. This was better expressed in maize than in wheat seedlings. The results showed that the preliminary application of TA-12 and TA-14 can reduce the adverse effects of moderate water deficit by crop-specific adjustment of the antioxidant defence to counteract stress.

TO THE QUESTION OF THE EFFECTS OF SHUNGHITES ON PLANT GROWTH AND DEVELOPMENT

The effects of shungite rocks (ShR) from Turastamozero (1, 5, 25, 100%), Nigozero (1, 5, 10, 25, 100%) and Zazhogino (1, 5, 100%) deposits added to growing substrate on wheat ( Triticum aestivum L.) and barley ( Hordeum vulgare L.) plant growth and development were studied. Silica sand was used as a control substrate for plant growing.Plants were grown in growth chambers at a temperature of 23°C or 15°C, PAR 200 µmol m -2 s -1 and irrigated with a complete or 25% nutrient solution. Salt stress was provided by irrigation with 1,68% NaCl solution for 3 days. Periodic drought conditions were simulated by watering plants every 2-3 days.The results of the experiments have shown that plant growth and development is affected not only by the concentration of ShR in the substrate, but also the type (deposit location) of the ShR. There was recorded positive effect of TurastamozeroShR at 1 and 25% concentrations on the photosynthetic activity and accumulation od plant biomass. ShR from Nigozero deposit at concentrations above 5% inhibited plant growth and development due to high acidity of the substrate. The effects of ZazhoginoShR on these processes at 1 and 5% concentrations were insignificant. The use of ShR as 100% substrate have shown that only ShR from Turastamozero deposit is suitable for plant growing. In the substrates containing 100% ShR from Nigozero and Zazhogino the seeds did not germinate.Under mineral nutrition deficiency, wheat plants in the substate with 1 and 5% TurastamozeroShRhad larger biomass compared to control plants. Under periodic drought stress, the use of 1 and 5% ShR from all three deposits led to an increase of root biomass of barley, however, plant biomass was higher than the control only when 1% TurastamozeroShR was used. No positive effect of ShR on plant tolerance to salt and chilling stress was found. Based on our own results and literature data, we analyzed the hypothetical reasons of direct and indirect effects of ShR on plant growth and development. It is concluded that the practical use of ShR requires great care and further study, since without understanding the mechanisms of their effects on plants it is impossible to ensure their effective use in order to control growth, development and productivity. It is also obvious that the general term “shungite” is not Applicable in plant physiology and crop science as ShR from different deposits and mixed with other substrates in the fertilizing compositions can have very different, even opposing effects on plants.

Evaluation of inorganic phosphate solubilizing efficiency and multiple plant growth promoting properties of endophytic bacteria isolated from root nodules Erythrina brucei

BackgroundIn soils, phosphorous (P) mostly exists in fixed/insoluble form and unavailable for plants use in soil solution, hence it is in scarcity. P is fixed in the form of aluminium, iron and manganese phosphates in acidic soils and calcium phosphate in alkaline soils. Phosphate solubilizing bacteria, the ecological engineers play a pivotal role in the mobilization of fixed forms of P by using different mechanisms. The objectives of this study were to evaluate inorganic phosphate solubilizing efficiency and other multiple plant growth promoting traits of Erythrina brucei root nodule endophytic bacteria and to investigate effects of the selected endophytic bacteria on the growth of wheat plant under phosphorous deficient sand culture at greenhouse conditions.ResultsAmong a total of 304 passenger endophytic bacteria, 119 (39%) exhibited tricalcium phosphate (TCP) solubilization; however, none of them were formed clear halos on solid medium supplemented with aluminum phosphate (Al-P) or iron phosphate (Fe–P). Among 119 isolates, 40% exhibited IAA production. The selected nine potential isolates also exhibited potentials of IAA, HCN, NH3 and/or hydrolytic enzymes production. All the selected isolates were potential solubilizers of the three inorganic phosphates (Al-P, Fe–P and TCP) included in liquid medium. The highest values of solubilized TCP were recorded by isolates AU4 and RG6 (A. soli), 108.96 mg L−1 and 107.48 mg L−1, respectively at sampling day3 and 120.36 mg L−1 and 112.82 mg L−1, respectively at day 6. The highest values of solubilized Al-P and Fe–P were recorded by isolate RG6, 102.14 mg L−1 and 96.07 mg L−1, respectively at sampling days 3 and 6, respectively. The highest IAA, 313.61 µg mL−1 was recorded by isolate DM17 (Bacillus thuringiensis). Inoculation of wheat with AU4, RG6 and RG5 (Acinetobacter soli) increased shoot length by 11, 17.4 and 14.6%, respectively compared to the negative control. Similarly, 76.9, 69.2 and 53.8% increment in shoot dry weight is recorded by inoculation with RG6, AU4 and RG5, respectively. These nine potential endophytic isolates are identified to Gluconobacter cerinus (4), Acinetobacter soli (3), Achromobacter xylosoxidans (1) and Bacillus thuringiensis (1).ConclusionAU4, RG6 and RG5 can be potential bio-inoculants candidates as low cost agricultural inputs in acidic and/or alkaline soils for sustainable crop production.

Effect of applying bio-enriched rock phosphate on soil properties and wheat plant growth

Effect of applying bio-enriched rock phosphate on soil properties and wheat plant growth

Zinc- and magnesium-doped hydroxyapatite-urea nanohybrids enhance wheat growth and nitrogen uptake

The ongoing and unrestrained application of nitrogen fertilizer to agricultural lands has been directly linked to climate change and reductions in biodiversity. The agricultural sector needs a technological upgrade to adopt sustainable methods for maintaining high yield. We report synthesis of zinc and magnesium doped and undoped hydroxyapatite nanoparticles, and their urea nanohybrids, to sustainably deliver nitrogen to wheat. The urea nanohybrids loaded with up to 42% nitrogen were used as a new source of nitrogen and compared with a conventional urea-based fertilizer for efficient and sufficient nitrogen delivery to pot-grown wheat. Doping with zinc and magnesium manipulated the hydroxyapatite crystallinity for smaller size and higher nitrogen loading capacity. Interestingly, 50% and 25% doses of urea nanohybrids significantly boosted the wheat growth and yield compared with 100% doses of urea fertilizer. In addition, the nutritional elements uptake and grain protein and phospholipid levels were significantly enhanced in wheat treated with nanohybrids. These results demonstrate the potential of the multi-nutrient complexes, the zinc and magnesium doped and undoped hydroxyapatite-urea nanoparticles, as nitrogen delivery agents that reduce nitrogen inputs by at least 50% while maintaining wheat plant growth and nitrogen uptake to the same level as full-dose urea treatments.

Photosynthetic performance and nutrient uptake under salt stress: Differential responses of wheat plants to contrasting phosphorus forms and rates.

Salt stress impacts phosphorus (P) bioavailability, mobility, and its uptake by plants. Since P is involved in many key processes in plants, salinity and P deficiency could significantly cause serious damage to photosynthesis, the most essential physiological process for the growth and development of all green plants. Different approaches have been proposed and adopted to minimize the harmful effects of their combined effect. Optimising phosphorus nutrition seems to bring positive results to improve photosynthetic efficiency and nutrient uptake. The present work posed the question if soluble fertilizers allow wheat plants to counter the adverse effect of salt stress. A pot experiment was performed using a Moroccan cultivar of durum wheat: Karim. This study focused on different growth and physiological responses of wheat plants grown under the combined effect of salinity and P-availability. Two Orthophosphates (Ortho-A & Ortho-B) and one polyphosphate (Poly-B) were applied at different P levels (0, 30 and 45 ppm). Plant growth was analysed on some physiological parameters (stomatal conductance (SC), chlorophyll content index (CCI), chlorophyll a fluorescence, shoot and root biomass, and mineral uptake). Fertilized wheat plants showed a significant increase in photosynthetic performance and nutrient uptake. Compared to salt-stressed and unfertilized plants (C+), CCI increased by 93%, 81% and 71% at 30 ppm of P in plants fertilized by Poly-B, Ortho-B and Ortho-A, respectively. The highest significant SC was obtained at 45 ppm using Ortho-B fertilizer with an increase of 232% followed by 217% and 157% for both Poly-B and Ortho-A, respectively. The Photosynthetic performance index (PItot) was also increased by 128.5%, 90.2% and 38.8% for Ortho-B, Ortho-A and Poly B, respectively. In addition, Poly-B showed a significant enhancement in roots and shoots biomass (49.4% and 156.8%, respectively) compared to C+. Fertilized and salt-stressed plants absorbed more phosphorus. The P content significantly increased mainly at 45 ppm of P. Positive correlations were found between phosphorus uptake, biomass, and photosynthetic yield. The increased photochemical activity could be due to a significant enhancement in light energy absorbed by the enhanced Chl antenna. The positive effect of adequate P fertilization under salt stress was therefore evident in durum wheat plants.

Effect of Compost Tea, Cyanobacterial Strains and their Extracts on Growth and Productivity of Wheat Plant

Effect of Compost Tea, Cyanobacterial Strains and their Extracts on Growth and Productivity of Wheat Plant

Self-assembled degradable iron-doped mesoporous silica nanoparticles for the smart delivery of prochloraz to improve plant protection and reduce environmental impact

Herein, a degradable silicon-based iron-doped nanoparticle (Fe-MSN) was prepared as a porous carrier. After loading the pesticide prochloraz (Pro), tannic acid (TA) was used to seal the pores and stabilize the nanocarrier structure. Due to the enough pore surface areas, the loading rate of Pro@Fe-MSNs/TA nanoparticles (Nps) was up to 31%. Nps possessed an excellent acid-responsive controlled-release of Pro and degradation behavior of the silica wall. Nanocarrier could effectively protect Pro against photodegradation and improve the storage stability of Pro. Pesticide deposition was enhanced by good wettability and Nps possessed better inhibitory efficacy against Rhizoctonia solani. The biosafety of Nps was evaluated and showed no obvious toxicological influence on cells and zebrafish. Furthermore, the pot experiment showed that nanocarriers could effectively promote the growth of wheat plants due to the rich supply of metal trace element. This study provides a promising strategy for sustainable crop disease management to reduce environmental risk. • Nanoparticles possessed an excellent acid-responsive controlled-release of prochloraz and degradation behavior of the silica wall. • The loading rate of nanoparticle was up to 31%. • Nanocarriers improved the stability and wettability of prochloraz. • Nanoparticles possessed better inhibitory efficacy against Rhizoctonia solani . • Iron-doped nanocarriers could effectively promote the growth of wheat plants.

Bioremediation of crude oil and its effect of residue in growth of wheat plants

Three strains of bacteria were studied to bioremediation crude oil in soil and in the laboratory. These bacteria were Azospirillum spp., Azotobacter spp. And Rhizobium spp. The results showed that Azospirillum spp. , Rhizobium spp. was more efficiency to bioremediation crude oil than Azotobacter spp., also the results showed that the higher number of bacteria was recorded in soil treatment with Rhizobium spp. in presence of crude oil in first week , and the number of this bacteria reached to 22.6 x 108 , but the lowest number of bacteria was recorded in soil without added crude oil (control), and the number reached to 2 x 107.The statistical methods obtained that no significant were recorded between different treatments . Also, the results showed that the numbers of bacteria in soil treatment with crude oil were decreased regularly from second week until ten weeks. The results showed that the height of the aerial parts of wheat plants reached to 73 cm in soil treatment with Azotobacter spp. And crude oil after 10 weeks, and the lower length reached to 47 cm. At the same time the results obtained that the higher wet weight of wheat plants was reached to 56 gm in soil treatment with Rhizobium spp., and in the presence of crude oil after 10 weeks, but the lower wet weight was reached to 25 gm in control. Also, the results showed that the higher of dry weight of wheat plants was reached to 23 gm in soil treatment with Rhizobium spp. and in the presence of crude oil after 10 weeks, but the lower dry weight was reached to 10 gm in control, however the statistical methods that no significant were recorded between the different treatments. Also, that all these bacteria have ability to removal crude oil in soil and in mineral salts medium.

Bioremediation of crude oil and its effect of residue in growth of wheat plants

Bioremediation of crude oil and its effect of residue in growth of wheat plants

The influence of biological preparations Azofix and Maxprolin and nitrogen fertilisation on soil mineral nitrogen content in growing season and after spring wheat harvest

The objective of the research reported here was to determine the effect of Azofix and Maxprolin against nitrogen fertiliser on mineral nitrogen content in the soil during the period of intensive growth of spring wheat plants and after its harvest. The following two factors were chosen: I. Biological products: control, Azofix, Maxprolin, Azofix + Maxprolin; II. Nitrogen fertilisation: non-fertilised control, 60 kg N ha–1, 90 kg N ha–1, 90 kg N ha–1 + foliar fertilisation. During the period of intensive growth of spring wheat plants and after harvesting, mineral nitrogen content in the soil was determined. The research demonstrated that, during the period of their intensive growth, spring wheat plants had access to the largest amount of mineral nitrogen in the topsoil following treatment with Azofix + Maxprolin and an application of the nitrogen rate of 90 kg N ha–1.

Effects of Rhizobium leguminosarum Thy2 on the Growth and Tolerance to Cadmium Stress of Wheat Plants.

Cadmium (Cd) stress is an obstacle for crop production, quality crops, and sustainable agriculture. An important role is played by the application of eco-friendly approaches to improve plant growth and stress tolerance. In the current study, a pre-sowing seed treatment with Rhizobium leguminosarum strains, isolated from the leguminous plants Phaseolus vulgaris (strain Pvu5), Vicia sylvatica (strain VSy12), Trifolium hybridium (strain Thy2), and T. pratense (strain TPr4), demonstrated different effects on wheat (Triticum aestivum L.) plant growth under normal conditions. Among all tested strains, Thy2 significantly increased seed germination, seedling length, fresh and dry biomass, and leaf chlorophyll (Chl) content. Further analysis showed that Thy2 was capable of producing indole-3-acetic acid and siderophores and fixing nitrogen. Under Cd stress, Thy2 reduced the negative effect of Cd on wheat growth and photosynthesis and had a protective effect on the antioxidant system. This was expressed in the additional accumulation of glutathione and proline and the activation of glutathione reductase. In addition, Thy2 led to a significant reduction in oxidative stress, which was evidenced by the data on the stabilization of the ascorbate content and the activity of ascorbate peroxidase. In addition, Thy2 markedly reduced Cd-induced membrane lipid peroxidation and electrolyte leakage in the plants. Thus, the findings demonstrated the ability of the R. leguminosarum strain Thy2, isolated from T. hybridium nodules, to exert a growth-promoting and anti-stress effect on wheat plants. These results suggest that the Thy2 strain may enhance wheat plant growth by mitigating Cd stress, particularly through improving photosynthesis and antioxidant capacity and reducing the severity of oxidative damage. This may provide a basic and biological approach to use the Thy2 strain as a promising, eco-friendly candidate to combat Cd stress in wheat production.

Role of Antioxidant Enzymes and Glutathione S-Transferase in Bromoxynil Herbicide Stress Tolerance in Wheat Plants.

Background: Numerous pesticides and herbicides used in excess cause oxidative stress in plants. These chemicals protect plants from weeds and pests, but they also have very negative side effects, making them common abiotic stressors. One of the most significant nutritional crops in the world is the wheat plant. Conditions of herbicide stress have a negative impact on the plant’s phonological phases and metabolic pathways. Plants primarily make an effort to adjust to the environment and develop oxidative homeostasis, which supports stress tolerance. Methods: When controlling broadleaf weeds that emerge after cereal crop plants have been planted, bromoxynil is frequently used as a selective-contact herbicide. This study looked at the effects of the cyanobacteria Arthrospira platensis and Nostoc muscorum aqueous extracts, tryptophan, and bromoxynil (Bh) alone or in combination on wheat plant growth parameters. Both tryptophan and cyanobacterial extract were used as chemical and natural safeners against Bh application. The antioxidant activity and transcriptome studies using qRT-PCR were assayed after 24, 48, 72, 96 h, and 15 days from Bh application in the vegetation stage of wheat plants (55 days old). Results: In comparison with plants treated with Bh, wheat plants treated with cyanobacteria and tryptophan showed improvements in all growth parameters. Following application of Bh, wheat plants showed reduced glutathione content, as well as reduced antioxidant enzyme activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-s-transferase. The combination of different treatments and Bh caused alleviation of the harmful effect induced by Bh on the measured parameters. Additionally, the expression of glutathione synthase and glutathione peroxidase, in addition to those of three genes (Zeta, Tau, and Lambda) of the GST gene family, was significantly upregulated when using Bh alone or in combination with different treatments, particularly after 24 h of treatment. Conclusion: The current study suggests using cyanobacterial extracts, particularly the A. platensis extract, for the development of an antioxidant defense system against herbicide toxicity, which would improve the metabolic response of developed wheat plants.

Influence of Aged Wood Biochar on Mycorrhizal Colonisation, Growth and Leaf Gas Exchange of Wheat and Clover with Different Water Regimes

Water scarcity is one of the most limiting environmental factors for crop productivity globally, where biochar application can play a role. To test this, a glasshouse experiment was conducted with aged biochar application with water regimes on arbuscular mycorrhizal fungi colonisation, plant growth, phosphorus nutrition and leaf gas exchange in wheat and subterranean clover. Six treatment combinations (two biochar levels of 0 and 6 t ha−1; and three water regimes of well-watered, water-stressed and watering intermittently) were arranged in factorial completely randomized block design with three replications. The wheat and subterranean clover were grown and harvested 14, 24, 34 and 44 days after sowing. In this study, aged biochar had no significant effect on plant growth for both wheat and clover, regardless of water regimes. Shoot and root dry weights increased in well-watered conditions compared to water-stressed conditions. Root length and colonised root length increased with biochar addition for wheat, mostly in well-watered treatment. Phosphorus uptake increased in biochar treatment, and the effect was higher in well-watered conditions. Leaf photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci) and transpiration rate (E) increased with biochar addition. For clover, the effect was higher in water-stressed than well-watered conditions. These results suggest that biochar may enhance water availability to clover plants in water-stressed conditions. However, the positive effect of biochar on plant growth under water-stressed conditions, varied with plant species, needs to be explored further in a range of crop species and biochar sources in addition to the material used in the current investigation.

Enhancement of Seed Germination, Growth, Yield, and Nutritional Composition Using Low-Frequency Glow Discharge (LFGD) Plasma in Wheat (Triticum Aestivum)

Several factors affect germination and seedling growth for the successful establishment of crops. This study investigates the effect of medium pressure (~10 torr) low-frequency glow discharge (LFGD) (Ar+Air) plasma-treated seeds for different periods (1, 3, 6, 8, and 10 min) of wheat. The scanning electron microscopy (SEM) image of the seed surface showed notable changes due to plasma treatment. The germination results showed a significant increase of 4.35%, and the agronomical parameters exhibited a meaningful upgrade result in treated plants compared to control. The catalase (CAT) and superoxide dismutase (SOD) activities significantly improved in shoot and root of plants along with their expression candidate genes (TaCAT and TaSOD) in roots relative to control. Besides, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity substantially increased in shoots of plants. A dissimilarity effect was observed in ascorbate peroxidase (APX) and the candidate gene for Ta APX. Further, hydrogen peroxide (H2O2), soluble protein, and sugar content showed significant changes in the leaves and roots but not in nitric oxide (NO) due to plasma treatment. In addition, thousand grain mass (TGM) and nutritional compositions including iron grain, iron shoot, manganese grain, fat, fiber, and ash were significantly increased in contrast to controls. Also, zinc concentration showed no changes in plants, while the moisture content showed significant decreases. Thus, these findings unveil the potentialities of LFGD plasma to improve the germination and growth of wheat plants.

Morphology and Nitrogen Uptake and Distribution of Wheat Plants as Influenced by Applying Remedial Urea Prior to or Post Low-Temperature Stress at Seedling Stage

Wheat production is dramatically influenced by temperature. Low-temperature stress that frequently occurs seriously hampers the growth and development of wheat seedlings. In order to alleviate the damage of low temperature to wheat plant growth, remedial nitrogen was applied prior to or post low-temperature stress at seedling stage using controlled-temperature incubators to explore the difference in wheat morphology and nitrogen absorption and utilization efficiency. Nitrogen amendment significantly increased the leaf area, seedling height, tiller number and dry matter weight of wheat plants as compared with the treatment without nitrogen amendment under temperature stress. Remedial nitrogen applied prior to low-temperature stress (N-LT) was more conducive to increase the above parameters than that applied post low-temperature stress (LT-N). In addition, N-LT enhanced the ability of roots to absorb remedial 15N urea, promoted the growth and development of wheat plants under low-temperature stress, resulting in higher leaf SPAD readings, more new tillers, as well as increased dry weight of roots and above-ground organs. This study suggested that remedial nitrogen should be applied prior to low-temperature stress because it is more effective in restoring the growth of wheat plants under low-temperature stress.

Wheat straw- and maize straw-derived biochar effects on the soil cadmium fractions and bioaccumulation in the wheat–maize rotation system

Wheat–maize rotation is one of the most popular systems and successful intensification cropping systems in Northern China, while soils in some of this area are contaminated by cadmium (Cd). However, few studies have performed experiments on the reduction of Cd accumulation in the wheat–maize rotation system. In this study, wheat- and maize-derived biochars are applied to the Cd-contaminated soil to reduce the Cd accumulation in the wheat and maize plants. The results showed that soil biochar applications can significantly decrease DTPA-extracted Cd concentrations by 12.7–26.0% and 13.1–20.5% by wheat- and maize-derived biochars, respectively. Sequential extractions showed that biochar applications significantly reduced the Cd mobility and bioavailability in soils and changed the exchangeable and carbonate-bound fractions of Cd to organic material-bound and residual fractions. The biochar applications increased the plant growth, yield, and quality of both wheat and maize, especially a significant increase in high dosages. The biochar applications also improved the antioxidant enzyme activities and reduced the reduction of MDA in both wheat and maize roots. The Cd concentrations in wheat grains were reduced by 38.1–91.5% and 65.9–80%, and maize grain Cd concentrations were reduced by 20.9–54.2% and 30.8–44% by wheat- and maize-derived biochar applications, respectively, and the Cd concentrations in the root, stem, and leaf were also significantly reduced. The wheat-derived biochar was more effective on the Cd reduction in soil bioavailable fractions and Cd accumulation in crop plants.

Bacillus halotolerans KKD1 induces physiological, metabolic and molecular reprogramming in wheat under saline condition

Salt stress decreases plant growth and is a major threat to crop yields worldwide. The present study aimed to alleviate salt stress in plants by inoculation with halophilic plant growth-promoting rhizobacteria (PGPR) isolated from an extreme environment in the Qinghai–Tibetan Plateau. Wheat plants inoculated with Bacillus halotolerans KKD1 showed increased seedling morphological parameters and physiological indexes. The expression of wheat genes directly involved in plant growth was upregulated in the presence of KKD1, as shown by real-time quantitative PCR (RT-qPCR) analysis. The metabolism of phytohormones, such as 6-benzylaminopurine and gibberellic acid were also enhanced. Mining of the KKD1 genome corroborated its potential plant growth promotion (PGP) and biocontrol properties. Moreover, KKD1 was able to support plant growth under salt stress by inducing a stress response in wheat by modulating phytohormone levels, regulating lipid peroxidation, accumulating betaine, and excluding Na+. In addition, KKD1 positively affected the soil nitrogen content, soil phosphorus content and soil pH. Our findings indicated that KKD1 is a promising candidate for encouraging wheat plant growth under saline conditions.

Identification and Validation of the Genomic Regions for Waterlogging Tolerance at Germination Stage in Wheat

Waterlogging occurs when field soil is saturated with water induced by extensive rainfall or improper irrigation, which is a severe abiotic stress influencing wheat plant growth and yield production. At the germination stage, waterlogging usually induces rot of seeds and reduced germination rate and seedling survival. Development of tolerant wheat varieties is the most efficient approach to improve seed germination and mitigate the damages caused by waterlogging. In this study, we screened 432 wheat accessions at germination stage by waterlogging treatment, and identified 27 tolerant accessions with a germination rate of over 80% after treatment. To identify quantitative trait loci (QTL) for waterlogging tolerance, two segregation populations were developed by crossing waterlogging-tolerant cultivars Shannong 135 and Huaimai 18 with sensitive cultivars Siyang 936 and CD1840, respectively. Three QTL qWlg5A, qWlg7B and qWlg2D for waterlogging tolerance were detected on chromosomes 5A, 7B and 2D through bulked segregation analysis genotyped by wheat 55K SNP array. Two, one, and two kompetitive allele specific PCR (KASP) assays linked with qWlg5A, qWlg7B and qWlg2D were developed and validated in the two populations, respectively. The identified waterlogging tolerant germplasm lines, the QTL for waterlogging tolerance and the high-throughput KASP markers, were highly valuable in improving waterlogging tolerance in wheat-marker-assisted breeding.