Growth Of Wheat Seedlings Research Articles

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.

Effects of Light-Emitting Diodes Light Quality on Growth, Development and Metabolism of Wheat (Triticum Aestivum L.) Seedlings

Light quality is considered crucial for plant growth, development and metabolism. The objective of this study was to investigate the impact of different light-emitting diodes (LEDs) light qualities on the growth of wheat (Triticum aestivum L.) seedlings. Five different set of LEDs light quality namely CK, 5R1B, 4R2B1G, 3B3R, 4B2R and 4B2R1G were used. The morphology, stomatal characteristic, biomass accumulation, RubisCO enzyme activity, photosynthetic pigment, value, soluble sugar and protein, Malondialdehyde (MDA ) root activity and others were measured with CK as the control. The results showed that the fresh weight, RubisCO enzyme activity, photosynthetic pigment accumulation, soluble sugar content and stomatal length in 5R1B treatment were higher than other treatment group, which increased by 1, 47, 57 and 18%, respectively compared to CK,. This indicated that 5R1B treatment group is most conducive to plant growth and photosynthesis, and does not cause lipid peroxidation damage to wheat seedlings under light treatment. Bangladesh J. Bot. 51(4): 987-993, 2022 (December) Special

Zinc oxide nanoparticles as potential hallmarks for enhancing drought stress tolerance in wheat seedlings

Drought is one of the major abiotic stresses which negatively affects plant growth and development. The current study evaluated the effects of drought on the growth, physiology, and biochemical attributes of wheat seedlings; and examined the role of foliar application of ZnO nanoparticles in alleviating drought-induced effects. Two wheat cultivars i.e., Anaj-2017 and FSD-2018 were grown in soil-filled pots and were subjected to 100% field capacity (FC) (well watered) and 50% of FC (drought stress). Whilst different treatments of ZnO nanoparticles spray included no spray, water spray, and 50, 100, and 150 ppm ZnO. Results demonstrated that drought caused a significant reduction in seedling fresh and dry weights, photosynthetic pigmentation, and antioxidant activities compared with a well-watered treatment. Nevertheless, the application of 100 and 150 ppm of ZnO nanoparticles effectively ameliorated the negative effects of drought and enhanced the performance of both cultivars under drought. Data revealed a significant increase in fresh and dry weight of shoot and root with the application of ZnO nanoparticles. A substantial increase of 73.68% and 28.51% in chlorophyll “a" and 26.15% and 50.02% in chlorophyll “b" was recorded with the application of 100 ppm of ZnO nanoparticles in Anaj-2017 and FSD-2018, respectively over control (0 ppm). The application of these nanoparticles also triggered the antioxidant defense system and protected the crop from oxidative damage. Averaged across different stress treatments, application of 150 and 100 ppm of ZnO nanoparticles increased the peroxidase activity by 60% and 72% in FSD-2018, and 15% and 23% in Anaj-2017, respectively compared with no spray. FSD-2018 outperformed Anaj-2017 regarding its overall performance under ZnO treatments and drought conditions. In a nutshell, it can be concluded that ZnO nanoparticles ameliorated the negative impacts of drought by improving the growth, physiology, and antioxidant defense of both wheat cultivars.

Study on the Effect of Sodium Nano Lignin Sulfonate on the Growth of Wheat Seedlings under Zinc Stress

Study on the Effect of Sodium Nano Lignin Sulfonate on the Growth of Wheat Seedlings under Zinc Stress

Influence of cultivation technology on the yield of winter wheat

A comprehensive study has been carried out on the influence of technological methods of growing winter wheat on the process of formation of the above-ground mass of plants in the conditions of the forest-steppe of Ukraine. Crop rotation was carried out with two predecessors: black fallow and spring barley at a seeding rate of 3 and 5 million viable seeds/hectare. Evaluation of the intensity of plant development in the initial period of vegetation (measurement of absolutely dry weight of 100 plants 15 and 30 days after the emergence of full seedlings) was recorded in winter wheat plants in black fallow crops. The largest above-ground mass of the plant was formed 30 days after the emergence of full seedlings. A direct correlation was established between the amount of productive moisture in the soil layer of 0-25 cm and the period of emergence of winter wheat seedlings. The highest level of winter wheat yield was obtained for black fallow 3.46 t/ hectare when sown in the second decade of October.

Study on the Effect of Sodium Nano Lignin Sulfonate on the Growth and Development of Wheat Seedlings

Study on the Effect of Sodium Nano Lignin Sulfonate on the Growth and Development of Wheat Seedlings

Comprehensive genomic analysis of Bacillus paralicheniformis strain BP9, pan-genomic and genetic basis of biocontrol mechanism

Many Bacillus species are essential antibacterial agents, but their antibiosis potential still needs to be elucidated to its full extent. Here, we isolated a soil bacterium, BP9, which has significant antibiosis activity against fungal and bacterial pathogens. BP9 improved the growth of wheat seedlings via active colonization and demonstrated effective biofilm and swarming activity. BP9 sequenced genome contains 4282 genes with a mean G-C content of 45.94% of the whole genome. A single copy concatenated 802 core genes of 28 genomes, and their calculated average nucleotide identity (ANI) discriminated the strain BP9 from Bacillus licheniformis and classified it as Bacillus paralicheniformis. Furthermore, a comparative pan-genome analysis of 40 B. paralicheniformis strains suggested that the genetic repertoire of BP9 belongs to open-type genome species. A comparative analysis of a pan-genome dataset using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cluster of Orthologous Gene groups (COG) revealed the diversity of secondary metabolic pathways, where BP9 distinguishes itself by exhibiting a greater prevalence of loci associated with the metabolism and transportation of organic and inorganic substances, carbohydrate and amino acid for effective inhabitation in diverse environments. The primary secondary metabolites and their genes involved in synthesizing bacillibactin, fencing, bacitracin, and lantibiotics were identified as acquired through a recent Horizontal gene transfer (HGT) event, which contributes to a significant part of the strain`s antimicrobial potential. Finally, we report some genes essential for plant-host interaction identified in BP9, which reduce spore germination and virulence of multiple fungal and bacterial species. The effective colonization, diverse predicted metabolic pathways and secondary metabolites (antibiotics) suggest testing the suitability of strain BP9 as a potential bio-preparation in agricultural fields.

Effects of Different Priming Treatments on Germination and Seedling Growth of Wheat under Drought Stress

Wheat (Triticum aestivum L.) is a widely cultivated agricultural crop in dry areas. However, drought is one of the most limiting environmental stress factors for crop production in the world's agricultural areas. Seed priming is a physiological technique involving seed hydration and drying to improve metabolic processes before germination. The aim of this study is to determine the effect of four different priming treatments (hormo-priming (gibberellic acid, GA3), redox-priming (hydrogen peroxide, H2O2), osmo-priming (polyethylene glycol, PEG) and thermo-priming (38oC)) on total chlorophyll content (SPAD), relative water content (RWC), specific leaf area (SLA), H2O2 amounts and shoot-root lengths in a local wheat variety (cv. Ekiz). Drought stress significantly decreased seed germination, shoot-root lengths, SLA, SPAD and RWC while increasing H2O2 content. Thermo-priming treatments fully improved the negative effects of drought on chlorophyll amount and germination compared to control plants. However, shoot-root lengths improved only in half level of control plants. While drought stress decreased seed germination by 14%, hormo-priming treatment ensured germination of all seeds. On the contrary of other priming treatments, hormo-priming and osmo-priming treatments increased RWC. Consequently, thermo-priming and hormo-priming treatments found most effective than the other priming treatments in drought stress resistance for cv. Ekiz.

Seed Priming Improves Biochemical and Physiological Performance of Wheat Seedlings under Low-Temperature Conditions

Wheat is a widely cultivated cereal throughout the world and stress caused by low temperatures significantly affects all stages of wheat development. Seed priming is an effective method to produce stress-resistant plants. This work was carried out to determine whether different priming methods (hormo-, halo-, osmo-, and hydropriming) can increase the resistance of wheat to low-temperature conditions (10 °C). The effect of priming on growth, as well as the biochemical and physiological performance of wheat seedlings were monitored. In general, priming had a significant stimulatory effect on the monitored characteristics. Hormo- and halopriming had a positive effect on the growth, vigor index, and total soluble protein content of wheat seedlings. Additionally, hormopriming reduced the malondialdehyde (MDA) content in wheat seedlings compared to unprimed seeds. A dominant effect on antioxidant enzymes (superoxide-dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and pyrogallol peroxidase) was recorded after seed priming with KNO3. The effectiveness of priming was also confirmed through the increased content of phenolic compounds (including flavonoids), and total antioxidant activity. The HPLC analysis showed increased content of chlorogenic acid, catechin, 4-hydroxy benzoic acid, sinapic acid, rutin, naringin, and quercetin in primed wheat seedlings compared to unprimed grown seedlings under low-temperature conditions with the best effects achieved by hormo- and hydropriming. It is concluded that seed priming can be regarded as a promising approach for increasing the resistance of wheat seedlings to low-temperature stress.

Additive effects of combined heat and salt stress is manifested in an enhanced sodium ions accumulation and increased membrane damage in wheat seedlings

Domestication of wheat (Triticum aestivum L.) in some tropical and subtropical regions may encounter both high temperature and soil salinity problems. This research aims to investigate how salt and heat stress combination affects growth and physiological characteristics of wheat seedlings to unravel their response mechanisms. The 14-d-old wheat seedlings of three cultivars were treated with salt stress (150 mM NaCl), heat stress (42 °C for 4 h) and combined stress (150 mM NaCl at 42 °C for 4 h). Growth and physiological parameters were monitored at 0 h, 24 h, 5 d and 10 d after stress exposure except for ion concentration, which was analyzed at 5 d post stress exposure. The combined stress inhibited shoot growth and compromised physiological parameters (e.g., relative water content [RWC], malondialdehyde [MDA], electrolyte leakage [EL], Na+ content and Na+/K+ ratio) to a greater extent than a single salt or heat stress, demonstrating additive effects particularly on plant water status and membrane stability. After 10 d exposure to the combined stress, the most sensitive cultivar ‘Fahng 60’ exhibited the highest reduction in shoot dry weight (34%). Moreover, ‘Fhang 60’ showed the lowest RWC (36%) and the highest EL (75%) while ‘Samerng 2’ and ‘Phrae 60’ had RWC of 70% and 64%, and EL of 54% and 60%, respectively. The effect was remarkably evidenced after 5 d of stress exposure, suggesting a late onset of stress injury. Together, the results demonstrated that the effect of salt and heat stress combination was additive, which could be manifested in an enhanced Na+ accumulation and membrane damage.

Physio-Biochemical and Transcriptomic Features of Arbuscular Mycorrhizal Fungi Relieving Cadmium Stress in Wheat.

Arbuscular mycorrhizal fungi (AMF) can improve plant cadmium (Cd) tolerance, but the tolerance mechanism in wheat is not fully understood. This study aimed to examine the physiological properties and transcriptome changes in wheat inoculated with or without Glomus mosseae (GM) under Cd stress (0, 5, and 10 mg·kg-1 CdCl2) to understand its role in wheat Cd tolerance. The results showed that the Cd content in shoots decreased while the Cd accumulation in roots increased under AMF symbiosis compared to the non-inoculation group and that AMF significantly promoted the growth of wheat seedlings and reduced Cd-induced oxidative damage. This alleviative effect of AMF on wheat under Cd stress was mainly attributed to the fact that AMF accelerated the ascorbate-glutathione (AsA-GSH) cycle, promoted the production of GSH and metallothionein (MTs), improved the degradation of methylglyoxal (MG), and induced GRSP (glomalin-related soil protein) secretion. Furthermore, a comparative analysis of the transcriptomes of the symbiotic group and the non-symbiotic group revealed multiple differentially expressed genes (DEGs) in the 'metal ion transport', 'glutathione metabolism', 'cysteine and methionine metabolism', and 'plant hormone signal transduction' terms. The expression changes of these DEGs were basically consistent with the changes in physio-biochemical characteristics. Overall, AMF alleviated Cd stress in wheat mainly by promoting immobilization and sequestration of Cd, reducing ROS production and accelerating their scavenging, in which the rapid metabolism of GSH may play an important role.

A Holistic Approach to Utilize Mycorrhizae for Improving Soil Health and Enhancing Yield of Wheat in Bangladesh

Arbuscular mycorrhizal fungi (AMF) species may have positive impacts on wheat productivity through translocation of nutrients within wheat plant tissue. To quantify effect of mycorrhizae species on wheat plant productivity, two experiments were conducted in this study. One preliminary seedlings growth experiment was conducted in sand culture to reckon exact mycorrhizae effect on wheat seedlings growth response and changes in sand properties due to mycorrhizae inoculation. Another pot experiment was conducted to quantify wheat productivity, nutrient content within wheat plant tissue and changes in soil physiochemical characteristics due to four mycorrhizae species amendment. Result showed that wheat seedling responded better due to mycorrhizae inoculation. Mycorrhizae inoculation also improves nutrient content within wheat seedlings tissue and store carbon in sand. Finding also showed that mycorrhizae species inoculation increased growth and yield of wheat as well as phosphorus accumulation within wheat grain. Both experiments showed that mycorrhizae species inoculums store carbon in soil and within wheat plant tissue. J. of Sci. and Tech. Res. 3(1): 01-10, 2021

THE EFFECT OF AQUEOUS EXTRACTS OF ELYTRIGIA REPENS L. ON THE GERMINATION OF WHEAT SEEDS

This article summarizes the results of the study of the allelopathic effect of water-soluble secretions from the rhizomes of creeping wheatgrass on the germination of wheat seeds. In field conditions, the chemical effect of Elytrigia repens L. on the growth of all agricultural crops is characterized as inhibitory. Therefore, the purpose of the article was to establish in laboratory conditions the phytotoxicity of water extracts from the rhizomes of Elytrigia repens L. at various concentrations on the germination of wheat seeds and further development of seedlings. In the course of research, we established that the presence of allelopathically active substances of creeping wheat inhibits the energy of wheat seed germination in all experimental variants. The water extract in a ratio of 1 to 1000 had a stimulating effect on seed germination and further growth of wheat seedlings compared to the control option, in which its seeds were germinated in distilled water. An increase in the concentration of water extracts of creeping wheatgrass (1:100; 1:50; 1:20 and 1:10) directly proportionally led to a significant inhibition of the growth of the germinal root of wheat. The lag of indicators in length ranged from 0.34 cm (1:100) to 1.32 cm (1:10) on the fourth day of accounting. Further measurements of both the length of the germinal root and the total length of the root system of wheat confirmed the prolongation of the negative impact of wheatgrass emissions. The stem length of wheat seedlings also depended on the concentration of allelochemical substances of Elytrigia repens L. in Petri dishes: it decreased with increasing concentration. According to the above options, during the accounting on the 7th day, the decrease in the indicator was from 44.4% (1:100) to 95.9% (1:10) in relation to the control option. That is, the allelopathically active water-soluble substances of Elytrigia repens L. can have a stimulating or inhibiting effect on the germination process of wheat seeds, depending on their concentration level.

Fenclorim Increasing Butachlor Selectivity between Wheat and Roegneria kamoji by Seed Soaking

Roegneria kamoji Ohwi (Poaceae), a wild relative plant of wheat which is widely distributed across China, has become a dominant and problematic weed in wheat fields in some regions. We have previously confirmed that R. kamoji is highly tolerant to foliar-applied acetyl-CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitors in wheat (Triticum aestivum L.). The sensitivity of R. kamoji to pre-emergence (PRE) herbicides and the basis of fenclorim increase selectivity to butachlor between wheat and R. kamoji were evaluated in this study. Screenhouse bioassay showed that R. kamoji exhibited similar sensitivity to wheat to PRE herbicides at their recommended field doses (RFD); it also showed that buatchlor provides the highest relative control for R. kamoji (53.4% emergence and 81.5% fresh weight reduction, respectively), while it had no impact on seedling emergence of wheat among the six PRE herbicides. When butachlor was applied at four-fold RFD, no R. kamoji seedlings emerged; however, it significantly reduced the above-ground biomass of wheat compared with the non-treated control. Pre-treatment with herbicide safener fenclorim by seed soaking increased the ED10 value of butachlor to wheat from 221.8 to 1600.1 g a.i. ha−1, thus increasing the selectivity index from 9.6 to 68.9 between wheat and R. kamoji. The activities of α-amylase activity and protein content during germination, and glutathione-S-transferase (GST) and β-ketoacyl-CoA synthase (KCS) in the seedlings, could be induced by butachlor in both wheat seeds with or without fenclorim pre-soaking. These results suggested that butachlor provides the highest control for R. kamoji and did not affect germination and emergence in wheat. The basis of fenclorim-increased selectivity to butachlor was associated with the induced GST and KCS-mediated enhanced herbicide metabolism in wheat.

Effect of nano-silicon on the regulation of ascorbate-glutathione contents, antioxidant defense system and growth of copper stressed wheat (Triticum aestivum L.) seedlings.

Copper (Cu2+) toxicity can inhibit plant growth and development. It has been shown that silicon (Si) can relieve Cu2+ stress. However, it is unclear how Si-nanoparticles (SiNPs) relieve Cu2+ stress in wheat seedlings. Therefore, the current study was conducted by setting up four treatments: CK, SiNP: (2.5 mM), Cu2+: (500 µM), and SiNP+Cu2+: (2.5 mM SiNP+500 µM Cu2+) to explore whether SiNPs can alleviate Cu2+ toxicity in wheat seedlings. The results showed that Cu2+ stress hampered root and shoot growth and accumulated high Cu2+ concentrations in roots (45.35 mg/kg) and shoots (25.70 mg/kg) of wheat as compared to control treatment. Moreover, Cu2+ treatment inhibited photosynthetic traits and chlorophyll contents as well as disturbed the antioxidant defense system by accumulating malondialdehyde (MDA) and hydrogen peroxidase (H2O2) contents. However, SiNPs treatment increased root length and shoot height by 15.1% and 22%, respectively, under Cu2+ toxicity. Moreover, SiNPs application decreased MDA and H2O2 contents by 31.25% and 19.25%, respectively. SiNPs increased non-enzymatic compounds such as ascorbic acid-glutathione (AsA-GSH) and enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbic peroxidase (APX) activities by 77.5%, 141.7%, 68%, and 80%, respectively. Furthermore, SiNPs decreased Cu2+ concentrations in shoots by 26.2%, as compared to Cu2+ treatment alone. The results concluded that SiNPs could alleviate Cu2+ stress in wheat seedlings. The present investigation may help to increase wheat production in Cu2+ contaminated soils.

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.

Effects of light quality on growth, nutritional characteristics, and antioxidant properties of winter wheat seedlings (Triticum aestivum L.).

Wheat seedlings are becoming popular for its high nutritional value. Effects of White (W), White + Red (WR), and White + Blue (WB) light-emitting diodes (LEDs) treatments on growth, nutritional characteristics and antioxidant properties of wheat seedlings were studied in a plant factory. The results showed that height, leaf area, shoot fresh, and shoot dry weight per wheat seedling were the highest under WR at 13 and 22 days after planting. Soluble sugar content in leaves and stems were 22.3 and 65% respectively higher under WB than those under W. Soluble protein content in leaves and stems were 36.8 and 15.2% respectively lower under WR than those under W. Contents of total flavonoids, glutathione (GSH) and ascorbic acid (ASA) in leaves were the highest under WB, whereas malondialdehyde (MDA) content in leaves was the lowest under WB. The activities of antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX)] in leaves and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability were also the highest under WB. In conclusion, WR promoted the growth of wheat seedlings, and WB promoted antioxidant level and nutritional accumulation. This study provides guidance for wheat seedlings to carry out preferential production (biomass or quality).

Prolonged Use of Insecticide Dimethoate Inhibits Growth and Photosynthetic Activity of Wheat Seedlings: A Study by Laser-Induced Chlorophyll Fluorescence Spectroscopy.

This paper is an extension of the work published in Journal of Fluorescence (2011) 21: 785-791. In the previous work, we studied the effect of dimethoate (50, 100 and 200ppm) on growth and photosynthetic activity of wheat seedlings after 10days of dimethoate treatment. In the present study, new measurement conditions (dimethoate concentration: 25ppm, treatment period: 20days and 30days) were used in addition to those used in the past work. Various plant growth parameters, photosynthetic pigment content, laser-induced chlorophyll fluorescence (LICF) spectra and fluorescence induction kinetics (FIK) curves were recorded after 10, 20 and 30days of dimethoate treatments. LICF spectra were recorded in the region of 650-780nm using violet diode laser (405nm). FIK curves were recorded at 685nm using red diode laser (635nm). Fluorescence intensity ratio (FIR) of two fluorescence peaks around 685 and 730nm, and variable chlorophyll fluorescence decrease ratio (Rfd) were determined from LICF spectra and FIK curves respectively. Curve-fitted parameters of LICF spectra were used for determination of FIR (F685/F730). The effect of treatment of the insecticide dimethoate on growth and photosynthetic activity of wheat seedlings was examined by using these parametersas well as the past work. In 10-days treatment, 25 and 50ppm dimethoate showed stimulatory effect with better stimulation being observed at 25ppm. All studied concentrations higher than 50ppm exhibited inhibitory effect on wheat seedlings. In case of dimethoate treatment studied for longer durations (more than 10days), all concentrations showed inhibitory effect. Lower doses which showed some positive response for short time duration become toxic with the extension of treatment periods. Thus, this study clearly confirms the toxic effect of dimethoate on wheat plants.

The miR164-TaNAC14 module regulates root development and abiotic-stress tolerance in wheat seedlings

Previous studies have revealed the miR164 family and the miR164-targeted NAC transcription factor genes in rice (Oryza sativa) and Arabidopsis that play versatile roles in developmental processes and stress responses. In wheat (Triticum aestivum L.), we found nine genetic loci of tae-miR164 (tae-MIR164 a to i) producing two mature sequences that down-regulate the expression of three newly identified target genes of TaNACs (TaNAC1, TaNAC11, and TaNAC14) by the cleavage of the respective mRNAs. Overexpression of tae-miR164 or one of its target genes (TaNAC14) demonstrated that the miR164-TaNAC14 module greatly affects root growth and development and stress (drought and salinity) tolerance in wheat seedlings, and TaNAC14 promotes root growth and development in wheat seedlings and enhances drought tolerance, while tae-miR164 inhibits root development and reduces drought and salinity tolerance by down-regulating the expression of TaNAC14. These findings identify the miR164-TaNAC14 module as well as other tae-miR164-regulated genes which can serve as new genetic resources for stress-resistance wheat breeding.

Endophytic Fusarium oxysporum GW controlling weed and an effective biostimulant for wheat growth.

Wheat crop has to compete with several weeds including Avena fatua, a noxious weed that alone is responsible for 30–70% losses in the yield annually. Because of the environmental concerns associated with conventional methods, researchers are on a continuous hunt to find clean alternatives in order to manage weeds. Fungi have shown promising weedicide potential in lab studies. The current study aimed to isolate endophytic fungi from wheat plants which can promote wheat growth and inhibit the growth of common weed, A. fatua. Of several isolates, GW (grayish white) was selected for its promising features, and the strain was identified as Fusarium oxisporum through ITS sequencing technique. This fungus released a number of compounds including Isovitexin, Calycosin, quercetagetin, and dihydroxy-dimethoxyisoflavone that inhibited the growth of A. fatua but did not influence the growth of wheat seedlings. Biomass of this fungus in the soil also reduced growth parameters of the weed and promoted the growth of wheat. For instance, the vigor index of A. fatua seedlings was reduced to only 6% of the control by this endophyte. In contrast, endophyte-associated wheat seedlings showed a higher vigor index than the control. Behind this differential response of the two plants were their contrasting physiological and biochemical status. Lower growth phenotypes of A. fatua seedlings had reduced levels of IAA, GAs, and SA and higher the levels of JA and ABA. Besides, their ROS scavenging ability was also compromised as evident from relatively lower activities of catalase, peroxidase, and ascorbic acid oxidase, as well as higher accumulation of ROS in their leaves. Wheat seedlings response to GW was opposite to the A. fatua. It may be concluded that F. oxysporum GW has the ability to differentially modulate physiology and biochemistry of the two hosts leading to contrasting phenotypic responses.