Growth Of Soybean Seedlings Research Articles

Evaluating the impact of Cold plasma on Seedling Growth properties, seed germination, and soybean antioxidant enzyme activity

Cold atmospheric pressure plasma (CAP) has garnered significant attention in recent years for its potential applications in biomedical, environmental, and agricultural fields. Cold plasma treatment exhibits a variety of effects in agricultural applications, including impacts on seed germination and seedling growth; however, further research is required. Soybean serves as a fundamental source of nutrients for both animals and humans. Soybean seeds possess impermeable and thick testae, which results in prolonged germination times and suboptimal germination rates. The soybeans exhibit low uniformity. As a result, poor crop establishment and yield reduction are inevitable outcomes. Therefore, the purpose of this study was to examine the effects of Iranian soybean cultivars, such as Sari, Saba, Arian, Katoul, and Williams, on seedling growth properties, seed germination, and antioxidant enzyme activity, using argon at time intervals of 30, 60, 180, 300, and 420 s. Cold plasma treatment significantly enhanced germination potential from 1.18 to 66.97%, germination index from 0.50 to 60.09%, germination rate from 1.78 to 32.17%, seedling length from 2.70 cm to 78.13 cm, root length from 2.87 cm to 56.13 cm, and seedling dry weight from 1.80 g to 36.63 g. Additionally, CAT activity increased from 0.88- to 4.40-fold, SOD activity from 0.86- to 5.89-fold, and APX activities from 0.40- to 4.01-fold compared to the control treatment. The findings indicated that the samples exhibited optimal results at treatment durations of 60 and 180 s. The influence of plasma on the antioxidant responses of seedlings, seed germination, and growth characteristics was contingent upon the duration of treatment. Cold plasma, when applied for an appropriate duration, may enhance soybean seedling growth characteristics and seed germination.

Impact of Sulfur Deficiency and Excess on the Growth and Development of Soybean Seedlings.

Sulfur is a critical element for plant growth and development, serving as a component of amino acids (cysteine and methionine), iron-sulfur clusters, proteins, glutathione, coenzymes, and auxin precursors. Deficiency or low concentrations of sulfur in the soil can lead to significant growth retardation in plants. The objective of our study was to examine the effects of sulfur (S) deficiency and excess on morphological symptoms, sulfur and nitrogen (N) metabolism, as well as antioxidant activity in soybean. We found that S starvation decreased the fine root length, biomass, and activity, and the chlorophyll content was reduced, while excess sulfur promotes lateral root growth. In contrast to sulfur excess, sulfur deficiency inhibits N and S metabolism levels in both subsurface and above-ground parts, and induced the expression of some sulfur transporters (SULTRs). In this study, we created soybean hairy root lines overexpressing the SULTR gene (GmSULTR2;1a) to observe metabolic changes following sulfur deficiency treatment. The results showed that GmSULTR2;1a saved the sulfur-deficient phenotype, and the antioxidant enzyme activity was much higher than that of the wildtype in the absence of sulfur. Our study revealed the important role of sulfur element in soybean growth and development and the regulation of sulfur deficiency by GmSULTR2;1a.

Oceanobacillus picturae alleviates cadmium stress and promotes growth in soybean seedlings

Cadmium (Cd) is a heavy metal that significantly impacts human health and the environment. Microorganisms play a crucial role in reducing heavy metal stress in plants; however, the mechanisms by which microorganisms enhance plant tolerance to Cd stress and the interplay between plants and microorganisms under such stress remain unclear. In this study, Oceanobacillus picturae (O. picturae) was isolated for interaction with soybean seedlings under Cd stress. Results indicated that Cd treatment alone markedly inhibited soybean seedling growth. Conversely, inoculation with O. picturae significantly improved growth indices such as plant height, root length, and fresh weight, while also promoting recovery in soil physiological indicators and pH. Metabolomic and transcriptomic analyses identified 157 genes related to aspartic acid, cysteine, and flavonoid biosynthesis pathways. Sixty-three microbial species were significantly associated with metabolites in these pathways, including pathogenic, adversity-resistant, and bioconductive bacteria. This research experimentally demonstrates, for the first time, the growth-promoting effect of the O. picturae strain on soybean seedlings under non-stress conditions. It also highlights its role in enhancing root growth and reducing Cd accumulation in the roots under Cd stress. Additionally, through the utilization of untargeted metabolomics, metagenomics, and transcriptomics for a multi-omics analysis, we investigated the impact of O. picturae on the soil microbiome and its correlation with differential gene expression in plants. This innovative approach unveils the molecular mechanisms underlying O. picturae's promotion of root growth and adaptation to Cd stress.

Gamma-aminobutyric acid (GABA) improves salinity stress tolerance in soybean seedlings by modulating their mineral nutrition, osmolyte contents, and ascorbate-glutathione cycle

BackgroundIn plants, GABA plays a critical role in regulating salinity stress tolerance. However, the response of soybean seedlings (Glycine max L.) to exogenous gamma-aminobutyric acid (GABA) under saline stress conditions has not been fully elucidated.ResultsThis study investigated the effects of exogenous GABA (2 mM) on plant biomass and the physiological mechanism through which soybean plants are affected by saline stress conditions (0, 40, and 80 mM of NaCl and Na2SO4 at a 1:1 molar ratio). We noticed that increased salinity stress negatively impacted the growth and metabolism of soybean seedlings, compared to control. The root-stem-leaf biomass (27- and 33%, 20- and 58%, and 25- and 59% under 40- and 80 mM stress, respectively]) and the concentration of chlorophyll a and chlorophyll b significantly decreased. Moreover, the carotenoid content increased significantly (by 35%) following treatment with 40 mM stress. The results exhibited significant increase in the concentration of hydrogen peroxide (H2O2), malondialdehyde (MDA), dehydroascorbic acid (DHA) oxidized glutathione (GSSG), Na+, and Cl− under 40- and 80 mM stress levels, respectively. However, the concentration of mineral nutrients, soluble proteins, and soluble sugars reduced significantly under both salinity stress levels. In contrast, the proline and glycine betaine concentrations increased compared with those in the control group. Moreover, the enzymatic activities of ascorbate peroxidase, monodehydroascorbate reductase, glutathione reductase, and glutathione peroxidase decreased significantly, while those of superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase increased following saline stress, indicating the overall sensitivity of the ascorbate-glutathione cycle (AsA-GSH). However, exogenous GABA decreased Na+, Cl−, H2O2, and MDA concentration but enhanced photosynthetic pigments, mineral nutrients (K+, K+/Na+ ratio, Zn2+, Fe2+, Mg2+, and Ca2+); osmolytes (proline, glycine betaine, soluble sugar, and soluble protein); enzymatic antioxidant activities; and AsA-GSH pools, thus reducing salinity-associated stress damage and resulting in improved growth and biomass. The positive impact of exogenously applied GABA on soybean plants could be attributed to its ability to improve their physiological stress response mechanisms and reduce harmful substances.ConclusionApplying GABA to soybean plants could be an effective strategy for mitigating salinity stress. In the future, molecular studies may contribute to a better understanding of the mechanisms by which GABA regulates salt tolerance in soybeans.

Enhanced degradation of atrazine from soil with recyclable magnetic carbon-based bacterial pellets: Performance and mechanism

Herein, magnetic biochar coupled with Acinetobacter lwoffii DNS32 immobilized pellets (DMBC-P) were synthesized through sodium alginate embedding and fixation, which could fast and completely eliminate atrazine from contaminated farmland soil. Characterization results revealed that DMBC-P exhibited a significant abundance of three-dimensional network porous structures, thereby enhancing the stability and specific surface area of DMBC-P. The application of 0.5 % DMBC-P could completely remove 22 mg/kg atrazine from soil within 4 d under the condition of moisture content of 60 % and soil pH of 7.4. After 5 d of remediation, DMBC-P could be easily extracted from the soil by magnetic separation and still had 100 % removal efficiency for atrazine after 3 rounds of recycling. Moreover, DMBC-P effectively alleviated the oxidative damage of atrazine to soybean seedlings through significantly decreasing the activities of various plants antioxidant enzymes by 27 % to 79 %. Meanwhile, analysis of 16S rRNA revealed a significant increase in the relative abundance of functional microflora such as Acidobacteriota and Chloroflexi at the phylum level, which promoted the growth of soybean seedlings. Additionally, pore filling, hydrogen bonding, and π-π stacking were identified as the primary mechanisms responsible for atrazine adsorption onto DMBC-P. Subsequently, the degrading bacteria DNS32 immobilized on DMBC-P was employed to catalyze the decomposition of atrazine into non-toxic cyanuric acid based on LC-MS. Overall, this study provided a reasonable design of magnetic carbon-based bacterial pellet for atrazine-contaminated soil remediation, which could efficiently remove atrazine and be effectively recycled after remediation.

Effects of Mepiquat Chloride on Physiology of Soybean under Drought Stress

Background: Drought is an important factor restricting the development of agriculture. In recent years, plant growth regulators have achieved more results in improving crop stress resistance. The physiological mechanism of exogenous application of mepiquat chloride on soybean seedlings has undergone significant changes under drought stress. Methods: In order to study the effect of exogenous chlorine on the physiology of soybean under drought stress., ‘Heinong 65’ was used as the experimental material, 15% PEG-6000 was used to simulate drought stress and different concentrations of mepiquat chloride solution (100, 300, 500, 700 mg/L) were sprayed at the three-leaf stage of soybean growth by pot method. The dry matter accumulation, auxin (IAA), zeatin (ZA), gibberellin (GA3), abscisic acid (ABA) content and superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX) activity of soybean were determined. Result: The results showed that the activities of antioxidant enzymes SOD, POD, CAT and APX in soybean leaves under drought stress were significantly increased by the treatment of appropriate concentration of mepiquat chloride solution. IAA, GA3 and ZA endogenous hormone levels increased, dry matter accumulation increased, root-shoot ratio and ABA endogenous hormone levels decreased significantly. It can be seen that mepiquat chloride treatment can improve the antioxidant capacity, promote the growth of soybean seedlings under drought stress and effectively alleviate the inhibition of drought stress on soybean growth and development.

Co-inoculation of Soybean Seedling with Trichoderma asperellum and Irpex laceratus Promotes the Absorption of Nitrogen and Phosphorus.

Soybean are one of the main oil crops in the world. The study demonstrated that co-inoculation with Trichoderma asperellum(Sordariomycetes, Hypocreomycetidae) and Irpex laceratus (Basidiomycota, Polyporales) isolated from Kosteletzkya virginica can promote the growth of soybean seedlings. The two fungi were found to produce various enzymes, including cellulase, amylase, laccase, protease, and urease. Upon inoculation, T. asperellum mainly colonized within the phloem of the roots in soybean seedlings, while I. laceratus mainly in the xylem and phloem of the roots. Physiological parameters, such as plant height, root length, and fresh weight, were significantly increased in soybean seedlings co-inoculated with T. asperellum and I. laceratus. Moreover, the expression of key genes related to N and P absorption and metabolism was also increased, leading to improved N and P utilization efficiency in soybean seedlings. These results indicate that the two fungi may have complementary roles in promoting plant growth, co-inoculation with T. asperellum and I. laceratus can enhance the growth and nutrient uptake of soybean. These findings suggest that T. asperellum and I. laceratus have the potential to be used as bio-fertilizers to improve soybean growth and yield.

Interação de plântulas de soja com rizobactérias benéficas

Beneficial rhizobacteria are multifunctional microorganisms that stimulate plant growth through direct mechanisms such as the solubilization of phosphorus and potassium present in soil minerals, biological nitrogen fixation and production of plant hormones. The objective of this study was to determine the effect of beneficial rhizobacteria on the initial development, promoting growth and resistance of soybean seedlings, aiming not only for increased production but also for agricultural sustainability through the maximization of biological efficiency in the early development of soybean seedlings. The experiment, under controlled conditions, was conducted in a completely randomized design, with four treatments and ten replications. The treatments consisted in the microbiolization of soybean seeds with: 1. Control (without microorganism); 2. Serratia marcenses (BRM 32114); 3. Bacillus spp. (BRM63573) and 4. BRM 32114 + (BRM63573). After the microbiolization of the seeds, they were sown and placed to germinate, after 12 days, the seedlings were harvested and divided into shoots and roots. The roots were washed and photographed with digital camera. The images were analyzed and determined length, diameter, surface area and volume of roots. Then, root and shoot were dried and weighed for biomass determination. Co-inculation, BRM 32114+ BRM63573, promoted greater robustness of the root system of soybean seedlings with increased length (16.2%), diameter (22.5%), volume (43.4%) and dry biomass (29.7%). The dry matter of shoots and total soybean seedlings was superior to the control treatment in all treatments with rhizobacteria. Therefore, plant growth promoting

Interaction of Seedling-Pathogens with Physiological Seed Quality Affecting Soybean Emergence and Seedling Growth

Interaction of Seedling-Pathogens with Physiological Seed Quality Affecting Soybean Emergence and Seedling Growth

ИЗУЧЕНИЕ ВЛИЯНИЯ ЭНДОФИТНЫХ БАКТЕРИЙ РОДА BACILLUS НА РОСТ И СТРЕССОУСТОЙЧОВОСТЬ ПРОРОСТКОВ ЯРОВОЙ ПШЕНИЦЫ И СОИ

The studies were carried out to assess the indicators of seed germination, root length, level of lipid peroxidation, content of photosynthetic pigments and free proline in monocotyledonous and dicotyledonous crops when seeds were treated with strains of endophytic bacteria of the genus Bacillus. The scheme of vegetation experiments included modeling of 30% drought on sand and pre-sowing treatment of seeds of spring wheat variety Yoldyz and soybean variety Sultana with endophytic bacteria: Bacillus subtilis KS-55 AU, Bacillus cereus KS-56 AU, Bacillus pumilus KS-57 AU, Bacillus megaterium KS- 58 AU, Bacillus cereus KS-59 AU, Bacillus megaterium KS-60 AU and Bacillus pumilus KS-61 AU. Bacteria better stimulated root growth when using a titer of 1×106 cells in 1 ml of the drug (the increase was 0.6 cm on soybean with Bacillus subtilis KS-55 AU and Bacillus megaterium KS-60 AU and 0.4 cm on wheat with Bacillus cereus KS -56 AU, Bacillus cereus KS-59 AU and Bacillus pumilus KS-61 AU). In wheat, the Bacillus subtilis KS-55 AU strain stood out, treatment with which contributed to an increase in germination by 30%, a decrease in the level of lipid peroxidation by 46%, an increase in the amount of free proline by 148% and photosynthetic pigments by 6%, relative to the control variant. On soybean plants, the strain Bacillus subtilis KS-55 AU contributed to an increase in germination by 40%, Bacillus cereus KS-59 AU contributed to a decrease in the level of lipid peroxidation by 47% and the accumulation of proline by 73%, and Bacillus pumilus KS-61 AU increased the amount of total chlorophyll by 141%, relative to the control variant. Thus, we can conclude that the above strains of endophytic bacteria improve the growth and development of spring wheat and soybean seedlings, and also serve as inducers of crop resistance to soil drought.

Identification of bioactive compounds of Bacillus velezensis HNA3 that contribute to its dual effects as plant growth promoter and biocontrol against post-harvested fungi.

Bacillus velezensis HNA3 displayed dual bioactivities as a plant growth promoter and a biocontrol agent against five isolated post-harvest phytopathogens: Alternaria alternata, Cladosporium cladosporioides, Penicillium expansum, Monilinia fructicola, and Fusarium oxysporum. Moreover, the volatile organic compounds (VOCs) emitted by HNA3 exhibited remarkable efficacy, achieving 100% fungal inhibition against Alternaria alternata and Cladosporium cladosporioides. This is the initial study to demonstrate the HNA3-emitted VOCs effect on enhancing soybean seedling growth and seed germination by breaking seed dormancy and improving root construction. Semi-VOCs and emitted VOCs were identified by two methods of extraction coupled with gas chromatography-mass spectrometry. A total of 14 main VOCs were detected; phenol,2,4-bis(1,1-dimethylethyl) and 1,2-benzenedicarboxylic acid are the most abundant semi-VOCs, both are known to have anti-fungal and plant growth-promoting properties. 9-Octadecenoic acid (z)-, methyl ester is the most common volatile compound emitted by HNA3 followed by hexadecanoic acid, methyl ester and heptadecanoic acid, methyl ester. It is noteworthy that heptadecanoic acid, methyl ester has not been previously detected in Bacillus spp. Pure 9-octadecenoic acid (z)-, methyl ester, as well as heptadecanoic acid, methyl ester, exhibited inhibitory effects on the fungal growth of all isolated phytopathogens. Interestingly, when combined, these compounds synergistically eradicated fungal growth. Indole acetic acid and serotonin, both classified as plant growth-promoting indoles, have been identified within HNA3. Moreover, during the phytopathogen inhibition stage, HNA3 demonstrated upregulation in gene expression associated with non-VOCs, including bacillibactin, bacillomycin, bacilysin, and surfactin. This study publicized an extensive variety of bioactive compounds produced by HNA3 liable for its bioactivities.IMPORTANCEThe current study is an extension to our previous work on the plant growth-promoting rhizobacteria (PGPR) Bacillus velezensis HNA3 strain, which comes to confirm and reveals the huge stock of active secondary metabolites produced by HNA3. HNA3-emitted volatile organic compounds (VOCs) have demonstrated the capacity to impede the growth of phytopathogens affecting some fruits and vegetables, even in the absence of direct contact. Additionally, these volatiles enhanced soybean seed germination by breaking seed dormancy and inducing root system development. Furthermore, they promoted seedling growth, giving it prominence in soybean cultivation. The relevance of active volatiles derives from the fact that they can be developed as natural-safe biocontrol agents and plant promoters. This research validates the remarkable bioactivities exhibited by the Bacillus velezensis HNA3 and their potential applications in agriculture as an inoculant, encompassing biocontrol, plant growth promotion, and seed germination activities, thereby offering a safer alternative to hazardous chemicals.

Effect of Plasma-Activated Water (PAW) Generated With Various N2/O2 Mixtures on Soybean Seed Germination and Seedling Growth

Effect of Plasma-Activated Water (PAW) Generated With Various N₂/O₂ Mixtures on Soybean Seed Germination and Seedling Growth

Cadmium affects the growth, antioxidant capacity, chlorophyll content, and homeostasis of essential elements in soybean plants

Soybean (Glycine max L.), as an oil and protein crop, has attracted interest for its potential in the reclamation/restoration of barren and contaminated habitats due to its ability to tolerate adverse environments. To investigate the effects of the growth (biomass and plant height), chlorophyll content, antioxidative capacity (peroxidase and superoxide dismutase activities), and homeostasis of essential elements in soybean plants induced by cadmium (Cd), a pot experiment was performed. Soybean seeds were cultivated in six different levels of Cd-contaminated soil (0, 0.25, 0.50, 1.00, 2.50, 5.00, and 10.00 mg kg−1) for 27 days at 60 % humidity and 25–35 °C in a greenhouse with natural light. Soybean seedling growth was stimulated and inhibited at low (≤1.00 mg kg−1) and high (≥2.50 mg kg−1) Cd concentrations, respectively. Essential metal elements (Mg, Fe, and Zn) and chlorophyll contents of leaves were increased and decreased at low and high Cd concentrations, respectively. Exposure to high Cd concentrations interfered with the homeostasis of essential elements in soybean plants. High Cd concentrations reduced antioxidant capacity and chlorophyll content, which inhibited soybean growth. The Cd accumulation level (>100 mg kg−1) in soybean plant organs was unsafe for producing soybean products. However, soybean seedlings appear to tolerate moderate Cd contamination.

Agricultural tillage practice and rhizosphere selection interactively drive the improvement of soybean plant biomass.

Rhizosphere microbes play key roles in plant growth and productivity in agricultural systems. One of the critical issues is revealing the interaction of agricultural management (M) and rhizosphere selection effects (R) on soil microbial communities, root exudates and plant productivity. Through a field management experiment, we found that bacteria were more sensitive to the M × R interaction effect than fungi, and the positive effect of rhizosphere bacterial diversity on plant biomass existed in the bacterial three two-tillage system. In addition, inoculation experiments demonstrated that the nitrogen cycle-related isolate Stenotrophomonas could promote plant growth and alter the activities of extracellular enzymes N-acetyl- d-glucosaminidase and leucine aminopeptidase in rhizosphere soil. Microbe-metabolites network analysis revealed that hubnodes Burkholderia-Caballeronia-Paraburkholderia and Pseudomonas were recruited by specific root metabolites under the M × R interaction effect, and the inoculation of 10 rhizosphere-matched isolates further proved that these microbes could promote the growth of soybean seedlings. Kyoto Encyclopaedia of Genes and Genomes pathway analysis indicated that the growth-promoting mechanisms of these beneficial genera were closely related to metabolic pathways such as amino acid metabolism, melatonin biosynthesis, aerobactin biosynthesis and so on. This study provides field observation and experimental evidence to reveal the close relationship between beneficial rhizosphere microbes and plant productivity under the M × R interaction effect.

An Ensemble Learning Model for Detecting Soybean Seedling Emergence in UAV Imagery.

Efficient detection and evaluation of soybean seedling emergence is an important measure for making field management decisions. However, there are many indicators related to emergence, and using multiple models to detect them separately makes data processing too slow to aid timely field management. In this study, we aimed to integrate several deep learning and image processing methods to build a model to evaluate multiple soybean seedling emergence information. An unmanned aerial vehicle (UAV) was used to acquire soybean seedling RGB images at emergence (VE), cotyledon (VC), and first node (V1) stages. The number of soybean seedlings that emerged was obtained by the seedling emergence detection module, and image datasets were constructed using the seedling automatic cutting module. The improved AlexNet was used as the backbone network of the growth stage discrimination module. The above modules were combined to calculate the emergence proportion in each stage and determine soybean seedlings emergence uniformity. The results show that the seedling emergence detection module was able to identify the number of soybean seedlings with an average accuracy of 99.92%, a R2 of 0.9784, a RMSE of 6.07, and a MAE of 5.60. The improved AlexNet was more lightweight, training time was reduced, the average accuracy was 99.07%, and the average loss was 0.0355. The model was validated in the field, and the error between predicted and real emergence proportions was up to 0.0775 and down to 0.0060. It provides an effective ensemble learning model for the detection and evaluation of soybean seedling emergence, which can provide a theoretical basis for making decisions on soybean field management and precision operations and has the potential to evaluate other crops emergence information.

Effect of nitrogen application levels on photosynthetic nitrogen distribution and use efficiency in soybean seedling leaves

BackgroundNitrogen nutrition is strongly associated with crop growth and development. Nitrogen application level affects leaf size as well as nitrogen content and distribution, and thus affects photosynthetic nitrogen-use efficiency (PNUE) and yield. In this study, soybean varieties “Jinyuan 55” and “Keshan 1” were treated with nitrogen as urea at: N0, 0 kg hm−2; N0.5, 60 kg hm−2; N1, 120 kg hm−2; and N1.5, 180 kg hm−2. We compared the effect of nitrogen level on plant morphology, biomass, photosynthetic physiology, nitrogen distribution, PNUE, and other soybean seedling leaf characteristics. ResultsMaximum carboxylation and electron transfer, net photosynthetic rates, and PNUE of both soybean varieties showed initial significant increases with increasing nitrogen application rate and subsequent stabilization. PNUE, carboxylation system components, electron transport components, and non-photosynthetic system distribution ratios in the photosynthetic system increased and subsequently decreased with increased nitrogen application rate. The nitrogen ratio between carboxylation and electron transport systems was positively correlated with PNUE in both soybean varieties. The nitrogen ratio in light-harvesting and non-photosynthetic systems showed a linear negative correlation with PNUE. ConclusionsOverall, an appropriate nitrogen level maintained a high photosynthetic nitrogen ratio, whereas low- or high-nitrogen conditions increased or decreased the nitrogen ratio in non-photosynthetic and photosynthetic systems, respectively, thus decreasing the PNUE and photosynthetic capacity. Moreover, increased nitrogen application rate led to a decreased nitrogen ratio in the light-harvesting system and an increased nitrogen ratio of electron transport and carboxylation systems. Our results provide a theoretical basis for optimizing leaf nitrogen distribution, determining optimum nitrogen levels, and promoting soybean seedling growth.

Evaluation of a high‐speed planter in soybean production

AbstractTimely and quality planting of soybean is important to achieve maximum yield potential. Wet spring soil conditions and rain frequently shorten the time for farmers to plant crops within optimal soil conditions. New planter technology has been introduced that enables farmers to plant their fields faster and more precisely than with traditional planters. Large plot field studies were conducted in Indiana from 2015 to 2017 to evaluate a high‐speed planter at various planting speeds with multiple seeding rates on soybean. Seedling emergence, plant distribution, and final yield were evaluated. Three planting speeds [8, 12, and 16 kilometers per hour (kph)] and two seeding rates (222,000 and 321,000 seeds ha−1) were included in all years, and an additional planting speed and seeding rate were included in 2016 (20 kph and 420,000 seeds ha−1, respectively). Overall, planting speed did not impact soybean seedling emergence. Uniformity of plant spacing decreased slightly as the planting speed increased from 8 to 20 kph in 2016. Cool and wet conditions immediately after planting likely led to inconsistent emergence. Final grain yield was not affected by planting speeds or seeding rate except in 2017 when 12 kph planting speed yielded 0.25 Mg ha−1 higher than the other planting speeds. Increasing planting speed can be achieved without detrimentally affecting plant population, plant spacing, and yield in soybean.

Chemical composition and initial growth of soybean seedlings under flooding conditionat R5 growth stage

This work aimed to evaluate the chemical composition and the initial growth of soybean seedlings originated from seeds produced under influence of soil flooding in the crop reproductive period. The experimental design was totally randomized, organized in factorial scheme being two soybean cultivars x three soil-flooding periods, and the traits were disposed in four repetitions. When submitting soybean plants to flooding at R5 stage, the mass of thousand seeds was reduced independently of the cultivar. The shoot growth and length, shoot dry matter, and roots dry matter characters were negatively influenced due to soil flooding in R5 growth stage. The oxygen deficiency can cause alteration in roots and shoot protein concentration on soybeans seedlings. The aminoacids concentration was stimulated in roots and shoot of seedlings originated from seeds produced under hypoxia conditions.

3-Hydroxy-3-methylglutaryl coenzyme A reductase genes from Glycine max regulate plant growth and isoprenoid biosynthesis

Isoprenoids, a large kind of plant natural products, are synthesized by the mevalonate (MVA) pathway in the cytoplasm and the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway in plastids. As one of the rate-limiting enzymes in the MVA pathway of soybean (Glycine max), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is encoded by eight isogenes (GmHMGR1–GmHMGR8). To begin, we used lovastatin (LOV), a specific inhibitor of GmHMGR, to investigate their role in soybean development. To further investigate, we overexpressed the GmHMGR4 and GmHMGR6 genes in Arabidopsis thaliana. The growth of soybean seedlings, especially the development of lateral roots, was inhibited after LOV treatment, accompanied by a decrease in sterols content and GmHMGR gene expression. After the overexpression of GmHMGR4 and GmHMGR6 in A. thaliana, the primary root length was higher than the wild type, and total sterol and squalene contents were significantly increased. In addition, we detected a significant increase in the product tocopherol from the MEP pathway. These results further support the fact that GmHMGR1–GmHMGR8 play a key role in soybean development and isoprenoid biosynthesis.

Evaluating the initial growth of soybean (Glycine max) seedlings in response to different concentrations of copper compounds in the maternal plant

Evaluating the initial growth of soybean (Glycine max) seedlings in response to different concentrations of copper compounds in the maternal plant