Search Results (769)

Sugarcane productivity varies widely among genotypes, but the biochemical traits underlying these differences remain poorly characterized. In this study, six contrasting sugarcane cultivars were profiled to investigate how ionomic, hormonal, flavonoid, and photosynthetic pigment signatures are associated with yield and sucrose accumulation. Morphological traits and field performance revealed marked genotypic variation, with ZZ14 and GL1215 achieving the highest yields and sugar content, while GT59 and GT60 performed less favorably. Multivariate analyses of ionomic data showed that potassium, magnesium, and calcium were consistently enriched in high-yield cultivars, whereas sodium, boron, and manganese were negatively associated with growth traits. Hormone profiling revealed that high-yielding genotypes utilize diverse strategies: while the high-yielding GL1215 achieved superior sugar content with the lowest levels of growth-promoting hormones, the LT1790 genotype, despite having the highest levels of these hormones, showed suboptimal yield due to a costly trade-off with its hyperactive defense system. Flavonoid analysis indicated that LT1790 contained the highest levels of Quercetin, rutin, and caffeic acid, suggesting enhanced antioxidant capacity, whereas GT59 preferentially accumulated chlorogenic acid. Canonical correlation analysis confirmed that nutrient balance and metabolite composition strongly correlated with plant height, stem diameter, and sugar concentration. Together, these results suggest that high-yield sugarcane genotypes achieve a superior metabolic balance, combining efficient nutrient uptake and robust antioxidant capacity with a favorable hormone profile that promotes strong growth without triggering a costly constitutive defense system. Full article

Olive mill wastewater is a polluting residue generated from the olive oil industry and is one which constitutes an environmental concern in Mediterranean countries. Composting has been reported as a viable valorization alternative, as it reduces the volume and the phytotoxic characteristics of OMW. In this study, several composts derived from OMW were evaluated under controlled conditions over two growing season pot experiments using Lactuca sativa as a test crop. The analysis focused on soil quality changes, crop yield, and plant development. Additionally, potential phytotoxicity was also evaluated through a direct acute toxicity plant growth test. Application of OMW composts improved soil fertility indicators, including oxidizable carbon, Kjeldahl total nitrogen, Olsen phosphorous, and plant availability. Crop yields were comparable to those obtained with other organic amendments such as vermicompost and fresh cattle manure in both growing seasons and plant development (in terms of chlorophyll content and canopy cover) was not negatively affected. Nutrient uptake (NPK) was consistent during both growing seasons, with similar nitrogen use efficiency to that achieved in other organic treatments. Regarding the potential toxic effect, the OMW composts tested enhanced seed germination when mixed with coconut fiber at weight ratios below 29.2%. No half-maximal effective concentration (EC50) values were detected, even at 100% compost concentration, while half-maximal inhibitory concentration (LC50) values ranged between 65–75%. These results indicate that OMW composts can serve as an effective short-term source of plant-available nitrogen and a medium-term source of phosphorus, without risk of finding inhibitory or phytotoxic effects on crops. Full article

Recently, we reported the efficacy of organic nutrient solutions in supporting the hydroponic cultivation of Diplotaxis muralis. The aim of this study was to elucidate the influence of standard and enhanced vermitea formulations, compared to the conventional Hoagland solution, on phytochemical and metabolomic changes in D. muralis. Using NMR-based metabolomics and multivariate analysis, we observed significant metabolite variation among treatments. Both vermitea formulations increased the levels of acetate, alanine, and 2-oxoglutarate, and boosted the biosynthesis of key secondary metabolites, including methoxy flavonoids and glucosinolates. The standard vermitea treatment further resulted in a higher accumulation of leucine and citrate, while the Hoagland solution induced higher glucose concentrations. Enhanced vermitea improved copper and zinc uptake, positively correlating with methoxy flavonoid production. In contrast, the higher phosphorus and potassium content of the Hoagland solution correlated with increased glucose levels in D. muralis. Metabolite profiling coupled with multivariate analysis identified the enhanced vermitea as the best alternative to chemical nutrient solution for improving the nutritional and phytochemical quality of D. muralis leaves. Full article

Soil salinity disrupts rhizosphere interactions, impairing root–microbe symbioses, nutrient uptake, and water relations in onion (Allium cepa L.) and garlic (Allium sativum L.). This study evaluated the efficacy of biofertilizers (Azotobacter chroococcum SARS 10 and Azospirillum lipoferum SP2) and organic amendments (sewage sludge and poultry manure) in salt-affected soils in Kafr El-Sheikh, Egypt. Five treatments were applied: (T1) control (no amendments); (T2) biofertilizer (3 L/ha for onion, 12 L/ha for garlic) + inorganic P (150 kg/ha P₂O₅ for onion, 180 kg/ha for garlic) and K (115 kg/ha K₂SO₄ for onion, 150 kg/ha for garlic); (T3) 50% inorganic N (160 kg/ha for onion, 127.5 kg/ha for garlic) + 50% organic manure (6000 kg/ha for onion, 8438 kg/ha for garlic) + P and K; (T4) biofertilizer + T3; and (T5) conventional inorganic NPK (320 kg/ha N for onion, 255 kg/ha N for garlic + P and K). Soil nutrients (N, P, K), microbial biomass carbon (MBC), dehydrogenase activity, and microbial populations were analyzed using standard protocols. Plant growth (chlorophyll, photosynthetic rate), stress indicators (malondialdehyde, proline), and yield (bulb diameter, fresh yield) were measured. Treatment T4 increased MBC by 30–40%, dehydrogenase activity by 25–35%, available N (39.7 mg/kg for onion, 35.7 mg/kg for garlic), P (17.9 mg/kg for onion), and K (108 mg/kg for garlic). Soil organic matter rose by 8–12%, and cation exchange capacity by 26–36%. Chlorophyll content improved by 25%, malondialdehyde decreased by 20–30%, and fresh yields increased by 20–30% (12.17 tons/ha for garlic). A soybean bioassay confirmed sustained fertility with 20–25% higher dry weight and 30% greater N uptake in T4 plots. These findings highlight biofertilizers and organic amendments as sustainable solutions for Allium productivity in saline rhizospheres. Full article

The diversification of cover crops grown in soils with granulometric variability may potentially enhance microbial community and enzyme activities. Thus, the main goal was to evaluate the effect of autumn/winter cover crop sequences and cash crops in spring/summer on soil microbial biomass and enzyme activities. The experiment was conducted in open-field microplots (10 m × 1 m × 0.7 m), containing soils from B horizon of five Oxisols with granulometric variability and clay content ranging from 17 to 80 dag kg⁻¹. The treatments were three cover crops and a winter fallow with a completely randomized experimental design with three replicates. Soil samples from the 0–10 cm layer were collected to analyze soil microbial biomass of carbon and nitrogen, enzyme activities of the acid phosphatase, arylsulfatase, urease, and fluorescein diacetate hydrolysis. The number of nodules in soybean roots was average 63 ± 14.42 nodules per plant and dry mass of nodules was 169 ± 13.74 mg plant⁻¹. Soybean nodulation and N uptake ensured the supply of nitrogen to the soybean plants with 331 ± 82 mg plant⁻¹. Overall, diversified autumn/winter cover crop sequences provide plant residue, containing nutrients, and different carbon/nitrogen, which alters microbial biomass, the ratio of C_mic/N_mic, basal respiration, and soil enzyme activities within each Oxisol with different particle size distribution. Full article

Excess sodium in soil disrupts ionic balance and limits water uptake, negatively affecting growth and stolon production in strawberry plants. This study assessed the effects of chitosan (CTS), brassinosteroids (BRs), and thidiazuron (TDZ) on stolon performance and physiological responses of strawberry cv. ‘Portola’ under saline conditions. A greenhouse experiment included seven treatments: CTS, BRs, CTS + BRs combinations, TDZ, and an untreated control. Foliar applications were used to evaluate impacts on nutrient uptake, photosynthetic pigments, oxidative stress, and stolon production. BRs alone [2.53 × 10⁻⁶ μM] significantly increased crown diameter (+43%), stolon number (+65%), stolon length (+4%), and daughter plant formation (+8%), while reducing leaf sodium by 60% and improving Mg²⁺/Na⁺ and K⁺/Na⁺ ratios. The CTS + BRs combination enhanced phenolic content and produced the heaviest first daughter plants (6.1 g). TDZ, however, resulted in weaker stolons, lower chlorophyll a content, and reduced K⁺/Na⁺ ratios, suggesting a need for dose optimization. Overall, BRs, alone or with CTS, improved salt tolerance and stolon propagation through enhanced ion regulation, photosynthesis, and antioxidant defenses. These findings advance understanding of how biostimulants modulate metal ion homeostasis, antioxidant signaling, and growth in salt-sensitive crops, offering strategies to mitigate salinity stress in strawberry cultivation. Full article

Azotobacter vinelandii OP is a bacterium that can produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HBV), a biodegradable and biocompatible polymer with applications in the biomedical field. This study aimed to evaluate P3HBV production and its 3-hydroxyvalerate (3HV) fraction under different agitation rates and oxygen uptake rates (q_O2) in chemostat cultures of A. vinelandii OP. Steady-state conditions with either oxygen or carbon limitation were established by modulating the agitation rates. Under oxygen-limited conditions (low q_O2 values) biomass and P3HBV concentrations increased to 3.3 g L⁻¹ and 2.1 g L⁻¹, respectively. At higher q_O2 values, the chemostat cultures were limited by carbon, and P3HBV content decreased from 62% to 33% (w w⁻¹). The highest 3HV molar fractions, 33.7 and 36.4 mol %, were observed at both the lowest and highest q_O2 levels, possibly linked to comparable valeric acid consumption rates. An elevated NAD(P)H/NAD(P)⁺ ratio was also observed under oxygen limitation, favoring polymer accumulation by indicating a more favorable intracellular redox state. These findings highlight the impact of nutrient limitation and respiratory activity on the biosynthesis of P3HBV and the 3HV composition by Azotobacter vinelandii OP. Such insights can support the development of tailored bioprocesses to modulate polymer characteristics, enabling a broader range of potential biomedical applications for P3HBV. Full article

Oryza sativa L. is the largest food crop in the world. The harmful filamentous green algae Spirogyra in paddy fields poses a serious threat to O. sativa yield. Therefore, biological control for Spirogyra is important for sustainable agricultural development. The native fish species Acrossocheilus yunnanensis can graze on Spirogyra and exhibits strong environmental adaptability, providing a novel approach to the biological control of Spirogyra. Therefore, we designed the O. sativa+Spirogyra+A. yunnanensis co-culture system to study the effects of A. yunnanensis on O. sativa growth and physiological characteristics. The results indicated that Spirogyra stress significantly inhibited O. sativa biomass accumulation, root length and plant height development, reduced photosynthetic efficiency, and increased the contents of oxidative stress markers including malondialdehyde (MDA) and hydrogen peroxide (H₂O₂). Interestingly, grazing of A. yunnanensis on Spirogyra increased the biomass of Oryza sativa by 58.60%, the root–shoot ratio by 78.01%, and the root length and plant height by 49.83% and 25.85%, respectively. Meanwhile, the soil nitrate nitrogen (NO₃⁻-N), ammonium nitrogen (NH₄⁺-N), and available phosphorus (AP) were enhanced, which improved O. sativa nutrient uptake and promoted photosynthetic pigment accumulation. This was manifested by an increase in chlorophyll content, net photosynthetic (Pn), transpiration rate, stomatal conductance (Gs), and intercellular CO₂ concentration (Ci). Grazing of A. yunnanensis on Spirogyra alleviated the oxidative damage to O. sativa induced by Spirogyra, as evidenced by decreased malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) level in both leaves and roots, along with increased protein content. This provides a new strategy for constructing a rice–fish symbiotic system by using indigenous fish species, achieving Spirogyra control and sustainable agricultural development. Full article

Global food security is challenged by population growth and the environmental toll of conventional fertilizers. Enhancing biological nitrogen fixation (BNF) in legumes like soybean (Glycine max) is a sustainable fertilization alternative. This study investigates a graphitic carbon nitride/iron oxide (Fe₂O₃/g–C₃N₄ or FC) nanocomposite as a dual–functional fertilizer to improve iron (Fe) nutrition and BNF in soybeans. A pot experiment was conducted using different FC concentrations (10, 100, and 200 mg kg⁻¹), alongside controls. Results showed that the 100 mg kg⁻¹ FC treatment (FC2) was most effective, significantly increasing soybean biomass, nodule number, and nodule fresh weight. The FC2 treatment also enhanced photosynthetic rates and chlorophyll content (SPAD values) while reducing stomatal conductance and transpiration, indicating improved water–use efficiency. Furthermore, FC application bolstered the plant’s antioxidant system by increasing the activity of superoxide dismutase (SOD) and peroxidase (POD). Elemental analysis confirmed that FC treatments significantly increased the uptake and translocation of Fe and nitrogen (N) in plant tissues. These findings demonstrate that the FC nanocomposite acts as a highly effective nanofertilizer, simultaneously addressing iron deficiency and boosting nitrogen fixation to promote soybean growth. This work highlights its potential as a sustainable solution to enhance crop productivity and nutrient use efficiency in modern agriculture. Full article

Silicon (Si) has emerged as a promising tool for mitigating the negative effects of biotic and abiotic stresses, such as caused by heavy metals, on plants. The aim of the study was to summarize knowledge about the mechanisms underlying the interaction between silicon and cadmium. This review first discusses silicon compounds in plant physiology, then examines mechanisms of silicon–cadmium interaction, including antioxidant defense, metal chelation, nutrient transport, molecular responses, subcellular changes, and future directions. Recent studies show that various forms of Si, such as conventional Si and Si-nanoparticles (Si NPs), can have various effects on the ability of a plant to absorb and utilize Si for protection. Silicon, taken up mainly as soluble orthosilicic acid (H₄SiO₄) and Si NPs, can be absorbed by plants and subsequently deposited predominantly in cell walls. It has been found that Si and Si NPs increase the activity of antioxidant enzymes, including CAT, SOD, and POD, in plants under cadmium (Cd) stress. Furthermore, Si reduces the expression of Cd transport-related genes, including OsNRAMP5 and OsHMA2 in rice. It has also been shown that supplementation with Si and Si NPs in plants under Cd stress reduces the Cd content in their tissues and changes the uptake of elements necessary for the proper functioning of the plant organism. Furthermore, Si supplementation increases the content of pectins, which are involved in the binding and neutralization of Cd. The following overview highlights the importance of both Si and SiNPs in neutralizing the harmful effects of Cd on the environment and agriculture. Full article

Soybeans (Glycine max L.), a globally significant crop, play a critical role in economic, nutritional, and ecological systems, particularly in rotational farming due to their nitrogen-fixing capacity. This study investigated the residual effects of vermicompost (VC) and vermicompost tea (VCT) applied during a preceding corn cycle on subsequent soybean growth and productivity in an organic corn–soybean rotation. Soybeans were grown in raised beds previously treated with different VCT concentrations and combinations of VC+VCT, without additional fertilization during the soybean phase. Physiological traits, including leaf chlorophyll content (SPAD values) and stomatal conductance, were measured alongside biomass, yield, and plant leaves nutrient concentrations. VC+VCT treatments significantly increased biomass and yield, with VC1+VCT20 achieving the highest biomass (3.02 tons/ha) and yield (1.68 tons/ha). Leaf nutrient analysis revealed increased uptake of both macro- and micronutrients in amended treatments, while SPAD and stomatal conductance values remained consistently higher than in the control. Soil analyses confirmed improved nutrient retention and cation exchange capacity in amended plots, demonstrating the legacy benefits of organic inputs. Therefore, residual VCT and VC+VCT applications improved soybean productivity, nutrient acquisition, and physiological performance in rotational systems. By reducing reliance on synthetic fertilizers and enhancing soil fertility, this strategy supports climate-smart agriculture principles and contributes to SDG 2 (Zero Hunger), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action). Full article

Fulvic acid’s potential to enhance plant growth has been recognized, but its effects on plant growth and nutrient uptake under nutrient stress remain unclear. This experiment investigated the effects of fulvic acid at concentrations of 0 mg L⁻¹ (T1), 30 mg L⁻¹ (T2), 60 mg L⁻¹ (T3), 90 mg L⁻¹ (T4), 120 mg L⁻¹ (T5), and 150 mg L⁻¹ (T6) on the growth performance of two rice varieties—Jikedao 654 (J 654) and Jiyang 100 (J 100)—under low-nitrogen stress in a hydroponic system. The effects of different fulvic acid application rates on the growth and photosynthetic characteristics, the key enzymes of nitrogen metabolism, antioxidant properties, and the osmotic adjustment substances of rice under low-nitrogen stress were evaluated. The results indicated that the addition of an appropriate concentration of fulvic acid could enhance the growth performance of J 654 and J 100 under low-nitrogen stress. Compared to T1 treatment, the total dry weight and nitrogen accumulation of rice showed greater increases in response to T3 and T4 treatments. The photosynthetic pigment content increased, photosynthesis was enhanced, and the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO₂ concentration (Ci), and transpiration rate (Tr) were improved. The activities of key enzymes in nitrogen metabolism, including nitrate reductase (NR), glutamine synthetase (GS), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase activity (GPT), were enhanced, thereby improving the capacity for nitrogen uptake and assimilation. The addition of fulvic acid also enhanced the antioxidant capacity, increased the superoxide dismutase (SOD), peroxide (POD) and catalase (CAT) activity and decreased the toxic effects of ROS, the production rate of O₂⁻, and the hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) content. The low-nitrogen stress was alleviated, thereby reducing the proline and soluble sugars content. Overall, it was demonstrated that adding an appropriate concentration (60–90 mg L⁻¹) of fulvic acid under low-nitrogen stress has a positive impact on the growth and development of rice. Our findings provide a theoretical basis for the application of fulvic acid in alleviating low-nitrogen stress in rice. Full article

Silicon (Si) is gaining recognition as a sustainable alternative to reduce insecticide use in the management of the Asian citrus psyllid and huanglongbing (HLB). This study aimed to evaluate the effects of two silicon sources and three application methods on Diaphorina citri incidence, soil chemical properties, and foliar nutrient uptake in a Tahiti lime orchard. Using a randomized block design, treatments were applied six times over three months. Foliar and combined applications of diatomaceous earth reduced vegetative flushing and decreased natural psyllid incidence by up to 75% in the first 30 days. While silicon did not affect oviposition in induced infestations, it disrupted the nymph-to-adult transition. Silicon also improved soil conditions, increasing pH, organic matter, and the availability of phosphorus, calcium, and magnesium. In leaf tissue, higher levels of nitrogen, phosphorus, potassium, iron, and silicon (0.28–0.50%) were observed. Fruit quality improved with silicon, showing greater fresh weight (134 g) and juice content (44.7%) compared to the control (95.33 g and 28.5%). The results suggest that silicon’s effectiveness depends more on its availability and application method than its source. Incorporating silicon, especially diatomaceous earth, into fertilization programs supports pest control, enhances soil and plant nutrition, and improves fruit quality. Full article

Soil acidification from excessive nitrogen and potassium fertilization in protected cucumber systems impairs calcium uptake, triggering physiological calcium deficiency and reducing yield. We investigated whether the plant growth-promoting rhizobacterium Bacillus amyloliquefaciens QST713 could mitigate low-calcium stress in cucumber (‘Jinyou No. 4’). Under controlled nutrient solution irrigation (4, 0.4, and 0 mmol/L Ca²⁺, with or without B. amyloliquefaciens QST713), low-calcium conditions suppressed growth, reduced ion uptake capacity, photosynthetic pigment content, gas exchange (Pn, Gs, Tr), PSII efficiency (ΦPSII, ETR), and decreased carbohydrate (starch, sucrose) accumulation, while disrupting nitrogen balance (decreases in NO₃⁻-N, soluble protein, and amino acids; increase in NH₄⁺-N) and inhibiting key N-assimilation enzymes (NR, GS, GOGAT, GDH). Inoculation with B. amyloliquefaciens QST713 reversed these effects: it enhanced ion acquisition, chlorophyll content, and photosynthetic performance; restored carbohydrate reserves; promoted NO₃⁻ uptake and NH₄⁺ assimilation; and upregulated N-metabolizing enzyme activities. Principal component analysis confirmed strong coupling among growth, photosynthesis, and C-N metabolism. In summary, low-calcium stress markedly inhibited cucumber growth, suppressed photosynthetic activity, and reduced the levels of carbon and nitrogen metabolism. Application of B. amyloliquefaciens QST713 effectively alleviated the physiological damage caused by low-calcium stress, enhancing photosynthetic performance and thereby accelerating the synthesis and turnover of carbon- and nitrogen-containing metabolites. These effects collectively improved cucumber tolerance to low-calcium conditions and promoted plant growth and development. This study provides a preliminary theoretical basis for further exploration of the stress-resistance capacity of B. amyloliquefaciens. Full article

Given the critical role of manganese (Mn) as an essential micronutrient in wheat growth and development and the high efficiency of foliar fertilization in optimizing nutrient uptake and improving crop quality, this study aimed to elucidate the regulatory effects of exogenous manganese sulfate application on wheat grain yield and carotenoid accumulation. Methods: Field experiments were conducted from 2022 to 2024 at the Shuitou Experimental Station of the Cotton Research Institute, Shanxi Agricultural University (35°11′ N, 111°05′ E), using the wheat cultivar ‘Jinmai 110’. Foliar applications of manganese sulfate were administered at concentrations of 0.5 g/kg, 1.0 g/kg, and 1.5 g/kg, with water serving as the control (CTRL). Spraying was conducted on the upper canopy during the flowering and grain-filling stages, applied every 7 days for a total of three times. Samples for transcriptomic analysis were collected within 24 h of the final application. At maturity, yield-related traits and grain carotenoid contents were assessed. Results: Foliar application of 1.0 g/kg MnSO₄ significantly enhanced both grain yield and carotenoid content in wheat. Transcriptome sequencing revealed that treatment with 1.0 g/kg manganese sulfate (M2) resulted in 4761 differentially expressed genes (DEGs), including 2933 upregulated and 1828 downregulated genes, relative to CTRL. Gene Ontology (GO) analysis showed that in the M2 vs. CTRL comparison, 819 GO terms were significantly enriched among upregulated DEGs and 630 among downregulated DEGs. Specifically, upregulated genes were associated with 427 biological process terms and 299 cellular component terms, while downregulated genes were linked to 361 biological processes and 211 cellular components. Enriched functions primarily included cellular processes, metabolic processes, catalytic activity, and binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed 809 annotations for upregulated DEGs and 330 for downregulated DEGs, mainly related to photosynthesis, carotenoid biosynthesis, phenylpropanoid biosynthesis, and plant hormone signal transduction. In total, 43,395 alternative splicing (AS) events were identified from 17,165 genes, including 445 upregulated and 319 downregulated AS events, primarily enriched in photosynthesis and plant hormone-related pathways. Conclusion: Foliar application of manganese sulfate significantly modulates gene expression in wheat grains, thereby improving both yield and carotenoid accumulation. Key biological processes affected include photosynthesis, plant hormone signal transduction, and the carotenoid biosynthetic pathway. The interactions among these regulatory networks constitute a complex molecular mechanism through which exogenous Mn influences agronomic traits. These findings provide mechanistic insights and practical implications for enhancing wheat productivity and nutritional quality through foliar manganese application. Full article