Search Results (390)

Nanofertilizers (NFs) and engineered nanoparticles (NPs) are increasingly used in agriculture, yet their environmental safety remains poorly understood. This study evaluated the comparative phytotoxicity of zinc oxide (ZnO), titanium dioxide (TiO₂), and clinoptilolite nanoparticles, three commercial nanofertilizers, and potassium dichromate (K₂Cr₂O₇) using Lactuca sativa seeds under adapted OECD-208 protocol conditions. Seeds were exposed to varying concentrations of each xenobiotic material (0.5–3% for NFs; 10–50% for NPs), with systematic assessment of seedling survival, root and hypocotyl length, dry biomass, germination index (GI), and median effective concentration (EC₅₀) values. Nanofertilizers demonstrated significantly greater phytotoxicity than engineered nanoparticles despite lower application concentrations. The toxicity ranking was established as NF1 > NF3 > NF2 > NM2 > NM1 > NM3, with NF1 being most toxic (EC₅₀ = 1.2%). Nanofertilizers caused 45–78% reductions in root length and 30–65% decreases in dry biomass compared with controls. GI values dropped to ≤70% in NF1 and NF3 treatments, indicating concentration-dependent growth inhibition. While nanofertilizers offer agricultural benefits, their elevated phytotoxicity compared with conventional nanoparticles necessitates rigorous pre-application safety assessment. These findings emphasize the critical need for standardized evaluation protocols incorporating both physiological and ecotoxicological endpoints to ensure safe xenobiotic nanomaterial deployment in agricultural systems. Full article

Drought stress has a significant impact on cotton growth, development, and productivity. This study conducted drought stress treatment and normal water treatment (control group) on 502 cotton accessions and analyzed data on eight phenotypic traits closely related to drought stress tolerance. The results showed that all indicators changed significantly under drought stress conditions compared to the control group, with varying degrees of response among different indicators. To comprehensively evaluate the drought resistance of cotton during the germination period, the values of drought resistance comprehensive evaluation (D-value), weight drought resistance coefficient (WDC-value), and comprehensive drought resistance coefficient (CDC-value) were calculated based on membership function analysis and principal component analysis. Cluster analysis based on the D-value divided the germplasm into five drought-resistant grades, followed by the selection of one extreme material, each from the strongly drought-resistant and strongly drought-sensitive groups. An evaluation model was established using stepwise regression analysis, including the following effective indicators: Relative Fresh Weight (RFW), Relative Hypocotyl Length (RHL), Relative Seeds Water Absorption Rate (RAR), Relative Germination Rate (RGR), Relative Germination Potential (RGP), and Relative Drought Tolerance Index (RDT). The validation of the D-value prediction model based on the Best Linear Unbiased Prediction (BLUP) showed that the results obtained from two independent biological replicates were highly consistent. The comprehensive evaluation system and screening indicators established in this study provide a reliable method for identifying drought tolerance during the germination period. Full article

Bombax ceiba is an important medicinal and ornamental tree widely distributed in tropical and subtropical areas. However, its seeds lose viability rapidly after harvest, which has created hurdles in large-scale propagation. Here, we describe the development of a rapid and efficient de novo organogenesis system for Bombax ceiba, incorporating both indirect and direct regeneration pathways. The optimal basal medium used throughout the protocol was ½ MS supplemented with 30 g/L glucose, with all cultures maintained at 26–28 °C. For the indirect pathway, callus was induced from both ends of each hypocotyl on basal medium supplemented with 0.2 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg·L⁻¹ 6-Benzylaminopurine (6-BA) under dark conditions. The induced calluses were subsequently differentiated into adventitious shoots on basal media containing 0.5 mg·L⁻¹ Indole-3-butyric acid (IBA), 0.15 mg·L⁻¹ Kinetin (KIN), and 1 mg·L⁻¹ 6-BA under a 16 h photoperiod, resulting in a callus induction rate of 140% and a differentiation rate of 51%. For the direct regeneration pathway, shoot buds cultured on medium with 0.5 mg·L⁻¹ IBA and 1 mg·L⁻¹ 6-BA achieved a 100% sprouting rate with a regeneration coefficient of approximately 3.2. The regenerated adventitious shoots rooted successfully on medium supplemented with 0.5 mg·L⁻¹ Naphthylacetic acid (NAA) and were acclimatized under greenhouse conditions to produce viable plantlets. This regeneration system efficiently utilizes sterile seedling explants, is not limited by seasonal or environmental factors, and significantly improves the propagation efficiency of Bombax ceiba. These optimized micropropagation methods also provide a robust platform for future genetic transformation studies using hypocotyls and shoot buds as explants. Full article

In vitro micropropagation is used to rapidly shorten the breeding process of crops, such as kale, an internationally widespread winter vegetable. The aim of this study is to develop optimised micropropagation protocols for three kale varieties. First, it was determined which seed surface disinfection method resulted in the highest germination rate and the lowest infection rate. Secondly, it was investigated which of several existing Brassica protocols and one modified protocol from the literature provided the highest regeneration efficiency of kale explant types (cotyledons, hypocotyl, root, and intact seedlings as the control) after eight weeks of cultivation. Germination was highest and fastest after disinfection with 10% NaClO for 10 min for “Frostara” and at 5% for 2.5 min for “Schatteburg”. The infection rate and speed were lowest in treatments with 10% NaClO. The regeneration efficiency and number of newly formed leaves, roots, shoots, and stems varied between media, explant type, and kale variety. Most new leaves and shoots were formed when hypocotyls were used as explant type. Roots regenerated mostly more roots than shoots, stems, and leaves. A higher ratio of auxin to cytokinin in the culture medium partially increased leaf regeneration. The addition of AgNO₃ increased shoot regeneration and reduced yellowing and leaf drop. Phenotypic anomalies occurred less frequently in media with lower hormone concentrations. All tested protocols are suitable for kale micropropagation, but regeneration was highly dependent on the medium for different varieties and explant types. Therefore, this study builds a basis for future micropropagation of kale and the development of variety-specific protocols for maximum commercial success. Full article

Chickpea is a legume that grows in most parts of the world. It is negatively affected by abiotic and biotic factors like drought and fungal diseases, respectively. One of the most important soil-borne pathogens affecting chickpeas is Fusarium oxysporum f.sp. ciceris (Foc). Its population dynamics in the soil are affected by fluctuations in soil water content and host characteristics. For the last three decades, drought has been common in most areas of the world due to global warming. Drought stress decreases the quality and quantity of the chickpeas, particularly where soil-borne pathogens are the main stress factor for plants. The use of both drought-tolerant and disease-resistant cultivars may be the only option for cost-effective yield production. In this study, we screened the seeds of twelve chickpea genotypes WR-315, JG-62, C-104, JG-74, CPS-1, BG-212, ANNIGERI, CHAFFA, BG-215, UC-27, ILC-82, and K-850 for drought tolerance at increasing polyethylene glycol (PEG) concentrations (0-, 5-, 7.5-, 10-, 15-, 20-, 25-, 30- and 50%) to create drought stress conditions at different severities. The performances of genotypes that were previously tested in Foc resistance/susceptibility studies were assessed in terms of percentage of germination, radicle and hypocotyl length, germination energy, germination rate index, mean germination time, and vigor index in drought conditions. We determined the genotypes of C-104, CPS-1, and WR-315 as drought-susceptible, moderately drought-tolerant, and drought-tolerant, respectively. We then elucidated the stress levels of selected genotypes (20-day-old seedlings) at 0–15% PEG conditions via measuring proline and malondialdehyde (MDA) contents. Our findings showed that genotypes that were resistant to Foc also exhibited drought tolerance. The responses of chickpea genotypes infected with Foc under drought conditions are the next step to assess the combined stress on chickpea genotypes. Full article

Regional increases in atmospheric O₃ are phytotoxic not only to major crops but also to root vegetables such as radish, and their effects can be further modulated by nitrogen (N) addition. To assess how cherry radish responds to elevated O₃ (eO₃) under N addition and to compare the dose–response relationships, we established six open-top chambers with two O₃ levels and two N treatments in Beijing, China, to examine gas exchange, growth, and biomass throughout the growing period. The results showed that: 1. eO₃ had a “priming effect” on photosynthesis rates (Pn) at the beginning of the experiment. N addition alleviated the O₃-induced Pn reduction at the end of the experiment by 6.76% but did not significantly influence the O₃-dose response to Pn; 2. stomatal conductance (gs) did not have a dose response to all treatments while evaporation rates (E) showed strong negative regression with AOT40; 3. N addition reduced the hypocotyl biomass (−47.70%), leaf biomass (−32.22%), and the whole plant biomass reduction caused by O₃ (−38.47%) at the end of the experiment, but N addition did not significantly influence O₃-dose response to biomass. In conclusion, N addition can alleviate O₃-induced reductions in Pn and biomass via non-stomatal mechanisms, but it is ineffective in altering long-term O₃ dose–response relationships. Soil N addition offers a short-term strategy to mitigate O₃ impacts on short-lived root vegetables such as cherry radish but does not influence key functional traits over the long term. This study highlights the potential of N addition to alleviate acute oxidative stress, while underscoring its limitations in mitigating the effects of prolonged O₃ exposure in root vegetables. Full article

Salt stress is a significant abiotic factor that adversely impacts the yield of rapeseed (Brassica napus L.). Under salt stress conditions, the growth of rapeseed is markedly inhibited. This study integrates transcriptomic and metabolomic analyses to elucidate the molecular and physiological mechanisms underlying the salt stress response during the germination of the rapeseed variety ZS11. Metabolomic analysis revealed 175 differentially expressed metabolites, predominantly comprising amino acids, carbohydrates, and organic acids. Transcriptomic analysis highlighted the crucial roles of plant hormones and phenylpropanoid biosynthesis in enhancing the salt stress resistance of rapeseed. Comprehensive multi-omics analysis identified phenylpropanoid metabolism (p < 0.001), amino acid metabolism (FDR < 0.01), and carbohydrate metabolism (|log₂FC| ≥ 2) as the most significantly affected pathways. Crucially, we demonstrate that early-stage phenylpropanoid activation in hypocotyls dominates salt adaptation during germination. These findings provide actionable targets for molecular breeding and novel insights for optimizing crop establishment in salinized agroecosystems. Full article

The AP2/ERF transcription factor ABSCISIC ACID INSENSITIVE 4 (ABI4) plays diverse roles in plant development and responses to abiotic stress. However, its potential involvement in regulating anthocyanin biosynthesis is not fully understood. In this study, three different loss-of-function abi4 alleles (abi4-1, abi4-2, and abi4-101) were employed to investigate the role of ABI4 in the regulation of anthocyanin accumulation in Arabidopsis seedlings. These abi4 mutants exhibited significantly increased anthocyanin accumulation, which was associated with elevated expression of genes involved in anthocyanin biosynthesis. HY5 (LONG HYPOCOTYL 5), a central component of photomorphogenesis, acts as a key light-regulated molecular switch. Further analysis revealed that ABI4 requires HY5 to function as a negative regulator of anthocyanin biosynthesis. Additionally, loss of ABI4 resulted in heightened light sensitivity, leading to increased light-induced chlorophyll accumulation and chloroplast development, along with upregulation of photosynthesis-related genes. Interestingly, the light-hypersensitive phenotype of abi4 mutants was partially rescued by the loss of HY5 function. Taken together, these findings demonstrate that ABI4 negatively regulates anthocyanin accumulation in Arabidopsis seedlings through a HY5-dependent light signaling pathway. Full article

Dense planting and intercropping are the main ways to improve soybean production. However, both confront inter- and intra-crop shading stress. This leads to stem elongation, resulting in lodging and yield losses. Most previous studies have focused on the later growth stages for shade tolerance. However, it has been found that the seedling stage is crucial, and understanding the genetic basis of shade tolerance at this stage is pivotal for yield improvement. In this study, 310 soybean accessions were used to evaluate shade tolerance under greenhouse conditions. Plant height (PH), main stem length (MSL), and hypocotyl length (HL) were examined at seedling stage, and their treatment/control ratios (PH_r, MSL_r, HL_r) were used for genetic dissection of shade tolerance. Their overall phenotypic variation and heritability (H²) ranged 22.97–36.85% and 31.66–83.81%, respectively. RTM-GWAS identified 12, 10, and 6 QTLs associated with PH_r, MSL_r, and HL_r, respectively. Among these, Block_17_11907536_11926235 was associated with both PH_r and MSL_r, and Block_1_55630414_55715065 associated with the HL_r trait showed the highest contribution (R² = 10.38%). Additionally, seven promising candidate genes, primarily linked to ethylene-responsive transcription factors, were proposed, supported by their established roles in plant development and stress responses, as evidenced in prior studies. The germplasm, QTLs, and candidate genes identified in this study improve our understanding of shade tolerance and have the potential to accelerate the breeding of shade-resilient soybeans. Full article

Root-knot nematodes (RKNs), specifically Meloidogyne incognita, are notoriously difficult to eliminate as endophytic nematodes, and cause severe damage to various plants. Cucumber (Cucumis sativus), which is a cash crop widely grown across the world, is often infected by RKNs. ELONGATED HYPOCOTYL5 (HY5), a member of the bZIP transcription factor family, plays a vital role in hormone, nutrient, abiotic stress, biotic stress, and oxygen species (ROS) signaling pathways. However, the involvement of HY5 in the defense against RKNs has rarely been reported. The present study initially explored the response of CsHY5 to RKNs. The results indicated that the hy5 mutant had a higher number of nematodes and galls in the root system and exhibited a higher susceptibility to RKNs compared with the wild type (WT). Particularly, the root-knot nematodes in hy5 plants completed their life cycle more quickly and produced more eggs. The activities of defense-related hormones and antioxidant enzymes were measured, and the results indicated that JA, jasmonoyl-isoleucine (JA-Ile), abscisic acid (ABA), peroxidase (POD), and ascorbate peroxidase (APX) were significantly elevated in the wild type, but were not induced or decreased in the mutant. Through transcriptome sequencing analysis and quantitative real-time PCR (qRT-PCR), it was found that when RKNs infect plants, the key genes of jasmonic acid (JA) synthesis, CsAOC and CsAOS, as well as the key gene of the antioxidant system, CsPOD, were all significantly induced. Nevertheless, this induction effect disappeared in the hy5 mutant. Generally, CsHY5 plays a role in the response of cucumber to RKNs, and its deletion increases the sensitivity of cucumber to RKNs. These results suggest that CsHY5 may affect the resistance of cucumber to RKNs by affecting antioxidant enzyme activities and hormone content. Full article

This study aimed to elucidate the specific role of low NaCl concentrations, particularly 10 and 20 mM, in stimulating cotyledon growth in Chinese white radish (Raphanus sativus L. var. longipinnatus Bailey) seedlings. Chinese white radish seeds were cultivated in sand culture and subjected to daily watering with solutions containing 0, 10, 20, 50, or 100 mM NaCl. Growth, water status, aquaporin gene expression, ion contents, and physiology-related parameters were assessed 4 days after sowing. Applying 10 and 20 mM NaCl significantly promoted the growth of 4-day-old seedlings. Notably, the cotyledons exhibited the most significant growth, achieving a rate of 177% compared with the 125–138% growth observed in the hypocotyl and root parts. This substantial enhancement in cotyledon growth, including biomass, cotyledon area, cotyledon thickness, and mesophyll cell size, was induced by an optimal concentration of 10 mM NaCl. This induction correlated with the increased water content, degree of succulence, and expression of aquaporin genes, specifically within PIP1-1, PIP1-2, PIP2-1, PIP2-2, and TIP1-1, in addition to the maintenance of the Hill reaction, heightened free radical scavenging, and the elevated accumulation of Na⁺, Cl⁻, K⁺, proline, total N, and C. These findings suggest a beneficial role of low NaCl levels in optimising early-stage seedling growth. Full article

Cannabis sativa produces pharmacologically valuable cannabinoids. In this study, we developed and optimized a transient transformation system using Cannabis sativa ‘Cheungsam’ to facilitate gene functional analysis. Various experimental conditions, including plant developmental stages, light conditions, Agrobacterium strains, tissue types, and physical treatments such as sonication and vacuum infiltration, were systematically evaluated using GUS histochemical staining and qPCR analysis. Among these, 7-day-old seedlings cultured under dark conditions and transformed with the GV3101 strain exhibited high transformation efficiency. Leaf tissue showed a higher GUS staining proportion and GUS staining area compared to hypocotyl and cotyledon tissues. The application of a combination of sonication and vacuum infiltration techniques resulted in the most intense GUS expression. Using the optimized protocol, we introduced a recombinant vector carrying CsCBDAS2, a key gene in cannabidiol (CBD) biosynthesis. qPCR analysis revealed that CsCBDAS2 overexpression led to significant upregulation of multiple upstream CBD biosynthetic genes (CsOAC, CsGOT, CsPT1, CsPT4, CsCBDAS1, and CsCBDAS2) and the transcription factor (TF) CsWRKY20, suggesting coordinated co-expression and potential involvement of a transcriptional feedback loop. These results demonstrate the effectiveness of our transient transformation system and provide insights into the regulatory mechanisms of cannabinoid biosynthesis in cannabis. Full article

Blue light serves as a critical environmental cue regulating Glycine max (soybean) stem morphology, yet the hormonal mechanisms underlying varietal differences remain unclear. Previous studies have highlighted the role of blue light in modulating plant architecture, but the specific hormone interactions driving morphological divergence between soybean varieties remain underexplored. Two soybean varieties with contrasting stem phenotypes—Henong 60 (HN60, tall) and Heinong 48 (HN48, dwarf)—were subjected to 0% (full light) and 30% (shade) transmittance conditions, supplemented with blue light (450 nm, 45.07 ± 0.03 μmol·m⁻²·s⁻¹). Stem anatomical traits (xylem area, cell length), hormone profiles, and proteomic changes were analyzed. Grey correlation analysis quantified relationships between hormone ratios and plant height. Blue light increased soybean stem xylem area and diameter while reducing plant height and cell longitudinal length. This treatment concurrently reduced growth-promoting hormones (gibberellin A₃ (GA₃), indole-3-acetic acid (IAA), brassinolide (BR)) and increased growth-inhibiting hormones (salicylic acid (SA), jasmonic acid (JA), strigolactones (SLs)), thereby inhibiting stem elongation. Although exogenous GA₃ promoted hypocotyl elongation, it failed to counteract blue-light-induced inhibition. Proteomic analysis identified 16 differentially expressed proteins involved in hormone signal transduction pathways. Grey correlation analysis highlighted cultivar-specific hormone ratio impacts: GA₃/JA, GA₃/SA, and BR/SLs significantly influenced HN60 plant height, while GA₃/SLs, IAA/SLs, and BR/SLs were critical for HN48, demonstrating highly significant positive correlations. The differential sensitivity of growth-promoting/inhibiting hormone ratios to blue light drives varietal morphological divergence in soybean stems. This study establishes a hormonal regulatory framework for blue-light-mediated stem architecture, offering insights for crop improvement under light-limited environments. Full article

Eruca sativa has been widely chosen among species to be cultivated in plant factories as microgreens, especially due to its nutraceutical and sensory qualities. Thus, the objective of this study was to evaluate the impact of blue light intensity (5 and 20 μmol m⁻² s⁻¹) and exposure time (1 and 2 h per day) on the yield and quality of arugula microgreens in plant factories. Blue light supplemental to white light for 1 h did not impair the hypocotyl lengths (HLs) or cotyledon area (CA) and yield of arugula microgreens compared with those grown only with white light. However, when the blue light time increased from 1 to 2 h, there were reductions in HL, CA and yield, with greater reductions under 20 μmol m⁻² s⁻¹. The concentrations of chlorophylls, carotenoids, vitamin C and antioxidant power responded similarly to the supply of blue light and were maximized with 20 μmol m⁻² s⁻¹. In view of these results, the supplementation of blue light with 20 μmol m⁻² s⁻¹ for 1 h is proposed, since it did not cause a reduction in growth and yield parameters and promoted the agronomic biofortification of arugula microgreens, bringing nutraceutical and, therefore, commercial benefits to the producer and consumer. Full article

The present study aimed to investigate the effects of exogenous carnitine treatments on maize seed germination by stimulating lipid metabolism and regulating the mitochondrial respiratory pathway. Maize seeds were grown as control, 5, 7.5, and 10 μM carnitine treatment groups in a germination chamber at 25 °C under dark conditions for 5 d. It was determined that carnitine treatments increased the germination rate (GR), germination index (GI), germination potential (GP), vigor index (VI), root and hypocotyl length, fresh weight (FW), and content of total soluble protein but decreased the total carbohydrate content. It was also found that it increased the activities of α-amylase, isocitrate lyase (ICL), and malate synthase (MS) enzymes, which are critical in the germination process, and upregulated the expression of ICL and MS genes. To clarify the potential of carnitine treatments to promote the participation of lipids in respiration in roots and hypocotyls, lipase, carnitine acyltransferases (CATI and CATII), and citrate synthase (CS) enzyme activities were examined, and significant increases in these activities were detected. It was also found that gene levels of respiratory enzymes cytochrome oxidase (COX), pyruvate dehydrogenase (PDH), and Atp synthase, lipase, and CS proteins were upregulated by carnitine treatment. In support of the enzyme and gene change findings, significant changes were determined in fatty acid contents, free carnitine, and long-chain acylcarnitine levels in seeds, roots, and hypocotyls depending on carnitine application. In roots and hypocotyls, carnitine treatments significantly increased glutamine synthase (GS) and glutamate dehydrogenase (NADH-GDH) activities and gene expression levels, which are closely related to the tricarboxylic acid cycle (TCA). It was also noted that all proteins analyzed at the gene expression level were upregulated by carnitine applications in seeds. In addition, significant increases were recorded in antioxidant enzyme ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities and total ascorbate (AsA) and glutathione (GSH) contents in roots and hypocotyls, while decreases were determined in guaiacol peroxidase (GPX) and catalase activities. Significant changes were recorded in all parameters examined, especially with 7.5 µM carnitine application. The findings suggest that carnitine may promote the transport of fatty acids to mitochondrial respiration by accelerating lipid catabolism in five-day-old maize and contribute to seed germination and growth and development processes by activating other metabolic pathways associated with respiration in this process. Full article