Search Results (489)

Synthetic chemicals, such as fertilizers and pesticides, are widely used in agriculture to improve soil fertility and to control weeds, pests and diseases. Numerous studies have highlighted the negative effects of these chemicals on the soil environment. In contrast, during vermicomposting, earthworms generate numerous beneficial outcomes. This study aimed to screen antagonistic bacteria found after vermicomposting for their potential to inhibit the pre-emergence damping-off of tomato seedlings caused by Rhizoctonia solani. Using a dual culture method, 85 bacterial isolates were screened, three of which demonstrated antagonistic activity against R. solani. Molecular characterization based on 16S ribosomal RNA identified the bacterial isolates as Bacillus subtilis (NOAC.B77), Bacillus vallismortis (NOAC.B42), and Bacillus cereus (NOAC.B17). The strains NOAC.B77 and NOAC.B42 exhibited the most significant inhibitory effects on the mycelial growth of R. solani, with inhibition levels of 80.8% and 79.2%, respectively. In greenhouse trials, only 13% of the Inoculated, Unprotected Control tomato seedlings emerged, i.e., the R. solani inoculum caused an 87% level of preemergence damping off. In contrast, after treatment with the bacterial strains NOAC.B77 and NOAC.B42, tomato seedling emergence was not significantly different from the Uninoculated Control. These results suggest that the bacterial strains NOAC.B77 and NOAC.B42 could be commercialized as biological agents to control damping-off of tomato seedlings under greenhouse conditions. Full article

Although salt acclimation is a recognized strategy for improving crop salt tolerance, its specific role in tomato (Solanum lycopersicum L.) remains unclear. This study investigated the effects of salt acclimation on enhancing salt tolerance in tomato seedlings through physiological and transcriptomic analyses. Here, we found that T3 acclimation treatment (irrigation with 14 mL of 7.5 g L⁻¹ NaCl solution per plant) effectively conferred enhanced salt tolerance in tomato seedlings, with plant height, stem diameter, leaf area, chlorophyll content, net photosynthetic rate, and soluble protein content increasing by 4.52, 5.13, 3.16, 10.78, 11.85, and 25.96%, respectively, compared with the control. T3 treatment also reduced oxidative damage and ionic stress, as evidenced by reduced electrolyte leakage, lower malondialdehyde content, and a decreased root Na⁺/K⁺ ratio, while simultaneously boosting antioxidant enzyme activities. Membership function analysis confirmed T3 as the optimal treatment, with a 9 d duration consistently benefiting multiple cultivars. Transcriptomic analysis revealed that salt acclimation upregulated genes associated with phenylpropanoid biosynthesis, lignin catabolic process, and peroxidase activity, suggesting that these pathways might mediate acclimation-induced salt tolerance through promoting lignin biosynthesis to reduce Na⁺/K⁺ ratio and enhancing reactive oxygen species’ scavenging capacity to maintain cellular homeostasis. Our results indicate that tomato seedlings acclimated with 14 mL of 7.5 g L⁻¹ NaCl solution per plant for 9 d significantly improves salt tolerance through coordinated physiological adjustments and transcriptional reprogramming. Full article

Drought poses a major challenge for global agriculture, demanding strategies that improve crop resilience while safeguarding water and nutrient resources. Plant growth-promoting rhizobacteria (PGPR)-based biostimulants offer a sustainable approach to enhance resource-use efficiency under water-limited conditions. This study evaluated two commercial PGPR biostimulants applied to maize (Zea mays L.) and tomato (Solanum lycopersicum L.) seedlings grown under well-watered (80% field capacity) and water-stressed (40% field capacity) conditions. Both products improved plant growth and physiological performance, although responses were crop-specific. Inoculated tomato seedlings accumulated up to 35% more shoot biomass under optimal watering (1.6 g in non-inoculated seedlings compared with 2.5 g in inoculated seedlings), whereas maize maintained biomass production under drought, consistent with its higher intrinsic water-use efficiency, showing increases of approximately 50% (well-watered: 0.5 g versus 0.8 g; water-stressed: 0.3 g versus 0.7 g in non-inoculated and inoculated seedlings, respectively). Biostimulant application enhanced the acquisition and internal utilization of essential mineral resources, increasing leaf concentrations of (i) the macronutrients P (up to 300%), K (up to 70%), Mg (up to 220%), and Ca (up to 85%), and (ii) the micronutrients B (up to 400%), Fe (up to 260%), Mn (up to 240%), and Zn (up to 180%). Maximum nutrient increases were consistently observed in water-stressed maize seedlings inoculated with biostimulant 2. Antioxidant activities, particularly ascorbate peroxidase and catalase, increased by 20–40%, indicating more effective mitigation of oxidative stress. Principal component analysis revealed coordinated adjustments among growth, nutrient-use efficiency, and physiological traits in inoculated plants. Overall, PGPR-based biostimulants improved early drought tolerance and resource-use efficiency, supporting their potential as sustainable tools for climate-resilient agriculture. Field-scale studies remain necessary to confirm long-term agronomic benefits. Full article

Point-of-care diagnostics are revolutionizing the detection of plant pathogens by enabling rapid, on-site identification without the need for specialized laboratories. One of the tools used for this purpose is loop-mediated isothermal amplification (LAMP). LAMP is a powerful molecular technique increasingly used in pathogen control for its rapid, sensitive, and specific detection of plant pathogens. The aim of this study was the development of a novel, easy-to-use portable colorimetric LAMP (cLAMP) assay that could be used by inexperienced personnel for the detection of the pathogen Clavibacter michiganensis. The assay was combined with a newly constructed device in which LAMP can be performed in 30 min. Initially, a new set of LAMP primers targeting the micA gene was designed and evaluated the sensitivity (100 fg/reaction) and specificity of the assay. Next, the limit of detection (LoD) of two different commercial LAMP kits was compared with common laboratory detection techniques (DAS-ELISA, immunofluorescence, quantitative PCR, and PCR) using the same samples. Additionally, the LoD of the developed cLAMP assay was evaluated in bacterial suspensions and plant extracts spiked with C. michiganensis and validated the effect on the LoD of plant extracts from different tomato varieties. Lastly, its efficacy for C. michiganensis detection was assessed in experimentally inoculated tomato seedlings. The developed method for C. michiganensis detection can be used as a reliable tool for the early detection of the pathogen for field-based applications by untrained personnel. Full article

Tomato (Solanum lycopersicum L.) is an important horticultural crop. Carotenoid cyclase dioxygenase (CCD) is an enzyme responsible for cleaving carotenoids, which is involved in regulating plant growth and response to abiotic stresses. However, the role of SlCCDs in tomato stress resistance remains unclear. This study used the tomato variety ‘Micro-Tom’ as the material to investigate the function of SlCCDs in stress responses. Through whole-genome analysis, a total of 12 SlCCDs members (SlCCD1–SlCCD12) were identified. Systematic evolutionary analysis classified them into four branches, and members within the same branch maintained a conserved structure. The promoter analysis revealed that SlCCDs contain multiple hormones and stress response elements. The qRT-PCR analysis revealed that SlCCD11 was the most highly expressed gene in the leaves. In addition, multiple SlCCDs showed significant responses to abscisic acid (ABA), methyl jasmonate (MeJA), light, and sodium chloride (NaCl) treatments. Among them, the expression of SlCCD11 significantly increased under salt stress. By silencing SlCCD11 using virus-induced gene silencing (VIGS) technology, it was found that the chlorophyll content, antioxidant enzyme activity, and ABA-related gene expression in the TRV:SlCCD11 plants under salt stress were all lower than the control samples, while the carotenoid content and ROS accumulation were higher. This indicates that SlCCD11 is a positive regulatory factor for salt stress. In conclusion, this study systematically analyzed the SlCCD gene family and revealed the positive role of SlCCD11 in tomato response to salt stress, providing a candidate gene for genetic improvement of crop stress resistance. Full article

To further improve the prediction accuracy for greenhouse crop evapotranspiration (ET) under different irrigation conditions and enhance irrigation water use efficiency, this study proposes three methods to revise the Priestley–Taylor (PT) model coefficient α for calculating ET at different growth stages: (1) considering the leaf senescence coefficient f_S, plant temperature constraint parameter f_t, and soil water stress index f_sw to correct α (MPT model); (2) combining the Penman–Monteith (PM) model to inversely calculate α (PT-M model); (3) using the machine learning XGBoost algorithm to optimize α (PT-M_(XGB) model). Accordingly, this study observed the cumulative evaporation (Ep) of a 20 cm standard evaporation pan and set two different irrigation treatments (K0.9: 0.9Ep and K0.5: 0.5Ep). We conducted field measurements of meteorological data inside the greenhouse, tomato physiological and ecological indices, and ET during 2020 and 2021. The above three methods were then used to dynamically simulate greenhouse tomato ET. Results showed the following: (1) In 2020 and 2021, under K0.9 and K0.5 irrigation treatments, the MPT model mean coefficient α for the entire growth stage was 1.27 and 1.26, respectively, while the PT-M model mean coefficient α was 1.31 and 1.30. For both models, α was significantly lower than 1.26 (conventional value) during the seedling stage and the flowering and fruiting stage, rose rapidly during the fruit enlargement stage, and then gradually declined toward 1.26 during the harvest stage. (2) Predicted ET (ET_e) using the PT-M model underestimated the observed ET (ET_m) by 8.71~16.01% during the seedling stage and the harvest stage, and overestimated by 1.62~6.15% during the flowering and fruiting stage and the fruit enlargement stage; the errors compared to ET_m under both irrigation treatments over two years was 0.1~3.3%, with an R² of 0.92~0.96. (3) The PT-M_(XGB) model achieved higher prediction accuracy, with errors compared to ET_m under both irrigation treatments over two years of 0.35~0.65%, and R² above 0.98. The PT-M_(XGB) model combined with the XGBoost algorithm significantly improved prediction accuracy, providing a reference for the precise calculation of greenhouse tomato ET. Full article

The quality and yield of grafted tomato seedlings are significantly influenced by the selection of high-quality and robust rootstocks. The effectiveness of these rootstocks is dependent on various environmental factors and genetic traits. One of the most critical factors in cultivation is light, as its intensity plays a vital role in seedling growth, overall development, metabolic processes, the efficiency of the photosynthetic system, and other essential plant functions. The aim of this study was to investigate the changes in the photosynthetic system activity and the growth of tomato rootstocks depending on the light intensity. The study was conducted at the Institute of Horticulture, Lithuanian Center for Agricultural and Forestry Sciences, focusing on four tomato rootstock varieties grown in a controlled environment. The plants were grown at a temperature of +23/19 °C and a relative humidity of 55–60%, under different levels of illumination (high-pressure sodium lamps), PPFD: 150, 250 and 350 ± 10 µmol m⁻² s⁻¹. The results indicated that optimal growth and biomass accumulation occurred at around 250 µmol m⁻² s⁻¹, with the most significant growth observed in the rootstocks ‘Auroch’ and ‘Goldrake’. Higher light intensities, specifically at 350 µmol m⁻² s⁻¹, did not consistently enhance growth and could even lead to a reduction in leaf area and overall growth in some cultivars such as ‘Auroch’ and ‘TOR23901’. Although photosynthetic parameters improved with increased light intensity up to 350 µmol m⁻² s⁻¹, these enhancements did not translate into additional growth benefits. Full article

The presence of Bacillus subtilis on tomato roots contributes to plant growth promotion, which depends on its ability to establish in the roots. Edible-film formulations have emerged as effective carriers for beneficial bacteria. In this study, we evaluated film formulations based on guar gum, glycerol, and candelilla wax incorporating B. subtilis for root application in tomato seedlings to stimulate plant development. Sixteen film formulations were prepared and applied to seedling by dipping root; plants were grown under a 16/8 h photoperiod. At 60 days, growth parameters (plant height, leaf number, chlorophyll content, fresh and dry weights) were measured, along with B. subtilis on roots, and the soil degradation of the selected film. Treatments were: seedlings with B. subtilis at two doses (10^6,12 CFU/mL (B6, B12), film without bacteria (P), films with B. subtilis (P1–P16), and untreated (TST). Among the films, formulation 9 (guar gum 0.6%, candelilla wax 0.15%, glycerol 0.15% and B. subtilis 20%, 1 × 10¹²) significantly increased shoot and root biomass and supported higher root colonization of B. subtilis (2.3 × 10⁷ CFU/g). The film degraded in soil within 15 days, while the inoculant maintained high viability (6.3 × 10⁸ CFU/mL) after 8 months at 4 °C. These results highlight film formulation 9 as a promising bioinoculant for tomato cultivation. Full article

Frequent extreme weather events exacerbate agricultural abiotic stress, with drought causing widespread yield loss. Tomato, a globally important vegetable sensitive to water deficit, has been predominantly studied under single-drought scenarios that poorly reflect recurrent field conditions. This study investigated physiological and molecular responses of two tomato genotypes to repeated drought stress. Results showed that the drought-sensitive genotype ‘TGTB’ exhibited faster ABA accumulation and more pronounced ABA-mediated stomatal closure. During the second drought cycle, stomatal pore length and width were significantly smaller than during the first drought, indicating a strong stress memory effect. In contrast, the drought-tolerant ‘LA1598’ showed minimal memory responses. Under extreme drought stress, primed and non-primed ‘TGTB’ plants showed significantly lower H₂O₂ content than controls, whereas primed ‘LA1598’ plants maintained a significantly lower O₂^·− production rate than non-primed plants during both extreme drought cycles. Antioxidant enzyme systems contributed to ROS homeostasis, supported by the regulation of key drought-responsive genes. This study demonstrates genotype-dependent memory capacity and reveals that drought priming enhances repeated drought tolerance through ABA-regulated stomatal adjustment. These findings provide a theoretical basis for improving tomato resilience to recurrent drought and supporting breeding of drought-tolerant varieties. Full article

Water scarcity is a major constraint to agricultural productivity, particularly in arid and semi-arid regions. This study evaluated the effects of gardening waste-based compost and compost tea (CT) on tomato (Solanum lycopersicum L.) plants subjected to osmotic and water deficit stress. The first experiment assessed seed germination and early growth under polyethylene glycol (PEG)-induced osmotic stress. An inverse correlation between PEG concentration and seed and plant development was found. CT improved the germination rate and early seedling development under moderate stress (2% PEG). The second experiment examined the effect of compost and CT on tomato growth in a 45-day pot trial under three irrigation levels: 100%, 60%, and 40% field capacity (FC). Compost-treated plants consistently showed significantly greater growth and biomass accumulation across all FC levels, especially under moderate water stress. In contrast, CT-treated plants showed a general reduction in growth parameters. In addition, there was a positive association between compost treatment and multiple growth traits, particularly under reduced irrigation conditions. These findings underscore the beneficial effects of compost on plant performance under drought conditions. Full article

5-Aminolevulinic acid (ALA) is a natural and environmentally friendly plant growth regulator that plays an important role in enhancing plant tolerance to a wide range of environmental stresses. Exogenous application of ALA enables rapid and efficient physiological regulation. Additionally, methyl jasmonate (MeJA) enhances salt tolerance in tomato seedlings by regulating ALA to promote jasmonic acid (JA) accumulation and strengthening the antioxidant defense system. To investigate how exogenous ALA alleviates salt stress physiologically, this study used ‘Condine Red’ tomato as the experimental material and examined the effects of MeJA-mediated ALA on the growth characteristics and stress tolerance mechanisms of tomato seedlings under salt stress. The results indicated that salt stress significantly inhibited tomato seedling growth, leading to marked reductions in biomass, chlorophyll content, and the enzymatic activities of POD, CAT, and APX. In contrast, SOD activity, MDA content, NPQ, soluble protein content, proline content, endogenous JA levels, and the expression of related genes were significantly increased. Under salt stress, exogenous application of ALA and MeJA alleviated the inhibitory effects on tomato seedlings. However, SHAM (salicylhydroxamic acid) aggravated salt stress damage to plants. The addition of ALA significantly mitigated these salt stress-induced injuries. These findings suggest that ALA may enhance salt tolerance in tomato seedlings by promoting JA accumulation and bolstering the antioxidant defense system. Full article

Zinc (Zn) is an essential trace element that plays a crucial role in plant growth and development, but excessive Zn can be stressful or even toxic to plants. The GLTP superfamily is critical for lipid metabolism and membrane stability maintenance, yet its function in plant Zn tolerance remains unclear. In this study, zinc stress treatment experiments were performed using transgenic apple calli, apple seedlings, Arabidopsis thaliana, and Solanum lycopersicum. Under Zn treatment, compared with the wild type (WT), the apple seedlings of the MbACD11 transgenic line exhibited significantly higher plant height and fresh weight, with increases of 5.87% and 93.21% respectively. Meanwhile, their MDA level, relative electrical conductivity, and accumulations of H₂O₂ and O₂⁻ were all significantly reduced, with decreases of 20.47%, 35.47%, 31.50%, and 36.78% respectively. Consistently, these data showed the same trend in calli, Arabidopsis thaliana, and tomato. These results demonstrated that the overexpression of MbACD11 significantly enhanced Zn tolerance in transgenic plants, and also verified that the function of this gene may be conserved across different species. In summary, this study establishes a molecular framework and theoretical basis for improving plant tolerance to Zn stress and paves the way for future mechanistic investigations. Full article

Low temperature severely limits tomato (Solanum lycopersicum) production, yet the molecular mechanisms governing cold tolerance—particularly those involving COLD1 and GPA1—remain incompletely defined. To address this, processing tomato lines overexpressing COLD1 or GPA1 were generated and evaluated for seedling-stage cold tolerance, with a focus on the expression of key genes such as SlICE1, SlCBF1, and SlCOR518 to elucidate the molecular pathways conferring enhanced cold tolerance. Under cold stress conditions (4 °C for 5 days), physiological and biochemical responses were compared between wild-type and transgenic lines. The results demonstrated that COLD1-overexpressing lines exhibited markedly greater cold tolerance than both wild-type and GPA1-overexpressing lines, notably displaying reduced wilting and membrane injury. At 4 °C, the activities of superoxide dismutase, peroxidase, and catalase in COLD1-overexpressing lines were 122%, 67.4%, and 97.4% higher than those in the wild type, and 44.7%, 21.0%, and 20.6% higher than in GPA1-overexpressing lines, respectively. Furthermore, hydrogen peroxide and superoxide levels were 33.4% and 40.6% lower in COLD1-overexpressing lines compared to the wild type, and 17.8% and 24.0% lower compared to GPA1-overexpressing lines, respectively. Osmolyte accumulation was more pronounced in COLD1 lines, with soluble sugar and proline levels 95.4% and 66.2% higher than in the wild type, and 30.9% and 23.6% higher than in GPA1 lines, respectively. Importantly, changes in key gene expression indicated that both transgenic lines enhance cold tolerance by modulating the ICE1-CBF-COR pathway. Collectively, these findings highlight the superior contribution of COLD1 to cold tolerance in tomato seedlings and provide insights into the molecular mechanisms underlying cold adaptation. Full article

Entomopathogenic fungi of the genus Beauveria are recognized for their dual role as insect pathogens and plant endophytes, however the majority of research efforts to date have centered on B. bassiana. To address this bias, we evaluated the endophytic traits of five Beauveria species (B. bassiana, B. brongniartii, B. aranearum, B. amorpha, and B. velata) in tomato (Solanum lycopersicum). Tomato seedlings were inoculated by root drenching with 1 × 10⁸ conidia/mL suspensions, and colonization, plant growth, and resistance to Botrytis cinerea were assessed. All five species colonized tomato tissues, with colonization rates from 33.3% (B. velata) to 56.7% (B. brongniartii). Growth promotion was species dependent: B. bassiana, B. brongniartii, and B. aranearum significantly increased plant height, while B. brongniartii enhanced aboveground biomass. In pathogen assays, all Beauveria-treated plants showed reduced gray mold incidence and severity, with B. brongniartii conferring complete protection. Transcriptome analysis identified 160 differentially expressed genes commonly regulated, including 17 upregulated genes enriched in defense responses, hormone signaling, and photosynthesis. These findings demonstrate that non-B. bassiana species can establish endophytic associations, promote growth, and induce resistance in tomato, expanding the potential of Beauveria spp. as biocontrol agents in sustainable agriculture. Full article

With-No-Lysine (WNK) kinases constitute a subgroup within the serine/threonine protein kinase family, characterized by the absence of a catalytic lysine residue in the kinase subdomain II located in their N-terminal region. These kinases play critical roles in regulating plant growth, development, and responses to abiotic stressors. However, members of the WNK and their responses to heat stress in pepper (Capsicum annuum L.) remain unexplored. In the present study, we identified eleven WNK genes within the genome of pepper cultivar ‘UCD-10X-F1’ and designated them CaWNK1 to CaWNK11 according to their chromosomal positions. Comprehensive analyses were conducted to elucidate their phylogenetic relationships, chromosomal distribution, collinearity, gene structure, protein properties, and cis-acting elements within promoter regions. The findings revealed that the CaWNK gene family segregates into five distinct subgroups. Comparative genomic analysis identified eleven and nine segmental duplication gene pairs between pepper and tomato and between pepper and Arabidopsis, respectively. Within the pepper genome, two pairs of segmentally duplicated genes and two pairs of tandemly repeated genes were also detected. The CaWNK gene sequences in pepper exhibited a high degree of conservation; however, variations were observed in the number of introns and exons. Analysis of the promoter regions revealed an abundance of cis-acting elements associated with growth and development, stress responses, and hormone regulation. Subsequent transcriptomic analyses demonstrated that CaWNK genes displayed tissue-specific expression patterns and differential expression levels following treatments with exogenous plant hormones and abiotic stresses. Notably, the expression of CaWNK6 was significantly up-regulated under heat stress conditions. To elucidate the functional role of CaWNK6, virus-induced gene silencing (VIGS) was employed to suppress its expression in pepper seedlings. Silencing of CaWNK6 resulted in disrupted tissue architecture, stomatal closure, and diminished heat tolerance. These phenotypic changes correlated with excessive accumulation of reactive oxygen species (ROS), reduced activity of antioxidant enzymes, and down-regulation of heat shock factor (HSF) genes in the silenced plants. Collectively, these findings offer valuable insights into the functional roles of CaWNK genes and hold significant implications for the development of novel heat-tolerant pepper cultivars. Full article