Plant hormone profiling of scion and rootstock incision sites and intra- and inter-family graft junctions in Nicotiana benthamiana

Many previous studies have suggested that various plant hormones play essential roles in the grafting process. In this study, to understand the plant hormones that accumulate in the graft junctions, whether these are supplied from the scion or rootstock, and how these hormones play a role in the grafting process, we performed a hormonome analysis that accumulated in the incision site of the upper plants from the incision as "ungrafted scion" and lower plants from the incision as "ungrafted rootstock" in Nicotiana benthamiana. The results revealed that indole-3-acetic acid (IAA) and gibberellic acid (GA), which regulate cell division; abscisic acid (ABA) and jasmonic acid (JA), which regulate xylem formation; cytokinin (CK), which regulates callus formation, show different accumulation patterns in the incision sites of the ungrafted scion and rootstock. In addition, to try discussing the differences in the degree and speed of each event during the grafting process between intra- and inter-family grafting by determining the concentration and accumulation timing of plant hormones in the graft junctions, we performed hormonome analysis of graft junctions of intra-family grafted plants with N. benthamiana as scion and Solanum lycopersicum as rootstock (Nb/Sl) and inter-family grafted plants with N. benthamiana as scion and Arabidopsis thaliana as rootstock (Nb/At), using the ability of Nicotiana species to graft with many plant species. The results revealed that ABA and CK showed different accumulation timings; IAA, JA, and salicylic acid (SA) showed similar accumulation timings, while different accumulated concentrations in the graft junctions of Nb/Sl and Nb/At. This information is important for understanding the molecular mechanisms of plant hormones in the grafting process and the differences in molecular mechanisms between intra- and inter-family grafting.

Review on toxicology and activity of tomato glycoalkaloids in immature tomatoes

Owing to the lack of selection and limited intelligence in mechanical picking, some immature tomatoes that contain alkaloids are thrown away. Tomatine alkaloids are steroidal alkaloids naturally present in Solanaceae plants, which are distributed in small amounts in immature tomato fruits and decrease as the fruits ripen. Tomato glycoalkaloids are harmful to human health. However, in small quantities, there is some evidence that these compounds might be beneficial, as other non-antioxidant bioactivities. This article considers recent research on the biological effects of tomato glycoalkaloids in immature tomatoes, providing reference value for the potential development of these compounds.

Development of a processing factor prediction model for pesticides in processed tomato foods using elastic net regularization

A novel regularized elastic net regression model was developed to predict processing factor (PF) for pesticide residues, which represents a change in the residue levels during food processing. The PF values for tomato juice, wet pomace and dry pomace in the evaluations and reports published by the Joint FAO/WHO Meeting on Pesticide Residues significantly correlated with the physicochemical properties of pesticides, and subsequently the correlation was observed in the present tomato processing study. The elastic net regression model predicted the PF values using the physicochemical properties as predictor variables for both training and test data within a 2-fold range for 80-100% of the pesticides tested in the tomato processing study while overcoming multicollinearity. These results suggest that the PF values are predictable at a certain degree of accuracy from the unique sets of physicochemical properties of pesticides using the developed model based on a processing study with representative pesticides.

Rapid and sensitive quantitation of amitraz in orange, tomato, and eggplant samples using immunochromatographic assay

Amitraz (AMT) is a broad-spectrum formamidine insecticide and acaricide. In this study, we produced an anti-AMT monoclonal antibody (mAb) with high performance. The half-maximal inhibitory concentration of the anti-AMT mAb was 4.418 ng/mL, the cross reactivity with other insecticides was negligible, and an affinity constant was 2.06 × 109 mmol/L. Additionally, we developed an immunochromatographic assay for the rapid detection of AMT residues in oranges, tomatoes, and eggplants. The cut-off values were 2000 μg/kg in oranges and tomato samples and 1000 μg/kg in eggplant samples and the calculated limits of detection were 14.521 μg/kg, 6.281 μg/kg, and 3.518 μg/kg in oranges, tomatoes, and eggplants, respectively, meeting the detection requirements for AMT in fruits and vegetables. The recovery rates ranged between 95.8 % and 105.2 %, consistent with the recovery rates obtained via LC-MS/MS. Our developed immunochromatographic assay can effectively, accurately, and rapidly determine AMT residues in oranges, tomatoes, and eggplants.

Quantifying terpenes in tomato leaf extracts from different species using gas chromatography-mass spectrometry (GC-MS)

Terpenes play a vital role in plant defense; tomato plants produce a diverse range of terpenes within specialized glandular trichomes, influencing interactions with herbivores, predators, and pollinators. This study employed two distinct methods, namely leaf dip and maceration, to extract trichomes from tomato leaves. Terpene quantification was carried out using Gas Chromatography-Mass Spectrometry (GC-MS). The leaf dip method proved effective in selectively targeting trichome content, revealing unique extraction patterns compared to maceration. The GC-MS method demonstrated high linearity, accuracy, sensitivity, and low limits of detection and quantification. Application of the method to different tomato species (Solanum pennellii, Solanum pimpinellifolium, Solanum galapagense, Solanum habrochaites, and Solanum lycopersicum) identified significant variation in terpene content among these species, highlighting the potential of specific accessions for breeding programs. Notably, the terpene α-zingiberene, known for its repellency against whiteflies, was found in high quantities (211.90-9155.13 μg g-1) in Solanum habrochaites accession PI209978. These findings provide valuable insights into terpenoid diversity for plant defense mechanisms, guiding future research on developing pest-resistant tomato cultivars. Additionally, the study underscores the broader applications of terpenes in agriculture.

Biocontrol mechanism of Bacillus siamensis sp. QN2MO-1 against tomato fusarium wilt disease during fruit postharvest and planting

Tomato fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (Fol) is a highly destructive disease, resulting in severe economic losses of global tomato production annually. An eco-friendly alternative to chemical fungicide using biological control agents (BCAs) is urgently needed. Here, Bacillus siamensis QN2MO-1 was isolated from Noli fruit and had a strong antagonistic activity against Fol in vitro and in vivo. Strain QN2MO-1 also exhibited a broad-spectrum antifungal activity against the selected 14 phytopathogenic fungi. The crude protein produced by strain QN2MO-1 could inhibit the spore germination of Fol and destroy the spore structure. It was closely related with the generation of chitinase and β-1,3-glucanase secreted by strain QN2MO-1. In a pot experiment, the application of B. siamensis QN2MO-1 effectively alleviated the yellowing and wilting symptoms of tomato plants. The disease index and incidence rate were decreased by 72.72% and 80.96%, respectively. The rhizospheric soil in tomato plants owed a high abundance of microbial community. Moreover, strain QN2MO-1 also enhanced the plant growth and improved the fruit quality of tomato. Therefore, B. siamensis QN2MO-1 will be explored as a potential biocontrol agent and biofertilizer.

Plant growth-promoting rhizobacteria Pseudomonas aeruginosa HG28-5 improves salt tolerance by regulating Na+/K+ homeostasis and ABA signaling pathway in tomato

Salinity stress badly restricts the growth, yield and quality of vegetable crops. Plant growth-promoting rhizobacteria (PGPR) is a friendly and effective mean to enhance plant growth and salt tolerance. However, information on the regulatory mechanism of PGPR on vegetable crops in response to salt stress is still incomplete. Here, we screened a novel salt-tolerant PGPR strain Pseudomonas aeruginosa HG28-5 by evaluating the tomatoes growth performance, chlorophyll fluorescence index, and relative electrolyte leakage (REL) under normal and salinity conditions. Results showed that HG28-5 colonization improved seedling growth parameters by increasing the plant height (23.7%), stem diameter (14.6%), fresh and dry weight in the shoot (60.3%, 91.1%) and root (70.1%, 92.5%), compared to salt-stressed plants without colonization. Likewise, HG28-5 increased levels of maximum photochemical efficiency of PSII (Fv/Fm) (99.3%), the antioxidant enzyme activities as superoxide dismutase (SOD, 85.5%), peroxidase (POD, 35.2%), catalase (CAT, 20.6%), and reduced the REL (48.2%), MDA content (41.3%) and ROS accumulation in leaves of WT tomatoes under salt stress in comparison with the plants treated with NaCl alone. Importantly, Na+ content of HG28-5 colonized salt-stressed WT plants were decreased by15.5% in the leaves and 26.6% in the roots in the corresponding non-colonized salt-stressed plants, which may be attributed to the higher K+ concentration and SOS1, SOS2, HKT1;2, NHX1 transcript levels in leaves of colonized plants under saline condition. Interestingly, increased abscisic acid (ABA) content and upregulation of ABA pathway genes (ABA synthesis-related genes NCED1, NCED2, NCED4, NECD6 and signal genes ABF4, ABI5, and AREB) were observed in HG28-5 inoculated salt-stressed WT plants. ABA-deficient mutant (not) with NCED1 deficiency abolishes the effect of HG28-5 on alleviating salt stress in tomato, as exhibited by the substantial rise of REL and ROS accumulation and sharp drop of Fv/Fm in the leaves of not mutant plants. Notably, HG28-5 colonization enhances tomatoes fruit yield by 54.9% and 52.4% under normal and saline water irrigation, respectively. Overall, our study shows that HG28-5 colonization can significantly enhance salt tolerance and improved fruit yield by a variety of plant protection mechanism, including reducing oxidative stress, regulating plant growth, Na+/K+ homeostasis and ABA signaling pathways in tomato. The findings not only deepen our understanding of PGPR regulation plant growth and salt tolerance but also allow us to apply HG28-5 as a microbial fertilizer for agricultural production in high-salinity areas.

Distinct tomato yellow leaf curl Chuxiong virus isolated from whiteflies and plants in China and its symptom determinant and suppressor of post-transcriptional gene silencing

A begomovirus isolated from whiteflies (Bemisia tabaci) and tomato, sweet potato in China was found to be representative of a distinct begomovirus species, for which the name tomato yellow leaf curl Chuxiong virus (TYLCCxV) is proposed. The results of genomic identification and sequence comparison showed that TYLCCxV shares the highest complete nucleotide sequence identity (88.3%) with croton yellow vein mosaic virus (CroYVMV), and may have originated from the recombination between synedrella leaf curl virus (SyLCV) and squash leaf curl Yunnan virus (SLCuYV). Agrobacterium-mediated inoculation showed that TYLCCxV is highly infectious for a range of plant species, producing upward leaf curling, leaf crumpling, chlorosis, distortion, and stunt symptoms in Solanum lycopersicum plants. The results of Southern blot indicated that TYLCCxV is capable of efficiently replicating two heterologous betasatellites. The inoculation of PVX::C4 on Nicotiana benthamiana induced upward leaf curling and stem elongation symptoms, suggesting that TYLCCxV C4 functions as a symptom determinant. TYLCCxV V2 is an important virulence factor that induces downward leaf curling symptoms, elicits systemic necrosis, and suppresses local and systemic GFP silencing in co-agroinfiltrated N. benthamiana and transgenic 16c plants. Considering the multifunctional virulence proteins V2 and C4, the possibility of TYLCCxV causing devastating epidemics on tomato in China is discussed.

Uptake of cyclic C6O4 in maize and tomato: Results from a greenhouse study

Cyclic C6O4 (cC6O4, CAS number 1190931-27-1) is a perfluoralkyl ether used as a polymerization aid in the synthesis of fluoropolymers and produced since 2011 as substitute of PFOA. This work reports the first data on bioaccumulation of cC6O4 on terrestrial plants (maize and tomato). In general, the observed accumulation and translocation of cC6O4 in plants is low or negligible. For maize a bioconcentration factor (BCFdw/dw) of about 39 was observed in the root compartment and much lower (BCFdw/dw = 12) in the aboveground tissues. In tomato the observed BCFs are substantially lower, with a maximum of 2.5 in leaves. The differences observed between the uptake and distribution of cC6O4 in maize and tomato plants are probably due to differences in plant physiology (but also in the experimental design of the tests). Maize plants grown at different concentrations in this study did not show relevant differences in term of biomass and growth, while tomato plants exposed to cC6O4 were subject to a delay in the ripening of the fruits (and relative biomass). The overall results are discussed in comparison with literature data available for legacy PFASs but the comparison is difficult due to differences in the experimental design. It is relevant to note that the concentrations tested in this study are significantly higher than expected environmental concentrations.

Effect of ozone sterilization on controlling leaf mildew and gray mold tomato disease in a glasshouse and its influence on other growth parameters

BACKGROUND

In order to explore the effect of ozone sterilization treatment on tomato disease control and increase fruit setting rate, this study took 906 pink fruit tomato as test material, used a small ozone generator to carry out ozone treatment single-factor test, and then selected orthogonal table to guide the ozone treatment combination. The effects of different ozone treatment concentration, ozone treatment duration and ozone treatment times on the growth, disease and fruit setting rate of potted tomato were analyzed.

RESULTS

Different ozone treatment had effects on leaf mildew, gray mold and fruit setting rate of tomato. The influence degree of three factors on leaf mildew, gray mold and fruit setting rate was from large to small, a > b > c, a > c > b, b > a > c. A quadratic regression model was established with the control effect of tomato leaf mildew, gray mold and fruit setting rate as response values, and the optimal parameter combination was determined: The ozone treatment concentration was 0.0465 g kg-1, the ozone treatment time was 30 min, and the ozone treatment times were twice a week. In this case, the control efficiency of tomato leaf mildew was 95.02%, the control effect of gray mold was 99.49%, and the fruit setting rate was 76.5%. The test parameters were accurate and reliable.

CONCLUSION

The ozone sterilization method proposed in this article is safe and green, and can provide theoretical support for the recovery and reconstruction of tomato disease in a glasshouse. © 2024 Society of Chemical Industry.

Assessment of antibiotic-resistant infection risks associated with reclaimed wastewater irrigation in intensive tomato cultivation

Agricultural irrigation using reclaimed urban wastewater (RWW) represents a sustainable practice to meet the ever-increasing water stress in modern societies. However, the occurrence of residual antibiotics and antibiotic resistant bacteria (ARB) in RWW is an important human health concern. This study applied for the first time a novel Simple-Death dose-response model to the field data of Escherichia coli and Pseudomonas spp. collected from three greenhouses for cultivation of tomatoes irrigated with RWW. The model estimates the risk of infection by enteropathogenic E. coli associated with consumption of tomatoes and the risk of eye-infection caused by Pseudomonas aeruginosa in cultivation soil through hand-to-eye contacts. The fraction of antibiotic resistant (AR)-E. coli measured in irrigation water and AR-Pseudomonas spp. in soil was incorporated in the model to estimate the survival of ARB and antibiotic susceptible bacteria in the presence of trace level of antibiotics in human body. The results showed that the risk of E. coli infection through consumption of tomatoes irrigated with RWW is within the WHO and USEPA recommended risk threshold (<10-4); Pseudomonas aeruginosa eye-infection risk is at or below the acceptable risk level. The presence of residual antibiotic in human body reduced the overall risk probabilities of infections but selectively enhanced the survival of ARB in comparison to their susceptible counterparts, which resulted in antibiotic untreatable infection. Therefore, the outcomes of this study call for a new risk threshold for antibiotic untreatable infections and highlight the key importance of adopting work safety measures for better human health protection.

Metabolism of phenolic compounds catalyzed by Tomato CYP736A61

Cytochrome P450s (CYPs) regulate plant growth and stress responses by producing diverse primary and secondary metabolites. However, the function of many plant CYPs remains unknown because, despite their structural similarity, predicting the enzymatic activity of CYPs is difficult. In this study, one member of the CYP736A subfamily (CYP736A61) from tomatoes was isolated and characterized its enzymatic functions. CYP736A61 was successfully expressed in Escherichia coli through co-expression with molecular chaperones. The purified CYP736A61 showed hydroxylation activity toward 7-ethoxycoumarin, producing 7-hydroxycoumarin or 3-hydroxy 7-ethoxycoumarin. Further substrate screening revealed that dihydrochalcone and stilbene derivates (resveratrol and polydatin) are the substrates of CYP736A61. CYP736A61 also mediated the hydroxylation of resveratrol and polydatin, albeit with low activity. Importantly, CYP736A61 mediated the cleavage of resveratrol and polydatin as well as pinostilbene and pterostilbene. Interestingly, CY736A61 also converted phloretin to naringenin chalcone. These results suggest that CYP736A61 is a novel CYP enzyme with stilbene cleavage activity.

Green-fabricated silver nanoparticles from Quercus incana leaf extract to control the early blight of tomatoes caused by Alternaria solani

BACKGROUND

Early blight (EB) of Tomatoes, caused by Alternaria solani, is a serious fungal disease that adversely affects tomato production. Infection is characterized by dark lesions on leaves, stems, and fruits. Several agrochemicals can be used to control infection, these chemicals may disrupt environmental equilibrium. An alternative technology is needed to address this significant fungal threat. This study was designed to control the growth of EB in tomatoes caused by A. solani, using green-fabricated silver nanoparticles (Ag-NPs).

RESULTS

Ag-NPs were synthesized through an environmentally friendly and cost-effective approach using leaf extract of Quercus incana Roxb. (Fagaceae). The physico-chemical characterization of the Ag-NPs was conducted through UV-visible spectroscopy, scanning electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectrometry. The Ag-NPs produced were round with a mean diameter of 27 nm. The antifungal activity of these Ag-NPs was assessed through in vitro Petri plate and in vitro leaflet assays against A. solani. The green fabricated Ag-NPs exhibited excellent antifungal activity in vitro at a concentration of 100 mg/l against A. solani, inhibiting growth by 98.27 ± 1.58% and 92.79 ± 1.33% during Petri plate and leaflet assays, respectively.

CONCLUSION

In conclusion, this study suggests the practical application of green-fabricated Ag-NPs from Q. incana leaf extract against A. solani to effectively control EB disease in tomatoes.

A novel fluorescent probe with a large Stokes shift for colorimetric and selective detection of cysteine in water, milk, cucumber, pear and tomato

Cysteine is an important amino acid that is related to human health and food safety. How to effectively detect Cys in food has received widespread attention. Compared with other methods, fluorescent probes have the advantages of simple operation, high sensitivity, and good selectivity. Therefore, a selective fluorescence probe 2 for Cys in food was designed and synthesized. Probe 2 employed the acrylate group as a thiol-recognition site for Cys, which endowed probe 2 with better selectivity for Cys over Hcy and GSH. The recognition pathway underwent Michael addition, intramolecular cyclization, and concomitant release of the piperideine-based fluorophore, along with a chromogenic change from yellow to orange. This pathway was supported by 1H NMR analysis and DFT calculations. In addition, probe 2 displays a linear response to Cys concentrations (0-30 μM), low detection limit (0.89 μM), and large Stokes shift (125 nm). Overall, probe 2 showed great application potential for the quantitative determination of Cys in water, milk, cucumber, pear and tomato.

Triazole resistance in Aspergillus fumigatus isolated from a tomato production environment exposed to propiconazole

The emergence of azole-resistant Aspergillus fumigatus (ARAf) across the world is an important public health concern. We sought to determine if propiconazole, a demethylase inhibitor (DMI) fungicide, exerted a selective pressure for ARAf in a tomato production environment following multiple exposures to the fungicide. A tomato field trial was established in 2019 and propiconazole was applied weekly until harvest. Soil, leaf, and fruit (when present) samples were collected at baseline and after each propiconazole application. A. fumigatus isolates (n, 178) were recovered and 173 were tested for susceptibility to itraconazole, posaconazole, voriconazole, and propiconazole in accordance with CLSI M38 guidelines. All the isolates were susceptible to medical triazoles and the propiconazole MIC ranged from 0.25 to 8 mg/L. A linear regression model was fitted that showed no longitudinal increment in the log2-fold azole MIC of the isolates collected after each propiconazole exposure compared to the baseline isolates. AsperGenius real-time multiplex assay ruled out TR34/L98H and TR46/Y121F/T289A cyp51A resistance markers in these isolates. Sequencing of a subset of isolates (n, 46) demonstrated widespread presence of F46Y/M172V/E427K and F46Y/M172V/N248T/D255E/E427K cyp51A mutations previously associated with reduced susceptibility to triazoles.

IMPORTANCE

The agricultural use of azole fungicides to control plant diseases has been implicated as a major contributor to ARAf infections in humans. Our study did not reveal imposition of selection pressure for ARAf in a vegetable production system. However, more surveillance studies for ARAf in food crop production and other environments are warranted in understanding this public and One Health issue.

Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste

The current effort to valorize waste byproducts to increase sustainability and reduce agricultural loss has stimulated interest in potential utilization of waste components as health-promoting supplements. Tomato seeds are often discarded in tomato pomace, a byproduct of tomato processing, yet these seeds are known to contain an array of compounds with biological activity and prebiotic potential. Here, extract from tomato seeds (TSE), acquired from pomace, was evaluated for their ability to effect changes on the gut microbiota using an ex vivo strategy. The results found that TSE significantly increased levels of the beneficial taxa Bifidobacteriaceae in a donor-independent manner, from a range of 18.6-24.0% to 27.0-51.6% relative abundance following treatment, yet the specific strain of Bifidobacteriaceae enhanced was inter-individually variable. These structural changes corresponded with a significant increase in total short-chain fatty acids, specifically acetate and propionate, from an average of 13.3 to 22.8 mmol/L and 4.6 to 7.4 mmol/L, respectively. Together, these results demonstrated that TSE has prebiotic potential by shaping the gut microbiota in a donor-independent manner that may be beneficial to human health. These findings provide a novel application for TSE harvested from tomato pomace and demonstrate the potential to further valorize tomato waste products.

Bacillus methylotrophicus DCS1: Production of Different Lipopeptide Families, In Vitro Antifungal Activity and Suppression of Fusarium Wilt in Tomato Plants

The present work aims to quantitatively and qualitatively monitor the production of lipopeptide mixtures by Bacillus methylotrophicus DCS1 strain in Landy medium and to investigate the antifungal activities of DCS1 strain and its produced lipopeptides. The in vitro activities were tested by the direct confrontation and agar well diffusion methods, while the in vivo study was carried out in order to test the efficiency of DCS1 bacterial suspension in the control of Fusarium wilt in tomato plants. Identification of lipopeptides by mass spectrometry (LC/MSD-TOF) showed that lipopeptide isoforms produced during the first 24 h and 48 h of fermentation are identical, belonging to bacillomycin D and fengycins A and B homologues with a difference in the yield of production. After 72 h of fermentation corresponding to the end of incubation period, B. methylotrophicus DCS1 is able to produce a mixture of surfactin, pumilacidin, iturin A/mycosubtilin, iturin C1, bacillomycin D and fengycins A and B isoforms. The results of in vitro antifungal experiments suggest that B. methylotrophicus DCS1 has a significant potential as a biocontrol agent, owing to lipopeptides produced, endowed with antifungal activity against several phytopathogenic fungi. The curative treatment of tomato plants with DCS1 bacterial suspension was more effective in the protection against Fusarium oxysporum f. sp. radicis-lycopersici (FORL) than the preventive treatment by comparing the average number of leaves remaining healthy after 30 days of each treatment and the appearance of tomato plants roots. The results indicate that B. methylotrophicus DCS1 exhibit a significant suppression of Fusarium wilt symptoms in tomato plants comparable to that of commercial fungicides and could be an alternative to chemically synthesized pesticides.

A new edible coating of fish gelatin incorporated into açaí oil to increase the post-harvest shelf life of tomatoes

Açaí oil (Euterpe oleracea) is a new active ingredient, originating from the Amazon Forest, which offers numerous benefits as an antioxidant and antimicrobial agent. Here, we report how açaí oil can be used as an active ingredient in gelatin coatings to increase the shelf life of tomatoes. The optimized viscosity and gel strength conditions were 5.40 % gelatin, 17.25 % açaí oil and 18 % plasticizer. FTIR, XRD and zeta potential analysis reveals that repulsive forces dominate the interactions between açaí oil and gelatin. The optimized coating (GAO) reduced mass loss by 8 % and achieved greater firmness (25 N), proving its effectiveness in maintaining tomato quality during storage. For the first time, it was found that the addition of açaí oil to fish gelatin improves the percentage of acidity and firmness of the tomato, delaying ripening, making it a promising alternative as packaging for climacteric fruits.

Phytochemical investigation and antioxidant properties of unripe tomato cultivars (Solanum lycopersicum L.)

Unripe tomatoes are among the main waste produced during tomato cultivation and processing. In this study, unripe tomatoes from seven different Italian cultivars have been investigated to evaluate their nutraceutical potential. Phytochemical investigation allowed shedding light on the identification of seventy-five bioactive compounds. The highest amount of polyphenolic and glycoalkaloids along with the high level of antioxidant activities was found in the Datterini tomatoes variety. The peculiarity of this variety is the high chlorogenic acid content, being ten times higher compared to the other cultivars examined. Moreover, the total α-tomatine amount has been found substantially higher (34.699 ± 1.101 mg/g dry weight) with respect to the other tomato varieties analyzed. Furthermore, the cultivars metabolomic profiles were investigated with the PCA approach. Based on Datterini cultivar's metabolomic profile, its waste-recovery could represent a good option for further added value products in pharmaceutical and nutraceutical areas with a high α-tomatine content.

Soil Cd increased the leaf litter Cd remains of Solanum nigrum and Solanum lycopersicum

Plant litter decomposition is a natural pathway of heavy metal cycling in soil ecosystems, but the dynamics of heavy metal release during litter decomposition are relatively poorly understood. The purpose of this study was to investigate the effects of species, soil fauna and soil Cd addition on litter decomposition and Cd release dynamics. Therefore, we selected two plants, Solanum nigrum and S. lycopersicum with large differences in Cd accumulation capacity. First, they were enriched with Cd during the growing period and leaf litter was harvested after 6 months of pretreatment. Then, the decomposition of leaf litter was conducted with or without soil Cd and Eisenia fetida through lab pot tests. Our results showed that leaf litter Cd led to a significant decrease in litter decomposition rate (K value), with a maximum decrease of 32.1% in S. nigrum and 30.1% in S. lycopersicum. We observed that the presence of E. fetida significantly increased K value, but the effect was similar in the +leaf Cd treatment and the -leaf Cd treatment, both for S. nigrum and S. lycopersicum. Interestingly, the litter Cd concentration did not decrease during decomposition, but showed an increasing trend, especially for S. nigrum in the +soil Cd treatment. Moreover, the litter Cd remains was higher in the +soil Cd treatment compared to the -soil Cd treatment for both S. nigrum and S. lycopersicum, no matter whether with or without E. fetida. This result suggests that the Cd may be transferred from soil to litter, thus increasing the litter Cd remains. Overall, our study shows that leaf litter Cd slowed down the carbon cycling in ecosystems. In addition, the release of litter Cd has a lag, and the litter has a certain adsorption capacity for soil Cd, which intensifies the harm to the ecology during litter transfer.

Phthalate ester levels in agricultural soils of greenhouses, their potential sources, the role of plastic cover material, and dietary exposure calculated from modeled concentrations in tomato

Soil samples collected from 50 greenhouses (GHs) cultivated with tomatoes (plastic-covered:24, glass-covered:26), 5 open-area tomato growing farmlands, and 5 non-agricultural areas were analyzed in summer and winter seasons for 13 PAEs. The total concentrations (Σ13PAEs) in the GHs ranged from 212 to 2484 ng/g, wheeas the concentrations in open-area farm soils were between 240 and 1248 ng/g. Σ13PAE in non-agricultural areas was lower (35.0 - 585 ng/g). PAE exposure through the ingestion of tomatoes cultivated in GH soils and associated risks were estimated with Monte Carlo simulations after calculating the PAE concentrations in tomatoes using a partition-limited model. DEHP was estimated to have the highest concentrations in the tomatoes grown in both types of GHs. The mean carcinogenic risk caused by DEHP for tomato grown in plastic-covered GHs, glass-covered GHs, and open-area soils were 2.4 × 10-5, 1.7 × 10-5 and 1.1 × 10-5, respectively. Based on Positive Matrix Factorization results, plastic material usage in GHs (including plastic cover material source for plastic-GHs) was found to be the highest contributing source in both types of GHs. Microplastic analysis indicated that the ropes and irrigation pipes inside the GHs are important sources of PAE pollution. Pesticide application is the second highest contributing source.

Tomato and lemon extracts synergistically improve cognitive function by increasing brain-derived neurotrophic factor levels in aged mice

Brain ageing, the primary risk factor for cognitive impairment, occurs because of the accumulation of age-related neuropathologies. Identifying effective nutrients that increase cognitive function may help maintain brain health. Tomatoes and lemons have various bioactive functions and exert protective effects against oxidative stress, ageing and cancer. Moreover, they have been shown to enhance cognitive function. In the present study, we aimed to investigate the effects of tomato and lemon ethanolic extracts (TEE and LEE, respectively) and their possible synergistic effects on the enhancement of cognitive function and neurogenesis in aged mice. The molecular mechanisms underlying the synergistic effect of TEE and LEE were investigated. For the in vivo experiment, TEE, LEE or their mixture was orally administered to 12-month-old mice for 9 weeks. A single administration of either TEE or LEE improved cognitive function and neurogenesis in aged mice to some extent, as determined using the novel object recognition test and doublecortin immunohistochemical staining, respectively. However, a significant enhancement of cognitive function and neurogenesis in aged mice was observed after the administration of the TEE + LEE mixture, which had a synergistic effect. N-methyl-d-aspartate receptor 2B, postsynaptic density protein 95, and brain-derived neurotrophic factor (BDNF) levels and tropomyosin receptor kinase B (TrkB)/extracellular signal-regulated kinase (ERK) phosphorylation also synergistically increased after the administration of the mixture compared with those in the individual treatments. In conclusion, compared with their separate treatments, treatment with the TEE + LEE mixture synergistically improved the cognitive function, neurogenesis and synaptic plasticity in aged mice via the BDNF/TrkB/ERK signalling pathway.

A Targeted and an Untargeted Metabolomics Approach to Study the Phytochemicals of Tomato Cultivars Grown Under Different Salinity Conditions

In this study, we evaluated the effect of increasing the salinity of irrigation water on the metabolic content and profiles of two tomato cultivars ('Jaune Flamme' (JF) and 'Red Pear' (RP)) using targeted and untargeted metabolomics approaches. Irrigation of tomato plants was performed with four different salt concentrations provided by chloride (treatment 1) and sulfate (treatment 2) salts. Targeted analysis of the methanolic extract resulted in the identification of nine major polyphenols. Among them, chlorogenic acid, rutin, and naringenin were the prominent compounds in both cultivars. In addition, the quantification of 18 free amino acids from both tomato cultivars showed that different salinity treatments significantly enhanced the levels of glutamine, glutamic acid, and γ-aminobutyric acid (GABA). Using the untargeted metabolomic approach, we identified 129 putative metabolites encompassing a diverse array of phytochemicals including polyphenols, organic acids, lipids, sugars, and amino acids. Principal component analysis (PCA) of mass spectral data acquired under positive and negative ionization modes showed a clear separation between the two cultivars. However, only positive ionization showed separation among different salinity treatments. Unsupervised and supervised learning algorithms were applied to mine the generated data and to pinpoint metabolites different from the two cultivars. These findings suggest that different salinity conditions significantly influenced the accumulation of phytochemicals in tomato cultivars. This study will help tomato breeding programs to develop value-added tomato cultivars under varying environmental conditions.

Bacterial biota associated with the invasive insect pest Tuta absoluta (Meyrick)

Tuta absoluta (the tomato pinworm) is an invasive insect pest with a highly damaging effect on tomatoes causing between 80 and 100% yield losses if left uncontrolled. Resistance to chemical pesticides have been reported in some T. absoluta populations. Insect microbiome plays an important role in the behavior, physiology, and survivability of their host. In a bid to explore and develop an alternative control method, the associated microbiome of this insect was studied. In this study, we unraveled the bacterial biota of T. absoluta larvae and adults by sequencing and analyzing the 16S rRNA V3-V4 gene regions using Illumina NovaSeq PE250. Out of 2,092,015 amplicon sequence variants (ASVs) recovered from 30 samples (15 larvae and 15 adults), 1,268,810 and 823,205 ASVs were obtained from the larvae and adults, respectively. A total of 433 bacterial genera were shared between the adults and larval samples while 264 and 139 genera were unique to the larvae and adults, respectively. Amplicon metagenomic analyses of the sequences showed the dominance of the phylum Proteobacteria in the adult samples while Firmicutes and Proteobacteria dominated in the larval samples. Linear discriminant analysis effect size (LEfSe) comparison revealed the genera Pseudomonas, Delftia and Ralstonia to be differentially enriched in the adult samples while Enterococcus, Enterobacter, Lactococcus, Klebsiella and Wiessella were differentially abundant in the larvae. The diversity indices showed that the bacterial communities were not different between the insect samples collected from different geographical regions. However, the bacterial communities significantly differed based on the sample type between larvae and adults. A co-occurrence network of significantly correlated taxa revealed a strong interaction between the microbial communities. The functional analysis of the microbiome using FAPROTAX showed that denitrification, arsenite oxidation, methylotrophy and methanotrophy as the active functional groups of the adult and larvae microbiomes. Our results have revealed the core taxonomic, functional, and interacting microbiota of T. absoluta and these indicate that the larvae and adults harbor a similar but transitory set of bacteria. The results provide a novel insight and a basis for exploring microbiome-based biocontrol strategy for this invasive insect pest as well as the ecological significance of some of the identified microbiota is discussed.

Effects of charged polystyrene microplastics on the bioavailability of dufulin in tomato plant

Microplastics (MPs) and pesticides commonly exist in the environment, yet the interactions between them and their subsequent impacts on plants remain poorly understood. Thus, this study aimed to investigate the impacts of differently charged polystyrene (PS) MPs, including PS-COO-, PS and PS-NH3+ MPs, on the fate of 14C-labelled new antiviral pesticide Dufulin (DFL) in a hydroponic tomato system. The results showed that MPs greatly reduced the growth of tomato plants, with suppression of 18.4-30.2%. Compared to the control group, PS-COO-, PS and PS-NH3+ MPs also reduced the bioaccumulation of DFL in whole tomato plants by 40.3%, 34.5%, and 26.1%, respectively. Furthermore, MPs influenced the translocation of DFL in plant tissues, and the values decreased at the rates of 38.7%, 26.5% and 15.7% for PS-COO-, PS and PS-NH3+, respectively. Interestingly, compared to the control group, PS-COO- exhibited a profound inhibitory effect on DFL concentrations in tomatoes, potentially resulting in a lower dietary risk in the hydroponic tomato system. This may be due to the strong adsorption between PS-COO- and DFL, and PS-COO- may also inhibit the growth of tomato plants. Overall, our study could provide valuable insights into the risk assessment of DFL in the presence of MPs in plant systems.

Alleviation potential of green-synthesized selenium nanoparticles for cadmium stress in Solanum lycopersicum L: modulation of secondary metabolites and physiochemical attributes

KEY MESSAGE

Selenium nanoparticles reduce cadmium absorption in tomato roots, mitigating heavy metal effects. SeNPs can efficiently help to enhance growth, yield, and biomolecule markers in cadmium-stressed tomato plants. In the present study, the effects of selenium nanoparticles (SeNPs) were investigated on the tomato plants grown in cadmium-contaminated soil. Nanoparticles were synthesized using water extract of Nigella sativa and were characterized for their size and shape. Two application methods (foliar spray and soil drench) with nanoparticle concentrations of 0, 100, and 300 mg/L were used to observe their effects on cadmium-stressed plants. Growth, yield, biochemical, and stress parameters were studied. Results showed that SeNPs positively affected plant growth, mitigating the negative effects of cadmium stress. Shoot length (SL), root length (RL), number of branches (NB), number of leaves per plant (NL), and leaf area (LA) were significantly reduced by cadmium stress but enhanced by 45, 51, 506, 208, and 82%, respectively, by soil drench treatment of SeNPs. Similarly, SeNPs increased the fruit yield (> 100%) and fruit weight (> 100%), and decreased the days to fruit initiation in tomato plants. Pigments were also positively affected by the SeNPs, particularly in foliar treatment. Lycopene content was also enhanced by the addition of NPs (75%). Furthermore, the addition of SeNPs improved the ascorbic acid, protein, phenolic, flavonoid, and proline contents of the tomato plants under cadmium stress, whereas stress enzymes also showed enhanced activities under cadmium stress. It is concluded from the present study that the addition of selenium nanoparticles enhanced the growth and yield of Cd-stressed plants by reducing the absorption of cadmium and increasing the stress management of plants.

The predatory mite Pronematus ubiquitus curbs Aculops lycopersici damage under greenhouse conditions

BACKGROUND

The tomato russet mite, Aculops lycopersici, is a major worldwide pest infesting tomato crops for which only few control methods are available. At present, no commercialized beneficial organism has proven to be an effective biological control agent of the pest. As there is a strong need to develop alternatives to synthetic insecticides, we assessed the efficacy of an iolinid mite, Pronematus ubiquitus, as a preventive method against A. lycopersici in comparison with a curative treatment in a replicated experiment in the greenhouse.

RESULTS

After pre-establishment of P. ubiquitus supplied with cattail pollen, followed by infestation of A. lycopersici, the predator was able to reduce pest populations by 98% as compared with control plants. Probably due to lack of food and high temperature, the number of P. ubiquitus decreased during the season and so the Eriophyid population rose, along with crop damage. The sulphur treatment could stop the progress of A. lycopersici, but their population levels remained high.

CONCLUSION

Pronematus ubiquitus has great potential to prevent the establishment of the tomato russet mite. Even if a curative treatment affects the pest mite, the use of a preventive method is preferable as such insecticides/acaricides are harmful for beneficials and are applied after symptom appearance, when the pest pressure is already high. Despite the need to optimise management of the predator throughout the season, P. ubiquitus proved to be able to establish successfully on tomato plants. © 2023 Society of Chemical Industry.

Uptake and translocation of brominated flame retardants in tomato plants (Solanum lycopersicum L.): Results from a standard soil-based biotest

The uptake and translocation of four polybrominated diphenyl ethers (PBDEs) and four novel brominated flame retardants (NBFRs) in tomato plants (Solanum lycopersicum L.) were investigated via the RHIZOtest, a standard soil-based biotest, optimized for organic compounds. Tomato plants were exposed to soil samples spiked with 0 (i.e. control), 5.00 or 50.00 ng g-1dw of each compound. Compared of those of the control, exposure to increasing spiking concentrations resulted in average reductions of 13% and 26% (w/w) in tomato plant biomass. Higher concentrations of NBFRs were analyzed both in roots, ranging from 0.23 to 8.01 ng g-1dw for PBDEs and from 1.25 to 18.51 ng g-1dw for NBFRs, and in shoots, ranging from 0.09 to 5.58 ng g-1dw and from 0.47 to 7.78 ng g-1dw for PBDEs and NBFRs, respectively. This corresponded to an average soil uptake of 5% for PBDEs and 9% for NBFRs at the lower soil-spiking level, and 3% for PBDEs and 6% for NBFRs at the higher soil spiking level. Consequently, among both initial spiking levels, the soil-root concentration factor (RCF) values were lower on average for PBDEs (0.13 ± 0.05 g dw soil g-1dw roots) than for NBFRs (0.33 ± 0.16 g dw soil g-1dw roots). Conversely, nondifferent values of the root-shoot transfer factor (TF) were calculated for both PBDEs (0.54 ± 0.13 g dw roots g-1dw shoots) and NBFRs (0.49 ± 0.24 g dw roots g-1dw shoots). The differences and similarities reported in the RCF and TF between and within the two groups of compounds can be explained by their properties. The calculated RCF and TF values of the PBDEs exhibited a decreasing trend as the number of bromine atoms increased. Additionally, a robust negative linear correlation was observed between RCF values and the respective logKow values for the PBDEs, at both soil-spiking levels. The root uptake of NBFRs exhibited a negative correlation with their hydrophobicity; however, this was not observed in the context of root-to-shoot transfer. The presence of a second aromatic ring appears to be the key factor influencing the observed variations in NBFRs, with biphenyl NBFRs (BTBPE and DBDPE) characterized by lower uptake and reduced translocation potential than monophenyl PBEB and HBB. Understanding the transfer of these compounds to crops, especially near plastic recycling waste sites, is crucial for understanding the risks of their potential inclusion in the human food chain.

Untargeted metabolomics reveals PTI-associated metabolites

Plants employ a multilayered immune system to combat pathogens. In one layer, recognition of Pathogen- or Microbe-Associated Molecular Patterns or elicitors, triggers a cascade that leads to defence against the pathogen and Pattern Triggered Immunity. Secondary or specialised metabolites (SMs) are expected to play a role, because they are potentially anti-fungal compounds. Tomato (Solanum lycopersicum) plants inoculated with Alternaria solani s.l. show symptoms of infection after inoculation. Plants inoculated with Alternaria alternata remain symptomless. We hypothesised that pattern-triggered induction of resistance related metabolites in tomato contributes to the resistance against A. alternata. We compared the metabolomic profile (metabolome) of tomato after treatments with A. alternata, A. solani and the fungal elicitor chitin, and identified SMs involved in early defence of tomato plants. We revealed differential metabolome fingerprints. The composition of A. alternata and chitin induced metabolomes show larger overlap with each other than with the A. solani induced metabolome. We identify 65 metabolites possibly associated with PTI in tomato plants, including NAD and trigonelline. We confirm that trigonelline inhibits fungal growth in vitro at physiological concentrations. Thus, a true pattern-triggered, chemical defence is mounted against A. alternata, which contains anti-fungal compounds that could be interesting for crop protection strategies.

Transcriptomic analysis and knockout experiments reveal the role of suhB in the biocontrol effects of Pantoea jilinensis D25 on Botrytis cinerea

Tomato gray mold, caused by Botrytis cinerea, is an important disease in tomato. Pantoea jilinensis D25, isolated form tomato rhizosphere soil, can prevent B. cinerea infection in tomato. To determine the underlying biocontrol mechanism, the transcriptome of P. jilinensis D25 was assessed. Differential expression analysis revealed that 941 genes were upregulated and 997 genes were downregulated. Through transcriptome analysis, the suhB gene was knocked out. ΔPj-suhB exhibited lower swimming motility and colonization abilities than strain D25. After 4 days of co-cultivation, ΔPj-suhB could reduce the colony diameter, mycelial weight, and spore production of B. cinerea with the inhibitory rates of 31.72 %, 39.62 %, and 47.42 %, respectively, compared with control. However, the inhibitory rates of strain D25 were 52.91 %, 60.09 %, and 76.85 %, respectively, compared with control. Strain D25 could significantly downregulate pathogenesis-related genes in B. cinerea, whereas the expression level of these genes in B. cinerea was higher after treatment with ΔPj-suhB than after that with strain D25. In vitro experiments revealed that the lesion area and disease control efficacy were 1.520 and 0.038 cm2 and 68.7 % and 99.0 %, respectively, after ΔPj-suhB and strain D25 treatments. Pot experiments revealed that ΔPj-suhB and strain D25 could prevent tomato plants from B. cinerea infection with the disease reduction rate of 37.5 % and 75.0 %, respectively. Though the activities of defense-related enzymes and expression level of defense related genes in tomato plants were increased under ΔPj-suhB treatment, these effects were higher after strain D25 treatment. Thus, these results demonstrated that suhB was the key gene in strain D25 underlying its biocontrol effect and mobility.

Induction of tomato plant biochemical immune responses by the synthesized zinc oxide nanoparticles against wilt-induced Fusarium oxysporum

The current study used zinc oxide nanoparticles (ZnO-NPs) to protect the tomato plant against Fusarium wilt. Gamma rays were used to synthesize ZnO-NPs, and the designed ZnO-NPs were characterized using high-resolution transmission electron microscopy (HRTEM), scanning electron microscope (SEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), and ultraviolet-visible (UV-Vis.) spectroscopy. We found that the 20 kGy dose is the most effective for ZnO-NPs synthesis, with the highest O.D. = 1.65 (diluted 3 times) at 400 nm. The scale of ZnO-NPs ranged from 10.45 to 75.25 nm with an average diameter of 40.20 nm. The results showed that the designed ZnO-NPs showed promising activity as a potent inducer of plant physiological immunity against Fusarium wilt disease. Likewise, ZnO-NPs significantly reduced the wilt disease symptoms incidence by 28.57% and high protection by 67.99% against F. oxysporum. Additionally, infected tomato plants treated with ZnO-NPs show improved shoot length (44.71%), root length (40.0%), number of leaves (60.0 %), chlorophyll a (36.93%), chlorophyll b (16.46%), and carotenoids (21.87%) versus infected plants. Notably, in the treatment of tomato seedlings, the beneficial effects of ZnO-NPs extended to increase not only in osmolyte contents but also total phenol contents in comparison with control plants. In conclusion, the designed ZnO-NPs can control Fusarium wilt disease and improve and develop biochemical compounds responsible for defense against fusarial infection.

Arbuscular Mycorrhizal Fungi Inducing Tomato Plant Resistance and Its Role in Control of Bemisia tabaci Under Greenhouse Conditions

Arbuscular mycorrhizal fungi (AMF) are one of the environment-friendly organisms that enhance plant performance. AMF affect the herbivorous insect community by indirectly modifying host plant nutrient uptake, growth, and defense, also known as priming. In the current study, under greenhouse conditions, the effects of inoculating tomato seedlings with four species of AMF, i.e., Funneliformis mosseae, Rhizophagus intraradices, Rhizophagus irregularis, and Glomus iranicus, were studied in relation to tomato plant growth parameters, plant defense enzymes, and total phenol content, and additionally, the life table of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) feeding on these plants was determined. The results demonstrated that the growth parameters of tomato plants, including plant height, stem diameter, number of leaves, root volume, leaf surface area, weight of the root, and aerial organs (containing the leaves and stem), were greater and larger in the AMF-inoculated plants compared to the non-inoculated plants. Furthermore, there were higher defense enzyme activities, including peroxidase, phenylalanine ammonia lyase and polyphenol oxidase, and also higher total phenol contents in the AMF-inoculated plants. The whitefly life table characteristics were decreased in the group feeding on the AMF-inoculated plants. All together, the AMF colonization made the tomato plants more resistant against B. tabaci by improving plant growth and increasing defense enzymes. The degree of priming observed here suggests the potential of AMF to have expansive applications, including their implementation in sustainable agriculture.

Inhibition activity of tomato endophyte Bacillus velezensis FQ-G3 against postharvest Botrytis cinerea

Grey mold, caused by Botrytis cinerea, is a widespread and harmful disease of tomato. Biocontrol agents derived from endophytic bacteria are known to hold great potential for inhibition of phytopathogen. We conducted this study to explore the tomato endophytic strains with inhibition activity against B. cinerea. Endophytic strain Bacillus velezensis FQ-G3 exhibited excellent inhibition activity against B. cinerea. Inhibitory effects against B. cinerea were investigated both in vitro and in vivo. The in vitro assays displayed that FQ-G3 could significantly inhibit mycelia growth with inhibition rate of 85.93%, and delay conidia germination of B. cinerea. Tomato fruit inoculated with B. velezensis FQ-G3 revealed lower grey mold during treatment. The antifungal activity was attributed to activation of defense-related enzymes, as evidenced by the higher levels of peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase in tomatoes after inoculation. In addition, scanning electron microscope was applied to elucidate the interaction between endophytes and pathogen, and bacterial colonization and antibiosis appeared to be the underlying mechanisms that FQ-G3 could suppress growth of B. cinerea. Collectively, our present results suggested that FQ-G3 may potentially be useful as a biocontrol agent in postharvest tomatoes.

Systemic resistance induced in tomato plants by Beauveria bassiana-derived proteins against tomato yellow leaf curl virus and aphid Myzus persicae

BACKGROUND

Tomato (Solanum lycopersicum L.) is an economically important vegetable crop around the globe. Tomato yellow leaf curling (TYLC) is the most devastating viral disease posing a serious threat to tomato production throughout the tropical and subtropical world. Induction of microbe-mediated systemic resistance in plants has been of great interest in recent years as a novel microbiological tool in disease and insect pest management. This in-vitro study aimed to determine the effectiveness of different strains (BB252, BB72 and ARSEF-2860) of a hypocreal fungus Beauveria bassiana against TYLCV disease and aphid Myzus persicae. Potted tomato plants exogenously treated with conidial and filtrate suspensions of B. bassiana strains and of their partially purified or purified proteins were exposed to TYLCV inoculum and aphid M. persicae.

RESULTS

Results showed a significant suppression of TYLCV disease severity index by the exogenous application of conidial, filtrate and protein treatments of all B. bassiana strains and this response was directly proportional to the treatment concentration. Similarly, mean fecundity rate of M. persicae was also significantly reduced by the highest concentration of ARSEF-2860-derived elicitor protein PeBb1, followed by the highest concentrations of BB252- and BB72-derived partially purified proteins. Moreover, these B. bassiana-derived proteins also caused a significant upregulation of most of the plant immune marker genes associated with plant defense.

CONCLUSION

Overall, the study findings suggest that these B. bassiana strains and their partially purified or purified elicitor proteins could be effective biological tools for the management of TYLCV and aphid infestation on tomato plants. © 2023 Society of Chemical Industry.

New approaches to dissect leaf hydraulics reveal large gradients in living tissues of tomato leaves

The water status of the living tissue in leaves is critical in determining plant function and global exchange of water and CO2. Despite significant advances in the past two decades, persistent questions remain about the tissue-specific origins of leaf hydraulic properties and their dependence on water status. We use a fluorescent nanoparticle reporter that provides water potential in the mesophyll apoplast adjacent to the epidermis of intact leaves to complement existing methods based on the Scholander Pressure Chamber (SPC). Working in tomato leaves, this approach provides access to the hydraulic conductance of the whole leaf, xylem, and outside-xylem tissues. These measurements show that, as stem water potential decreases, the water potential in the mesophyll apoplast can drop below that assessed with the SPC and can fall significantly below the turgor loss point of the leaf. We find that this drop in potential, dominated by the large loss (10-fold) of hydraulic conductance of the outside-xylem tissue, is not however strong enough to significantly limit transpiration. These observations highlight the need to reassess models of water transfer through the outside-xylem tissues, the potential importance of this tissue in regulating transpiration, and the power of new approaches for probing leaf hydraulics.

Curcumin: An innovative approach for postharvest control of Alternaria alternata induced black rot in cherry tomatoes

Curcumin, a natural bioactive compound derived from Curcuma longa, has been widely recognized for its antifungal properties. In this study, we investigated the effects of curcumin on the phytopathogenic fungus Alternaria alternata and its pathogenicity in cherry tomato fruit. The results demonstrated that curcumin treatment significantly inhibited mycelial growth and spore germination of A. alternata in a dose-dependent manner. Scanning electron microscopy revealed alterations in the morphology of A. alternata mycelia treated with curcumin. Furthermore, curcumin treatment led to an increase in malondialdehyde and hydrogen peroxide contents, indicating cell membrane damage in A. alternata. Moreover, curcumin exhibited a remarkable inhibitory effect on the incidence and lesion diameters of black rot caused by A. alternata in cherry tomato fruit. Gene expression analysis revealed upregulation of defense-related genes (POD, SOD, and CAT) in tomato fruit treated with curcumin. Additionally, curcumin treatment resulted in decreased activity of exocellular pathogenic enzymes (polygalacturonase, pectin lyase, and endo-1,4-β-d-glucanase) in A. alternata. Overall, our findings highlight the potential of curcumin as an effective antifungal agent against A. alternata, providing insights into its inhibitory mechanisms on mycelial growth, spore germination, and pathogenicity in cherry tomato fruit.

Foodborne Pathogen and Microbial Community Differences in Fresh Processing Tomatoes in Xinjiang, China

The microbes on fresh processing tomatoes correlate closely with diseases, preservation, and quality control. Investigation of the microbial communities on processing tomatoes from different production regions may help define microbial specificity, inform disease prevention methods, and improve quality. In this study, surface microbes on processing tomatoes from 10 samples in two primary production areas of southern and northern Xinjiang were investigated by sequencing fungal internal transcribed spacer and bacterial 16S rRNA hypervariable sequences. A total of 133 different fungal and bacterial taxonomies were obtained from processing tomatoes in the two regions, of which 63 genera were predominant. Bacterial and fungal communities differed significantly between southern and northern Xinjiang, and fungal diversity was higher in southern Xinjiang. Alternaria and Cladosporium on processing tomatoes in southern Xinjiang were associated with plant pathogenic risk. The plant pathogenic fungi of processing tomatoes in northern Xinjiang were more abundant in Alternaria and Fusarium. The abundance of Alternaria on processing tomatoes was higher in four regions of northern Xinjiang, indicating that there is a greater risk of plant pathogenicity in these areas. Processing tomatoes in northern and southern Xinjiang contained bacterial genera identified as gut microbes, such as Pantoea, Erwinia, Enterobacter, Enterococcus, and Serratia, indicating the potential risk of contamination of processing tomatoes with foodborne pathogens. This study highlighted the microbial specificity of processing tomatoes in two tomato production regions, providing a basis for further investigation and screening for foodborne pathogenic microorganisms.

A widely targeted metabolite modificomics strategy for modified metabolites identification in tomato

The structural and functional diversity of plant metabolites is largely created via chemical modification of a basic backbone. However, metabolite modifications in plants have still not been thoroughly investigated by metabolomics approaches. In this study, a widely targeted metabolite modificomics (WTMM) strategy was developed based on ultra-high performance liquid chromatography-quadrupole-linear ion trap (UHPLC-Q-Trap) and UHPLC-Q-Exactive-Orbitrap (UHPLC-QE-Orbitrap), which greatly improved the detection sensitivity and the efficiency of identification of modified metabolites. A metabolite modificomics study was carried out using tomato as a model, and over 34,000 signals with MS2 information were obtained from approximately 232 neutral loss transitions. Unbiased metabolite profiling was also performed by utilizing high-resolution mass spectrometry data to annotate a total of 2,118 metabolites with 125 modification types; of these, 165 modified metabolites were identified in this study. Next, the WTMM database was used to assess diseased tomato tissues and 29 biomarkers were analyzed. In summary, the WTMM strategy is not only capable of large-scale detection and quantitative analysis of plant-modified metabolites in plants, but also can be used for plant biomarker development.

Sublethal and Transgenerational Effects of Reduced-Risk Insecticides on Macrolophus basicornis (Hemiptera: Miridae)

Reduced-risk insecticides and mirid predators have been used to control Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in tomato crops. However, even when causing low mortality to the beneficial insects, these products might cause side effects. This study investigated the sublethal and transgenerational effects of buprofezin, cyantraniliprole, and spiromesifen on Macrolophus basicornis (Stal) (Hemiptera: Miridae). After 72 h of exposure of third-instar nymphs and adults to residues on tomato leaves, adult couples were formed and kept in cages with residue-free tomato leaves. The leaves were changed every 48 h and the offspring were assessed in 6 different periods. Body size was assessed by measuring the hind-tibia length of adults (F0) from exposed nymphs and in three different offspring groups. None of the insecticide residues caused a reduction on offspring populations or affected the body size of adults in generation F0. Regardless, buprofezin and spiromesifen reduced the tibia length of adults (F1) from exposed nymphs assayed in the third mating period. Cyantraniliprole did not affect any parameter and could be recommended for control of B. tabaci in association with M. basicornis releases. This study may contribute to future field assays of the compatibility of these insecticides with M. basicornis.

Treatment of tomato paste wastewater by electrochemical and membrane processes: process optimization and cost calculation

This study investigated the treatment of wastewater from tomato paste (TP) production using electrocoagulation (EC) and electrooxidation (EO). The effectiveness of water recovery from the pretreated water was then investigated using the membrane process. For this purpose, the effects of independent control variables, including electrode type (aluminum, iron, graphite, and stainless steel), current density (25-75 A/m2), and electrolysis time (15-120 min) on chemical oxygen demand (COD) and color removal were investigated. The results showed that 81.0% of COD and 100% of the color removal were achieved by EC at a current density of 75 A/m2, a pH of 6.84 and a reaction time of 120 min aluminum electrodes. In comparison, EO with graphite electrodes achieved 55.6% of COD and 100% of the color removal under similar conditions. The operating cost was calculated to be in the range of $0.56-30.62/m3. Overall, the results indicate that EO with graphite electrodes is a promising pretreatment process for the removal of various organics. In the membrane process, NP030, NP010, and NF90 membranes were used at a volume of 250 mL and 5 bar. A significant COD removal rate of 94% was achieved with the membrane. The combination of EC and the membrane process demonstrated the feasibility of water recovery from TP wastewater.

Salicylic acid- and ethylene-dependent effects of the ER stress-inducer tunicamycin on the photosynthetic light reactions in tomato plants

Plant hormones such as ethylene (ET) and salicylic acid (SA) have an elementary role in the regulation of ER stress and unfolded protein response (UPR) in plants via modulating defence responses or inducing oxidative stress. Chloroplasts can be sources and targets of reactive oxygen species (ROS) that affect photosynthetic efficiency, which has not been investigated under tunicamycin (Tm)-induced ER stress. In this study, the direct and indirect effects of Tm on chloroplastic ROS production were first investigated in leaves of wild-type tomato (Solanum lycopersicum L.) plants. Secondly changes in activities of photosystem II and I were analysed under Tm exposure and after application of the chemical chaperone 4-phenylbutyrate (PBA) in different genotypes, focusing on the regulatory role of SA and ET Tm treatments significantly but indirectly induced ROS production in tomato leaves and in parallel it decreased the effective quantum yield of PSII [Y(II)] and PSI [Y(I)], as well as the photochemical quenching coefficient (qP) and the quantum yield of non-photochemical energy dissipation in PSI due to acceptor-side limitation [Y(NA)]. At the same time, Tm increased non-photochemical quenching (NPQ) and cyclic electron flow (CEF) in tomato leaves after 24 h. However, the photosynthetic activity of the SA hydroxylase-overexpressing NahG tomato plants was more severely affected by Tm as compared to wild-type and ET-insensitive Never ripe (Nr) plants. These results suggest the protective role of SA in the regulation of photosynthetic activity contributing to UPR and the survival of plants under ER stress. Interestingly, the activation of photoprotective mechanisms by NPQ was independent of SA but dependent on active ET signalling under ER stress, whereas CEF was reduced by ET due to its higher ratio in Nr plants.

Mechanisms of biochar assisted di-2-ethylhexyl phthalate (DEHP) biodegradation in tomato rhizosphere by metabolic and metagenomic analysis

The intensive accumulation of di-2-ethylhexyl phthalate (DEHP) in agricultural soils has resulted in severe environmental pollution that endangers ecosystem and human health. Biochar is an eco-friendly material that can help in accelerating organic pollutant degradation; nevertheless, its roles in enhancing DEHP removal in rhizosphere remain unclear. This work investigated the impacts of biochar dosage (0%-2.0%) on DEHP degradation performance in tomato rhizosphere by comprehensively exploring the change in DEHP metabolites, bacterial communities and DEHP-degrading genes. Our results showed a significant increase of rhizosphere pH, organic matter and humus by biochar amendment, which achieved a satisfactorily higher DEHP removal efficiency, maximally 77.53% in treatments with 1.0% of biochar. Biochar addition also remarkably changed rhizosphere bacterial communities by enriching some potential DEHP degraders of Nocardioides, Sphingomonas, Bradyrhizobium and Rhodanobacter. The abundance of genes encoding key enzymes (hydrolase, esterase and cytochrome P450) and DEHP-degrading genes (pht3, pht4, pht5, benC-xylZ and benD-xylL) were increased after biochar amendment, leading to the change in DEHP degradation metabolism, primarily from benzoic acid pathway to protocatechuic acid pathway. Our findings evidenced that biochar amendment could accelerate DEHP degradation by altering rhizosphere soil physicochemical variables, bacterial community composition and metabolic genes, providing clues for the mechanisms of biochar-assisted DEHP degradation in organic contaminated farmland soils.

Impact of repeated fumigant applications on soil properties, crop yield, and microbial communities in a plastic-mulched tomato production system

Pre-plant soil fumigation is widely applied to control nematodes, soil-borne fungal pathogens, and weeds in vegetable crops. However, most of the research evaluating the effect of fumigants on crop yield and soil microbial communities has been done on single compounds despite growers mainly applying fumigant combinations. We studied the effect of different fumigant combinations (chloropicrin, 1,3-dichloropropene, and metam potassium) on soil properties, crop yield, and the soil bacterial and fungal microbiome for two consecutive years in a plastic-mulched tomato production system in Florida (United States). While combinations of fumigants did not improve plant productivity more than the individual application of these products, application of fumigants with >60 % chloropicrin did significantly increase yield. Fumigant combinations had no significant effect on bacterial diversity, but fumigants with >35 % chloropicrin reduced soil fungal diversity and induced temporary changes in the soil bacterial and fungal community composition. These changes included short-term increases in the relative abundance of Firmicutes and Ascomycota, as well as decreases in other bacterial and fungal taxa. Repeated fumigation reduced network complexity and the relative abundance of several predicted bacterial functions and fungal guilds, particularly after fumigation and at end of harvest (3-months post fumigation). A structural equation model (SEM) showed fumigants not only directly impact crop yield, but they can also indirectly determine variations in plant productivity through effects on the soil microbiome. Overall, this study increases our understanding of the environmental and agricultural impacts of fumigants in a plastic-mulched tomato production system.

Divergent colonization traits, convergent benefits: different species of arbuscular mycorrhizal fungi alleviate Meloidogyne incognita damage in tomato

Arbuscular mycorrhizal fungi (AMF) can increase plant tolerance and/or resistance to pests such as the root-knot nematode Meloidogyne incognita. However, the ameliorative effects may depend on AMF species. The aim of this work was therefore to evaluate whether four AMF species differentially affect plant performance in response to M. incognita infection. Tomato plants grown in greenhouse conditions were inoculated with four different AMF isolates (Claroideoglomus claroideum, Funneliformis mosseae, Gigaspora margarita, and Rhizophagus intraradices) and infected with 100 second stage juveniles of M. incognita at two different times: simultaneously or 2 weeks after the inoculation with AMF. After 60 days, the number of galls, egg masses, and reproduction factor of the nematodes were assessed along with plant biomass, phosphorus (P), and nitrogen concentrations in roots and shoots and root colonization by AMF. Only the simultaneous nematode inoculation without AMF caused a large reduction in plant shoot biomass, while all AMF species were able to ameliorate this effect and improve plant P uptake. The AMF isolates responded differently to the interaction with nematodes, either increasing the frequency of vesicles (C. claroideum) or reducing the number of arbuscules (F. mosseae and Gi. margarita). AMF inoculation did not decrease galls; however, it reduced the number of egg masses per gall in nematode simultaneous inoculation, except for C. claroideum. This work shows the importance of biotic stress alleviation associated with an improvement in P uptake and mediated by four different AMF species, irrespective of their fungal root colonization levels and specific interactions with the parasite.

Mycorrhizosphere bacteria inhibit chromium uptake and phytotoxicity by regulating proline metabolism, antioxidant defense system, and aquaporin gene expression in tomato

Chromium (Cr) contamination in soil-plant systems poses a pressing environmental challenge due to its detrimental impacts on plant growth and human health. Results exhibited that Cr stress decreased shoot biomass, root biomass, leaf relative water content, and plant height. However, single and co-application of Bacillus subtilis (BS) and arbuscular mycorrhizal fungi (AMF) considerably enhanced shoot biomass (+ 21%), root biomass (+ 2%), leaf relative water content (+ 26%), and plant height (+ 13) under Cr stress. The frequency of mycorrhizal (F) association (+ 5%), mycorrhizal colonization (+ 13%), and abundance of arbuscules (+ 5%) in the non-stressed soil was enhanced when inoculated with combined BS and AMF as compared to Cr-stressed soil. The co-inoculation with BS and AMF considerably enhanced total chlorophyll, carotenoids, and proline content in Cr-stressed plants. Cr-stressed plants resulted in attenuated response in SOD, POD, CAT, and GR activities when inoculated with BS and AMF consortia by altering oxidative stress biomarkers (H2O2 and MDA). In Cr-stressed plants, the combined application of BS and AMF considerably enhanced proline metabolism, for instance, P5CR (+ 17%), P5CS (+ 28%), OAT (- 22%), and ProDH (- 113%) as compared to control. Sole inoculation with AMF downregulated the expression of SIPIP2;1, SIPIP2;5, and SIPIP2;7 in Cr-stressed plants. However, the expression of NCED1 was downregulated with the application of sole AMF. In contrast, the relative expression of Le4 was upregulated in the presence of AMF and BS combination in Cr-stressed plants. Therefore, it is concluded that co-application of BS and AMF enhanced Cr tolerance by enhancing proline metabolism, antioxidant enzymes, and aquaporin gene expression. Future study might concentrate on elucidating the molecular processes behind the synergistic benefits of BS and AMF, as well as affirming their effectiveness in field experiments under a variety of environmental situations. Long-term research on the effect of microbial inoculation on soil health and plant production might also help to design sustainable chromium remediation solutions.

Fumigation alters the manganese-oxidizing microbial communities to enhance soil manganese availability and increase tomato yield

Manganese is one of the essential trace elements for plants to maintain normal life activities. Soil fumigation, while effectively controlling soil-borne diseases, can also improve the cycling of soil nutrient elements. MiSeq amplicon sequencing is used to determine the composition of soil microbial communities, and structural equation modeling and the random forest algorithm are employed to conduct a correlation analysis between key manganese-oxidizing microorganisms and soil manganese availability. This experiment investigated the microbial mechanisms behind the observed increase in available manganese in soil after fumigation. The key findings revealed that Bacillus, GeoBacillus, GraciliBacillus, Chungangia, and Pseudoxanthomonas play crucial roles in influencing the variation in soil available manganese content. Fumigation was found to elevate the abundance of Bacillus. Moreover, laccase activity emerged as another significant factor impacting soil manganese availability, showing an indirect correlation with available manganese content and contributing to 58 % of the observed variation in available manganese content. In summary, alterations in the communities of manganese-oxidizing microorganisms following soil fumigation are pivotal for enhancing soil manganese availability.

A consumer evaluation of salt-reduced tomato soup and vegetable juice made with grape pomace

Obesity and obesity-related illness have become an increasingly prevalent problem and there is a critical need to combat this by reducing sugar, salt, and fat consumption. Due to this concern, the food industry has been developing salt-reduced foods, however, these products need to maintain their sensory appeal and flavors, which has proven to be a challenge. Grape pomace (GP), the solids left after pressing grapes for winemaking and consisting of grape seeds and skins, has been proposed as an environmentally friendly solution that can enhance the acceptability of salt-reduced food products. However, GP is associated with a large number of flavor compounds. As such, the objective of this research is to investigate the acceptability of GP addition in salt-reduced foods. Two trials were conducted using hedonic scales and temporal check-all-that-apply (TCATA) to evaluate tomato soup (n = 88) and vegetable juice (n = 99). Each trial included a control and sample containing grape pomace. The addition of the GP decreased the consumers' overall liking and the liking of the flavor, as well as increasing consumers' perception of saltiness intensity. The samples made with GP were associated with bitterness, sourness, and wine flavor during the TCATA evaluations. The study identified that GP increased saltiness perception, however, it also adds other flavors to the food product, which decreased the acceptability of the food items. PRACTICAL APPLICATION: There is a consumer demand to create salt-reduced foods that do not have altered sensory properties. Furthermore, consumers are interested in sustainable and environmentally friendly ingredients. Grape pomace is a byproduct of the wine industry and has been proposed as an ingredient that can increase the saltiness perception of food products. Grape pomace was added to tomato soup and vegetable juice to evaluate its effect on consumer acceptability and saltiness perception. The grape pomace did increase saltiness perception, but also added bitterness, sourness, and wine flavor to the food products.

Enzymatic treatment to improve permeability and quality of cherry tomatoes for production of dried products

BACKGROUND

Cherry tomatoes are nutritious and favored by consumers. Processing them into dried cherry tomatoes can prolong their storage life and improve their flavor. The pretreatment of tomato pericarp is crucial for the subsequent processing. However, the traditional physical and chemical treatments of tomato pericarp generally cause nutrient loss and environmental pollution.

RESULTS

In this study, a novel enzymatic method for cherry tomatoes was performed using mixed enzymes containing cutinase, cellulase and pectinase. Results showed that the pericarp permeability of cherry tomatoes was effectively improved due to enzymatic treatment. Changes in the microscopic structure and composition of the cuticle were revealed. After treatment with different concentrations of enzymes, cherry tomatoes exhibited higher pericarp permeability and sensory quality to varying degrees. The lycopene content and total polyphenol content significantly increased 2.4- and 1.45-fold, respectively. In addition, the satisfactory effect of the six-time reuse of enzymes on cherry tomatoes could still reach the same level as the initial effect, which effectively reduced the cost of production.

CONCLUSIONS

This study revealed for the first time that a mixed enzymatic treatment consisting of cutinase, pectinase and cellulase could effectively degrade the cuticle, enhance the pericarp permeability and improve the quality of cherry tomatoes, with the advantages of being mildly controllable and environmentally friendly, providing a new strategy for the processing of dried cherry tomatoes. © 2023 Society of Chemical Industry.

Cell-cell communication and initial population composition shape the structure of potato spindle tuber viroid quasispecies

RNA viruses and viroids replicate with high mutation rates, forming quasispecies, population of variants centered around dominant sequences. The mechanisms governing quasispecies remain unclear. Plasmodesmata regulate viroid movement and were hypothesized to impact viroid quasispecies. Here, we sequenced the progeny of potato spindle tuber viroid intermediate (PSTVd-I) strain from mature guard cells lacking plasmodesmal connections and from in vitro-cultivated mesophyll cell protoplasts from systemic leaves of early-infected tomato (Solanum lycopersicum) plants. Remarkably, more variants accumulated in guard cells compared to whole leaves. Similarly, after extended cell culture, we observed more variants in cultivated mesophyll protoplasts. Coinfection and single-cell sequencing experiments demonstrated that the same plant cell can be infected multiple times by the same or different PSTVd sequences. To study the impact of initial population composition on PSTVd-I quasispecies, we conducted coinfections with PSTVd-I and variants. Two inoculum ratios (10:1 or 1:10) established quasispecies with or without PSTVd-I as the master sequence. In the absence of the master sequence, the percentage of novel variants initially increased. Moreover, a 1:1 PSTVd-I/variant RNA ratio resulted in PSTVd-I dominating (>50%), while the variants reached 20%. After PSTVd-I-only infection, the variants reached around 10%, while after variant-only infection, the variants were significantly more than 10%. These results emphasize the role of cell-to-cell communication and initial population composition in shaping PSTVd quasispecies.

Comparative life cycle assessment of environmental impacts and economic feasibility of tomato cultivation systems in northern plains of India

To meet the growing demand for vegetable production and promote sustainable agriculture, it is imperative to implement effective input management and adopt eco-friendly farming practices. This study aims to compare the environmental impacts of conventional and organic tomato cultivation in the northern plains of India. This study utilizes SimaPro 9.1.1 software for a comprehensive cradle-to-farm gate Life Cycle Assessment (LCA), assessing production stages, identifying key environmental factors, and incorporating ReCiPe Midpoint and Endpoint methods with one-hectare as a functional unit. Findings reveal that conventional cultivation is more affected by fertilizer application and transplanting, while organic cultivation emphasizes transplanting and irrigation. Organic cultivation contributes 904.708 kg CO2, while conventional cultivation contributes 1307.917 kg CO2 to Global Warming potential. Switching to organic cultivation leads to a significant 35.04% decrease in all impact categories. Using the endpoint method, organic cultivation achieves a notable 27.16% reduction, scoring 58.30 compared to conventional cultivation's 80.04. The LCA analysis of tomato cultivation highlights Fertilizer application as the predominant environmental concern, emphasizing the need for sustainable techniques to minimize waste and mitigate environmental impacts. This study recommends imposing restrictions on fertilizer and pesticide use and formulating effective policies to promote the adoption of sustainable practices.