•Biostimulant application rate effect on two tomato cultivars was explored.•Application of biostimulant at high dose (5mlL−1) improved marketable yield.•Biostimulant at high dose enhanced ...photosynthesis and leaf nutritional status.•Key quality attributes of fresh tomato were improved by biostimulant application.
The use of natural plant biostimulants is proposed as a promising and innovative approach to ensure improved and sustainable yields and product quality. A greenhouse experiment was performed to assess the yield performance, leaf net assimilation of CO2, mineral composition of leaves and fruits, and fruit physicochemical quality attributes of two tomato cultivars (Akyra and Sir Elyan) in relation to biostimulant treatments (control or two different concentrations of the legume-derived protein hydrolysate Trainer®). Treated tomato plants were sprayed every 10days with a solution containing 2.5 and 5.0mlL−1 of biostimulant. Akyra was found to be richest in K, Ca, Mg, lipophilic and hydrophilic antioxidant activities (LAA and HAA), lycopene, total phenolic and total ascorbic acid. Foliar applications of legume-derived protein hydrolysate at 5.0mlL−1 increased marketable yield of Akyra and Sir Elyan by modulating yield components differently depending on cultivars: higher number of fruits in Akyra and increase of fruit mean weight in Sir Elyan. Improved yield performance with biostimulant foliar applications at the highest rate was related to improved leaf nutritional status (higher K and Mg) and higher net assimilation of CO2. The application of legume-derived protein hydrolysate at 5.0mlL−1, and to a lesser degree at 2.5mlL−1, elicited an increase in antioxidant activities, total soluble solids, mineral composition (K and Mg) as well as bioactive molecules such as lycopene and ascorbic acid, thereby increasing the nutritional and functional quality of the fruits. These findings can assist tomato growers in selecting cultivars and application dose for protein hydrolysate to complement high crop productivity with optimal fruit quality.
We investigated vanillic acid-induced salt tolerance in tomato by exploring the plant defense systems. Ten-d-old tomato (Solanum lycopersicum L. cv. Pusa Ruby) seedlings were treated with salt (NaCl; ...150 mM) and vanillic acid (VA; 40 and 50 μM) separately and in combination with salt. Salinity restricted seedlings growth, biomass accumulation, chlorophyll and carotenoid contents. Salt-induced osmotic stress was indicated by lower leaf relative water content (RWC) and elevated proline (Pro) content, where higher Na+/K+ ratio indicated the ionic toxicity. Tomato seedlings went through oxidative damage due to acute reactive oxygen species (ROS) production and lipoxygenase (LOX) activity and confirmed by higher lipid peroxidation and membrane damage under salinity. Conversely, exogenous VA reduced osmotic and ionic toxicity in stressed-seedlings by enhancing the RWC and Pro level, and lowering Na+/K+ ratio, respectively. Exogenous VA up-regulated the components of antioxidant defense system in salt-treated seedlings resulted in the reduction of ROS production, LOX activity and membrane damage in stressed-seedlings. Additionally, VA application caused the reduction of toxic methylglyoxal accumulation under salt stress through the enhancement of glyoxalase system. Thus, VA-induced alleviation of osmotic, ionic and oxidative stresses leading to improve plant growth and chlorophyll synthesis in stressed-seedlings. So, VA significantly improves salinity tolerance and plant growth performance by involving the actions of plant antioxidant defense and glyoxalase systems.
•Vanillic acid (VA) is able to increase salt tolerance of tomato significantly.•VA increases plant growth, and reduce membrane damage under salt stress.•VA enhances osmotic adjustments and reduce oxidative stress.•VA confers salt stress by enhancing antioxidants and glyoxalase activity.
•SlMYB102, an R2R3-MYB transcription factor, is induced by salt and osmotic stresses.•SlMYB102 increases the salt tolerance of transgenic tomato plants through regulating Na+-K+ homeostasis and ROS ...balance.•The application of this gene in salt tolerance was first discovered.
Salinity threatens the productivity of tomato (Solanum lycopersicum L.). R2R3-type MYB transcription factors are important regulators in response to environmental stress. Here, we analyzed the function of the tomato R2R3-type MYB gene SlMYB102. A transcriptional activation assay showed that SlMYB102 had transactivation activity in yeast. Promoter analysis showed that multiple stress-related elements were found in the promoter of SlMYB102. Furthermore, SlMYB102 was induced by osmotic stress, particularly by salt stress. The overexpression of SlMYB102 in tomato affected multiple parameters under salinity stress. Under long-term salt stress, the degree of growth inhibition was significantly reduced in the two overexpression (OE) lines. In addition, the two OE lines maintained a better K+/Na+ ratio, lower reactive oxygen species (ROS) generation (O2•− production rate and H2O2 content) and lower electrolytic leakage rates than the wild type (WT). The activity of ROS scavenging enzymes including superoxide dismutase, peroxidase, catalase and ascorbate peroxidase, and the accumulation of antioxidants (ascorbic acid and glutathione) and proline was higher in the two OE lines compared with WT. The qRT-PCR analysis confirmed that the transcript abundance of many salt stress-related genes (SlSOS1, SlSOS2, SlNHX3, SlNHX4, SlHAK5, SlCPK1 and SlCPK3) was upregulated in two OE lines under salt stress. Collectively, these results suggest that SlMYB102 participates in tomato tolerance through the regulation of a series of molecular and physiological processes.
•Se-biofortification and grafting improved plant vigour, yield and fruit quality.•Se-biofortification and grafting enhanced nitrogen use efficiency (NUE).•Se biofortification × grafting interaction ...improved Se concentration in fruits.
Selenium (Se) is an essential trace element for humans due to its importance in a number of enzymes. Vegetable grafting is a valuable tool to overcome biotic and/or abiotic issues and to increase vigour, yield traits and fruit quality. The present work aimed at testing both different Se concentrations (0.0, 1.0, 2.0 and 4.0 μmol Se L−1) supplied via fertigation and grafting on cherry tomato in soilless culture. Se at 2.0 μmol L−1 improved total fruit yield by 60.0 % and 31.4 % in ungrafted and grafted plants, respectively as compared to the control. Marketable yield was positively affected by Se-biofortification and grafting. Se at 2.0 μmol L−1 improved N use efficiency by 60.3 % and 31.5 % in ungrafted and grafted plants, respectively. Furthermore, Se at 4.0 μmol L−1 and grafting enhanced fruit firmness, SSC, polyphenol content and total carotenoids. Ascorbic acid and lycopene were enhanced by Se-doses and grafting. Fruit Se concentration in ungrafted plants varied from 0.1 mg kg−1 of dry weight (DW) in the control to 8.9 mg kg−1 DW in plants treated with 4.0 μmol Se L−1. Se fruits concentration in grafted plants ranged from 0.08 in the control to 9.8 mg kg−1 DW in plants treated at 4.0 μmol L−1. Non-grafted and grafted plants manifested an increment in the hazard quotient (HQgv) in reaction to Se. HQgv fluctuated from 0.002 to 0.353, with a daily intake for Se below the recommended value. Finally, Se-biofortification (at 2.0 or 4.0 μmol L−1) and grafting succeeded in improving tomato plant performance, nutritional and health-promoting compounds.
Despite our understanding of plant responses to single stresses, knowledge on how plants respond to combined abiotic factors and the underlying hormonal regulation is still very limited. Here, we ...aimed to examine the plant response to combined heat and salt stresses in tomato plants, the underlying hormonal response and the effectiveness of methyl jasmonate application in its alleviation. We measured fruit production and various stress markers in both roots and leaves, together with endogenous contents of stress-related phytohormones (including abscisic acid, salicylic acid and jasmonates) in tomato plants (Solanum lycopersicum cv. Micro-Tom), exposed to combined stress. In addition, we evaluated the effectiveness of a methyl jasmonate treatment as a priming agent to alleviate the negative effects of stress, with an emphasis on evaluating the effects of this hormone on triggering antioxidant protection by enhancement of vitamin E contents. Plants responded differently to combined stress treatment than to single stresses, but this differential response was organ-specific, with roots being more sensitive to stress than leaves. Both abscisic acid and jasmonates were involved in the plant response to combined stress but leaves and roots responded differently. Furthermore, abscisic acid and jasmonates correlated with vitamin E accumulation, most particularly in roots. Foliar application of methyl jasmonate at the flowering stage in plants challenged with combined stress did not improve fruit production but resulted in enhanced vitamin E accumulation in leaves. It is concluded that (i) roots and leaves show a differential sensitivity to both single and combined heat and salt stresses, (ii) the response of abscisic acid and jasmonates in plant stress responses seems to be markedly organ dependent, and (iii) foliar methyl jasmonate increased vitamin E accumulation under combined stress in tomato plants.
•Roots were more sensitive to both single and combined abiotic stress than leaves.•Both abscisic acid and jasmonates modulated the plant response to combined stress, but leaves and roots responded differently.•Abscisic acid and jasmonates positively correlated with vitamin E accumulation, most particularly in roots.•Foliar application of methyl jasmonate at the flowering stage did not alleviate reductions in fruit production in plants challenged with combined stress.
Intercropping with hyperaccumulators can facilitate the safe utilization of cadmium-contaminated soil. However, the effectiveness of this approach is influenced by plant species and varieties, which ...necessitates research on optimal plant consortia. In this study, 8 tomato varieties (3 cherry tomatoes and 5 common large-fruit tomatoes) were intercropped with Sedum alfredii in a moderately Cd-contaminated vegetable field. The results showed that the Cd concentration in the fruits of common large-fruit tomato varieties under monoculture was 1.03–1.50 mg/kg, while that in the fruits of cherry tomato varieties was 0.67–0.71 mg/kg. After intercropping with S. alfredii, the fruit Cd concentrations of Hangza 501, Hangza 503, and Hangza 108 decreased by 16.42 %, 19.72 %, and 6.76 %, respectively, while those of the other varieties significantly increased, except for those of Hangza 8. In contrast, the shoot Cd concentration of cherry tomatoes was greater than that of large-fruit tomatoes under monoculture. Furthermore, a significant increase in the shoot Cd concentration was noted in the Hangza 501, Hangza 503 and Hangza 603 plants following intercropping. Additionally, intercropping with S. alfredii increased the concentration of soluble sugars in the fruits of Hangza 8, Hangza 501, Hangza 503 and Hangza 603 by 4.66 %, 17.91 %, 10.60 % and 17.88 %, respectively. Intercropping with tomatoes resulted in a decrease in both the biomass and Cd uptake of S. alfredii. Interestingly, the inhibitory effect on S. alfredii was less pronounced when intercropped with cherry tomatoes than when intercropped with large-fruit tomatoes. Among the intercropping treatments, S. alfredii exhibited the greatest total Cd accumulation (0.06 mg/plant) when intercropped with Hangza 503. In conclusion, the cherry tomato variety Hangza 503 was the most suitable for intercropping with S. alfredii and can be used safely for vegetable production and simultaneous phytoremediation of polluted soil. Our findings suggest that strategic selection of tomato varieties can optimize the effectiveness of “phytoextraction coupled with agro-safe production” technology for managing soil Cd concentrations.
Display omitted
•Cherry tomatoes have notably lower fruit Cd concentration than common large fruit tomatoes.•Intercropping with S. alfredii reduced the fruit Cd concentration of cherry tomatoes.•Inhibition of cherry tomatoes on Cd uptake of S. alfredii is lower than that of large fruit tomatoes.•Cherry tomato Hangza 503 found well-adapted for both monoculture and intercropping with S. alfredii.
•Seed priming with ACC deaminase producing B. subtilis Rhizo SF 48 induced resistance against drought stress in tomato plants.•B. subtilis Rhizo SF 48 enhanced the plant growth parameters in tomato ...plants subjected to drought stress.•Antioxidant machinery played a vital role in tomato plants treated with Rhizo SF 48 for the induction of drought tolerance.•Downregulation of Le25 and SlERF84 confirm the positive effect of Rhizo SF 48 in tomato plants subjected to drought stress.
A total of ten 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing PGPR isolates were selected and evaluated for the induction of drought stress tolerance in tomato. Among the selected PGPR, maximum seed (laboratory) and plant growth promotion (greenhouse) was observed in tomato seeds bacterized with Bacillus subtilis Rhizo SF 48. The genomic study confirmed the presence of ACC deaminase gene in Rhizo SF 48 and the obtained sequence was deposited to the NCBI database with the Accession No. MK652706. The tomato plants grown upon treatment with Rhizo SF 48 significantly enhanced plant growth even after exposing to different levels of drought stress as compared to stress induced control plants. About 7.5% and 38% increase in RWC were observed in Rhizo SF 48 treated tomato plants grown under well-watered and stress conditions (S4) compared to their control plants, respectively. An increase of 0.76, 0.23 and 0.78 fold in proline, SOD and APX activity and a decrease of 0.3 fold in MDA and H2O2 contents were observed in Rhizo SF 48 treated plants compared to control plants grown under S4 conditions. The histo-chemical studies showed lower accumulations of H2O2 and superoxide anion in the leaves of Rhizo SF 48 treated plants under drought stress, which was in confirmation with the quantification results of H2O2 and SOD. The qRT-PCR studies on drought (Le25) and ethylene responsive factor (SlERF84) marker genes showed that a significant decrease of 0.75 and 0.81 folds, respectively in Le25 and SlERF84 accumulation was observed in Rhizo SF 48 treated plants compared to untreated plants grown under S4 conditions. From the results, it can be attributed that ACC deaminase producing Rhizo SF 48 was able to protect tomato plants against oxidative damage caused due to drought stress and enhanced plant growth promotion. It can be concluded that ACC deaminase producing Rhizo SF 48 can serve as a useful bio-inoculant for sustainable tomato production in arid and semi-arid regions with water deficit.
Plants do not always have the genetic capacity to tolerate high levels of arsenic (As), which may not only arrest their growth but pose potential health risks through dietary bioaccumulation. ...Meanwhile, the interplay between the tomato plants and As–NO-driven molecular cell dynamics is obscure. Accordingly, seedlings were treated with As (10 mg/L) alone or in combination with 100 μM sodium nitroprusside (SNP, NO donor) and 200 μM 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO, NO scavenger). Sodium nitroprusside immobilized As in the roots and reduced the shoot translocation by up-regulating the transcriptional expression of the PCS, GSH1, MT2, and ABC1. SNP further restored the growth retardation through modulating the chlorophyll and proline metabolism, increasing NO accumulation and stomatal conductance along with clear crosstalk between the antioxidant activity as well as glyoxalase I and II leading to endogenous H2O2 and MG reduction. Higher PCs and glutathione accumulation helped protect photosynthetic apparatus; however, cPTIO reversed the protective effects of SNP, confirming the role of NO in the As toxicity alleviation.
•SNP blocked As mobility in root and reduced shoot translocation by governing gene transcripts in As-sequestration network.•The expression of PCS, GSH1, MT2 and ABC1 genes were up-regulated in As-stressed tomato.•SNP guided the proline and chlorophyll metabolism thereby improved tomato tolerance under As stress.•SNP decreased the H2O2 and MG genesis by modulating overall anti-oxidant machinery, as well as the glyoxalase I and II.
PDF
