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Chemical fertilizers can improve crop productivity, but irrational fertilization often results in low crop quality and yield, poor soil fertility, and severe environmental pollution. Nevertheless, little research has been conducted with a close focus on the cultivation of radish in high mountain regions, a widely cultivated root vegetable known for its nutritional value and economic importance. Here, a method of reducing chemical fertilizers combined with the application of organic fertilizers is proposed upon studying four different ratios of chemical and organic fertilizers, including control (375 kg·ha−1 chemical fertilizer + 4500 kg·ha−1 organic fertilizer) and combinations (T1: 12% reduction in chemical fertilizer + 4500 kg·ha−1 organic fertilizer; T2: 20% reduction in chemical fertilizer + 4500 kg·ha−1 organic fertilizer; T3: 28% reduction in chemical fertilizer + 4500 kg·ha−1 organic fertilizer). Their effects on radish quality, yield, and soil environment were investigated. Compared with the control group, T2 significantly increased radish yield by 12.92% and improved the contents of vitamin C, soluble sugars, sulforaphane soluble solids, and titratable acidity in the radish roots by 10.62%, 2.15%, 50.00%, 26.90%, and 43.90%, respectively. The soil nutrient content was increased by the T2 treatment, with a 7.69% and 14.29% increase in total nitrogen and total phosphorus content, respectively, compared with the control. Moreover, soil urease activity, sucrase activity, alkaline phosphatase activity, and catalase activity were significantly enhanced by the T2 treatment, showing an improvement of 11.13%, 44.30%, 26.41%, and 9.33% compared with the control, respectively (p < 0.05). The relative abundance of beneficial bacterial phyla such as Proteobacteria and Actinobacteria was increased in the T2 treatment, potentially helping to maintain better soil health and long-term fertility. In summary, a promising fertilizer management strategy is herein unveiled through the reduction of chemical fertilizers and the application of organic fertilizer that not only improves radish yield and quality but also optimizes the soil environment, providing an effective means for sustainable crop production. [ABSTRACT FROM AUTHOR]

Melatonin (MT) plays a number of key roles in regulating plant growth and secondary metabolite accumulation. Prunella vulgaris is an important traditional Chinese herbal medicinal plant which is used for the treatment of lymph, goiter, and mastitis. However, the effect of MT on the yield and medicinal component content of P. vulgaris remains still unclear. In this research, we have examined the influence of different concentrations of MT (0, 50, 100, 200, 400 μM) on the physiological characteristics, secondary metabolite contents, and yield of P. vulgaris biomass. The results showed that 50–200 μM MT treatment had a positive effect on P. vulgaris. MT treatment at 100 μM greatly increased the activities of superoxide dismutase and peroxidase, the contents of soluble sugar and proline, and obviously decreased the relative electrical conductivity, the contents of malondialdehyde and hydrogen peroxide of leaves. Furthermore, it markedly promoted the growth and development of the root system, increased the content of photosynthetic pigments, improved the performance of photosystems I and II and the coordination of both photosystems, and enhanced the photosynthetic capacity of P. vulgaris. In addition, it significantly increased the dry mass of whole plant and spica and promoted the accumulation of total flavonoids, total phenolics, caffeic acid, ferulic acid, rosmarinic acid, and hyperoside in the spica of P. vulgaris. These findings demonstrated that the application of MT could effectively activate the antioxidant defense system of P. vulgaris, protect the photosynthetic apparatus from photooxidation damage, and improve the photosynthetic capacity and the root absorption capacity, thereby promoting the yield and accumulation of secondary metabolites in P. vulgaris. [ABSTRACT FROM AUTHOR]

Brassica vegetables are very important to human beings. Self-incompatibility (SI) is a common phenomenon in Brassica. Breeding by SI lines is an important way to utilize heterosis of Brassica vegetables. It is believed that the SI inheritance in Brassica species is controlled by three linkage genes on the S-locus, including SRK (S-locus receptor kinase), SCR (S-locus cystine-rich protein)/SP11 (S-locus protein 11), and SLG (S-locus glycoprotein). SRK is the female determinant and SCR/SP11 is the pollen S gene. The expression of SLG is necessary for SRK, and it enhances the SRK-mediated SI reaction. In addition to these three S-locus genes, some other functional molecules also have significant regulatory effects on SI, such as ARC1 (arm repeat containing 1), MLPK (M-locus protein kinase), Exo70A1 (exocyst compounds), THLl/THL2 (thioredoxin H-like), MOD (aquaporin), SLR (S-locus-related glycoprotein), BPCI (pollen calcium-binding protein I), etc. SI is also associated with the dominant/recessive relationship between S alleles. Here, the genetic elements and molecular mechanisms of SI, mainly in Brassica vegetables, are reviewed. [ABSTRACT FROM AUTHOR]

Treating and utilizing vegetable residues may reduce waste and improve rhizosphere soil. This study explored the effects of tomato plant residue compost and plant growth-promoting rhizobacteria (PGPR) on the physicochemical properties and microbial community of ginger field soil. Four treatment procedures were adopted: no compost or PGPR (CK), compost (TC), compost + Bacillus subtilis (TC-BS), and compost +Bacillus amyloliquefaciens SQR9 (TC-BA). The results showed that compared with the CK, TC significantly increased soil organic matter, alkali hydrolyzable nitrogen, available phosphorus, and available potassium by 17.34%, 21.66%, 19.56%, and 37.20%, respectively. Soil urease activity, neutral phosphatase activity, and sucrase activity increased by 55.89%, 35.59%, and 57.21%, respectively. Chloroflexi, Gemmatimonadetes, and Bacillus abundances increased by 1.40%, 1.80%, and 0.68%, respectively, while Firmicutes decreased by 0.80%. TC-BS significantly improved soil bacterial diversity than CK and TC, and relative abundance of Beneficial Proteobacteria, Acidobacteria, Chloroflexi, and Bacillus microorganisms dominated. Principal coordinate analysis revealed significant differences in bacterial community structure among different treatments. Redundancy analysis indicated total potassium (p = 0.002), pH (p = 0.0012), and available phosphorus (p = 0.016) as the main community composition driving factors. In conclusion, B. subtilis inoculation in ginger field soil supplemented with tomato compost enhanced bacterial diversity, altered bacterial community structure, enriched beneficial microorganisms, and promoted a healthy rhizosphere. [ABSTRACT FROM AUTHOR]

Heavy metal pollution not only decreases crop yield and quality, but also affects human health via the food chain. Ubiquitination‐dependent protein degradation is involved in plant growth, development, and environmental interaction, but the functions of ubiquitin‐ligase (E3) genes are largely unknown in tomato (Solanum lycopersicum L.). Here, we functionally characterized a RING E3 ligase gene, SlRING1, which positively regulates cadmium (Cd) tolerance in tomato plants. An in vitro ubiquitination experiment shows that SlRING1 has E3 ubiquitin ligase activity. The determination of the subcellular localization reveals that SlRING1 is localized at both the plasma membrane and the nucleus. Overexpression of SlRING1 in tomato increased the chlorophyll content, the net photosynthetic rate, and the maximal photochemical efficiency of photosystem II (Fv/Fm), but reduced the levels of reactive oxygen species and relative electrolyte leakage under Cd stress. Moreover, SlRING1 overexpression increased the transcript levels of CATALASE (CAT), DEHYDROASCORBATE REDUCTASE (DHAR), MONODEHYDROASCORBATE REDUCTASE (MDHAR), GLUTATHIONE (GSH1), and PHYTOCHELATIN SYNTHASE (PCS), which contribute to the antioxidant and detoxification system. Crucially, SlRING1 overexpression also reduced the concentrations of Cd in both shoots and roots. Thus, SlRING1‐overexpression‐induced enhanced tolerance to Cd is ascribed to reduced Cd accumulation and alleviated oxidative stress. Our findings suggest that SlRING1 is a positive regulator of Cd tolerance, which can be a potential breeding target for improving heavy metal tolerance in horticultural crops. [ABSTRACT FROM AUTHOR]

Brassinosteroids (BRs) are a group of plant steroid hormones with multiple roles in plant growth, development, and responses to stresses. In plants, BR deficiencies impair vital physiological processes and cause phenotypic abnormalities. A large number of studies show that BRs can positively influence plant responses to abiotic stresses such as heat, cold, drought, salinity, pesticides, and heavy metals. However, the underlying mechanisms of BR-induced stress tolerance are largely unclear. BR perception takes place in the cell surface by BR receptors, leading to a cascade of phosphorylation events to activate the central transcription factor BRASSINAZOLE-RESISTANT1 (BZR1) that controls the transcription of BR-responsive genes in the nucleus. BRs improve photosynthetic efficiency under stress conditions, which largely contributes to increased growth and biomass accumulation. Studies relating to exogenous BRs reveal a high dependency on concentrations with regards to BR effects on plants. Genetic studies show a positive correlation between the endogenous BR levels and abiotic stress tolerance, although this assumption contradicts with the performance of some BR mutants under stress conditions. Notably, plant responses to BRs greatly vary depending on the plant species, developmental stages, and environmental conditions. In addition, other hormones and signaling molecules that participate in fine-tuning the BRs effects also play an important role in plant adaptation to stress. Here, we review the involvement of BRs in plant responses to abiotic stresses. We also discuss available literature to show potential mechanisms of BR-induced abiotic stress tolerance. These studies signify the complexity of BR action in mediating stress responses in plants. [ABSTRACT FROM AUTHOR]

Salinity is a global environmental problem, restricting crop production in a vast area of agricultural land. Although epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in tea plants, has a strong antioxidative action in vitro, the role of EGCG in the plant response to salt stress remains unknown. In the present study, using a series of EGCG concentrations (10, 100, and 1000 µM), we showed that EGCG could alleviate salt stress-induced inhibition in seed germination and root growth in tomato. Exogenous EGCG increased not only the seed germination rate, but also the germination energy and germination index under salt stress. The 150 mM NaCl treatment significantly increased lipid peroxidation in roots by excessive accumulation of reactive oxygen species (ROS). In contrast, EGCG treatment, particularly at 100 µM concentration, mitigated NaCl-induced oxidative stress as evidenced by the decreased H2O2 and malondialdehyde content in roots. Analysis of the antioxidant enzyme system reveals that EGCG increased the activity of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase under salt stress. Considering the beneficial effect of EGCG on seed germination, root growth, ROS scavenging, and antioxidant enzyme activity, the 100 µM EGCG treatment appears to be the most effective concentration of those tested under salt stress in tomato. Our results suggest that the EGCG-promoted tomato tolerance to salt stress is associated with the mitigation of oxidative stress through an efficient ROS scavenging mechanism by the action of enhanced antioxidant enzyme activity. Thus, the enhancement of plant tolerance by exogenous EGCG can potentially expand crop cultivation in saline soils. [ABSTRACT FROM AUTHOR]

Despite a range of initiatives to reduce global carbon emission, the mean global temperature is increasing due to climate change. Since rising temperatures pose a serious threat of food insecurity, it is important to further explore important biological molecules that can confer thermotolerance to plants. Recently, melatonin has emerged as a universal abiotic stress regulator that can enhance plant tolerance to high temperature. Nonetheless, such regulatory roles of melatonin were unraveled mainly by assessing the effect of exogenous melatonin on plant tolerance to abiotic stress. Here, we generated melatonin deficient tomato plants by silencing of a melatonin biosynthetic gene, CAFFEIC ACID O-METHYLTRANSFERASE 1 (COMT1), to unveil the role of endogenous melatonin in photosynthesis under heat stress. We examined photosynthetic pigment content, leaf gas exchange, and a range of chlorophyll fluorescence parameters. The results showed that silencing of COMT1 aggravated heat stress by inhibiting both the light reactions and the carbon fixation reactions of photosynthesis. The photosynthetic pigment content, light absorption flux, trapped energy flux, energy dissipation, density of active reaction center per photosystem II (PSII) cross-section, the photosynthetic electron transport rate, the maximum photochemical efficiency of PSII photochemistry, and the rate of CO2 assimilation all decreased in COMT1-silenced plants compared with that of non-silenced plants particularly under heat stress. However, exogenous melatonin alleviated heat-induced photosynthetic inhibition in both genotypes, indicating that melatonin is essential for maintaining photosynthetic capacity under stressful conditions. These findings provide genetic evidence on the vital role of melatonin in photosynthesis and thus may have useful implication in horticultural crop management in the face of climate change. [ABSTRACT FROM AUTHOR]

Recent studies showed that HOXA1 can promote or suppress the transcription of target genes via binding to their promoter region, therefore regulating the development and progression of various cancers. However, the biological function of HOXA1 in bladder cancer (Bca) remains unknown. qRT-PCR and Western blot assay was performed to measure the mRNA protein level of HOXA1 in Bca cells. CCK-8 and cell colony formation assay were carried out to detect cell proliferation ability. Wound healing assay was applied to detect cell migration ability, while transwell assay was applied to detect cell invasion ability. Chromatin Immunoprecipitation (ChIP) and dual-luciferase reporter assay were used to investigate the molecular mechanisms underlying HOXA1. In this study, we discovered that HOXA1 mRNA and protein was dramatically increased in Bca tissues and cells compared to matched normal tissues and normal bladder epithelial cell. Enhanced HOXA1 expression was positively correlated with bigger tumor size and lymphatic metastasis, causing shorter overall survival to Bca patients. Knockdown of HOXA1 obviously impaired cell proliferation and metastasis ability. Further experiments proved that HOXA1 could strength the transcription of SMAD3 via binding to the promoter region of SMAD3. In conclusion, our study suggested that HOXA1 contributed to the growth and metastasis of Bca and it might serve as a tumor biomarker for Bca treatment and prognosis monitoring. [ABSTRACT FROM AUTHOR]

Abstract: The mitochondrial uncoupling protein genes improve plant stress tolerance by minimizing oxidative damage. However, the underlying mechanism of redox homeostasis and antioxidant signaling associated with reactive oxygen species (ROS) accumulation remained poorly understood. We introduced LeUCP gene into tomato line Ailsa Craig via Agrobacterium-mediated method. Transgenic lines were confirmed for integration into the tomato genome using PCR and Southern blot hybridization. One to three copies of the transgene were integrated into the tomato nuclear genome. Transcription of LeUCP in various transgenic lines was determined using real-time PCR. Transgenic tomato overexpressing LeUCP showed higher growth rate, chlorophyll content, maximum photochemical efficiency of PSII (Fv/Fm), photochemical quenching coefficient (qP) and electron transport rate (ETR), increased contents of AsA and proline, higher AsA/DHA ratio and GalLDH activity, reduced ROS accumulation, and enhanced heat stress tolerance compared with the control plants. The transgenic tomato plants also exhibited significant increases in tolerance against the necrotrophic fungus Botrytis cinerea. Taken together, our results suggest that LeUCP may play a pivotal role in controlling a broad range of abiotic and biotic stresses in plants by increasing redox level and antioxidant capacity, elevating electron transport rate, lowering H2O2 and lipid peroxidation accumulation. [Copyright &y& Elsevier]

Highlights: [•] AM fungi alleviated chilling stress-induced reduction of plant growth. [•] AMF induced higher secondary metabolites content and enzymatic activities. [•] Inoculation with AMF caused a reduction in H2O2 content under low temperature. [•] Secondary metabolites participate in AMF-mediated alleviation of chilling stress. [ABSTRACT FROM AUTHOR]

The effects of Cu contamination on RumexK-1 were studied using a pot trial. The results showed that the dry weight of leaves and roots did not change significantly under Cu stress when compared with CK (0 mg kg−1 Cu). Additionally, there was no difference in the amounts of chlorophylla, chlorophyllb, chlorophyll (a+b), and the chlorophylla/b ratio between the CK and Cu treatments. The Cu accumulated in leaves and roots, particularly in the roots, with more Cu accumulating in the plants at higher Cu concentrations in the soil. The proline and soluble protein contents in the leaves were more sensitive to Cu contamination than in the roots. Finally, Cu contamination significantly inhibited the acid phosphatase, alkaline phosphatase, and peroxidase activities in the leaves. These results indicate that RumexK-1 is a plant that can accumulate Cu, exhibits some different metabolic mechanisms under Cu stress, and may be suitable for the phytoremediation of Cu contaminated soils. [ABSTRACT FROM AUTHOR]

Phoxim, a broad-spectrum organophosphate pesticide, is widely used in agriculture to control insect pests in vegetable crops as well as in farm mammals. However, the indiscriminate use of phoxim has increased its release into the environment, leading to the contamination of plant-based foods such as vegetables. In this study, we investigated the effect of Trichoderma asperellum (TM, an opportunistic fungus) on phoxim residue in tomato roots and explored the mechanisms of phoxim metabolism through analysis of detoxification enzymes and gene expression. Degradation kinetics of phoxim showed that TM inoculation rapidly and significantly reduced phoxim residues in tomato roots. Phoxim concentrations at 5d, 10d and 15d post treatment were 75.12, 65.71 and 77.45% lower in TM + phoxim than only phoxim treatment, respectively. The TM inoculation significantly increased the glutathione (GSH) content, the activity of glutathione S -transferase (GST) and the transcript levels of GSH, GST1, GST2 and GST3 in phoxim-treated roots. In addition, the activity of peroxidase and polyphenol peroxidase involved in the xenobiotic conversion also increased in TM + phoxim treatment. The expression of detoxification genes, such as CYP724B2 , GR , ABC2 and GPX increased by 3.82, 3.08, 7.89 and 2.46 fold, respectively in TM + phoxim compared with only phoxim. Similarly, the content of ascorbate (AsA) and the ratio of AsA to dehydroascorbate increased by 45.16% and 57.34%, respectively in TM + phoxim-treated roots. Our results suggest that TM stimulates plant detoxification potential in all three phases (conversion, conjugation and sequestration) of xenobiotc metabolism, leading to a reduced phoxim residue in tomato roots. Image 1 • Trichoderma (TM) rapidly and significantly reduced phoxim residues in tomato roots. • Secondary metabolism-related enzymes activity was induced by TM. • TM inoculation enhanced glutathione content and GST activity. • TM upregulated the expression of detoxification genes (GSH1, GSTs, GR , ABC2, GPX). • TM promoted the phoxim metabolism by improving plant detoxification potential. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an emerging organic pollutant, widely distributed in environment. Plants can uptake and metabolize BPA, but BPA accumulation induces phytotoxicity. In this study, we administered dopamine, a kind of catecholamines with strong antioxidative potential, to unveil its role in cucumber tolerance to BPA stress. The results showed that exposure to BPA (20 mg L−1) for 21 days significantly reduced growth and biomass accumulation in cucumber seedlings as revealed by decreased lengths and dry weights of shoots and roots. While BPA exposure decreased the chlorophyll content, cell viability and root activity, it remarkably increased reactive oxygen species (ROS) accumulation, electrolyte leakage and malondialdehyde (MDA) content, suggesting that BPA induced oxidative stress in cucumber. However, exogenous dopamine application significantly improved the photosynthetic pigment content, root cell viability, growth and biomass accumulation, and decreased the ROS and MDA levels by increasing the activity of antioxidant enzymes under BPA stress. Further analysis revealed that dopamine application significantly increased the glutathione content and the transcripts and activity of glutathione S -transferase under co-administration of dopamine and BPA compared with only BPA treatment. Moreover, dopamine decreased the BPA content in both leaves and roots, suggesting that dopamine promoted BPA metabolism by enhancing the glutathione-dependent detoxification. Our results show that dopamine has a positive role against BPA phytotoxicity and it may reduce the risks-associated with the dietary intake of BPA through consumption of vegetables. Image 1 • Bisphenol A (BPA) causes phytotoxicity in cucumber by inducing oxidative stress. • Dopamine alleviates oxidative stress by improving antioxidant enzyme activity. • Dopamine enhances glutathione content and glutathione S -transferase activity. • Dopamine administration reduces BPA content in leaves and roots of cucumber. • Dopamine promotes metabolism of BPA and may improve food safety. [ABSTRACT FROM AUTHOR]

Abstract Potato cold-induced sweetening (CIS) is a major drawback restricting potato process industry. Starch degradation and sucrose decomposition are considered to be the key pathways in potato CIS. Our previous study showed that the RING finger gene SbRFP1 could slow down starch degradation and the accumulation of reducing sugars (RS) through inhibiting amylase and invertase activity in cold-stored tubers. However, the regulation mechanism of SbRFP1 is not clear. In this paper, we first proved that SbRFP1 could promote starch synthesis and modify the shape of starch granules. By further yeast two hybrid, GST-pull down and inhibition of enzyme activity assays, we confirmed that SbRFP1 could slow down the transformation of starch to RS in tubers mainly through the inhibition of β-amylase StBAM1 activity. SbRFP1 was also proved to possess E3 ubiquitin ligase activity by ubiquitination assay. Thus, SbRFP1 may regulate the accumulation of RS in cold-stored tubers by ubiquitination and degradation of StBAM1. Therefore, our study reveals the regulatory mechanism of SbRFP1 in the process of CIS and provides more powerful evidence for the effect of starch degradation on potato CIS. Highlights • SbRFP1 interact and inhibit the activity of StBAM1. • SbRFP1 possess E3 ubiquitin ligase activity. • SbRFP1 regulate the accumulation of RS in cold-stored tubers by ubiquitination and degradation of StBAM1. [ABSTRACT FROM AUTHOR]

Abstract: Chlorothalonil (CHT) and carbendazim (CAR) are two widely used fungicides in agriculture. Despite their agronomic importance in pest control, little is known about their detoxification in the plant. In this study, we investigated the effects of these fungicides on glutathione (GSH) content, GSH-dependent enzyme activities and gene expression in tomato leaves. Results showed that exposure to CHT resulted in increases in GSH content, activities of glutathione S-transferases (GSTs) and glutathione reductase (GR), as well as the transcriptional levels of glutathione S-transferase genes (GST1, GST2 and GST3), glutathione synthetase gene (GSH), glutathione reductase gene (GR) and glutathione peroxidase gene (GPX) in tomato leaves, but such increases were not observed in leaves exposed to CAR. In addition, GSTs, GR, peroxidase (POD) activities and most of GSH-dependent gene expression were induced by CHT in a concentration- and time-dependent manner. These results suggest that GSH-dependent pathway plays an important role in the CHT detoxification but not in the CAR detoxification in tomato leaves. [Copyright &y& Elsevier]

Highlights • COMT1 silencing reduces endogenous melatonin level in tomato leaves. • Melatonin deficiency aggravates high temperature-induced oxidative stress. • COMT1 silencing also impairs redox homeostasis under heat stress. • Exogenous melatonin increases endogenous melatonin in COMT1 -silenced plants. • Melatonin strengthens antioxidant defense and improves thermotolerance. Abstract Melatonin is a natural biostimulating molecule that occurs in a number of plant species. Despite a short history of phytomelatonin research, the critical roles of melatonin in plant stress responses have extensively been documented. However, the majority of such studies constitute 'pharmacological approach' and studies exploring the relevance of endogenous melatonin are scanty. As an attempt to unmask the role of endogenous melatonin in plant thermotolerance, we generated melatonin deficient tomato plants by silencing a gene, CAFFEIC ACID O-METHYLTRANSFERASE 1 (COMT1), involved in melatonin biosynthesis. We first examined the effect of exogenous melatonin and then performed a detailed analysis of the effect of melatonin deficiency on oxidative stress markers, enzymatic and non-enzymatic antioxidants, and redox homeostasis in tomato plants. The results showed that suppression of endogenous melatonin had an opposite effect of exogenous melatonin on tomato tolerance to high temperature stress. Endogenous melatonin deficiency aggravated high temperature-induced oxidative stress as evidenced by increased electrolyte leakage percentage, malondialdehyde concentration, and oxidized and insoluble protein accumulation in tomato leaves. These changes were accompanied with the significant reductions in the activity of ascorbate peroxidase and catalase, two key antioxidant enzymes that play prominent role in plant thermotolerance. Furthermore, silencing of COMT1 altered redox balance as reflected by the significantly decreased ratios of GSH:GSSG and AsA:DHA under high temperature stress. In contrast, exogenous melatonin augmented the endogenous melatonin level in COMT1 -silenced plants and alleviated the heat-induced oxidative stress. Our results suggest that an optimal endogenous melatonin level is critical, not only for its self-antioxidant capacity, but also for maintaining an efficient enzymatic antioxidant system and redox homeostasis under perturbed environmental conditions. [ABSTRACT FROM AUTHOR]

Anthocyanin is well-known plant colorant that accounts for the characteristic color of potato tubers and their excellent antioxidant properties. Anthocyanin synthesis involves several enzyme genes and transcription factors. In this paper, the expression of 10 enzyme genes and 11 transcription factors related to anthocyanin biosynthesis in 8 genotypes of colored potato tubers were examined. The results showed that chalcone synthase gene ( CHS ), flavanone 3-hydroxylase gene ( F3H ), dihydroflavonol 4-reductase gene ( DFR ), glutathione S-transferase gene ( GST ), flavonoid 3′,5′-hydroxylase gene ( F3′5′H ) and anthocyanidin synthase gene ( ANS ) play important roles in anthocyanin biosynthesis in colored potato tubers. Further analysis examining the expression correlation between transcription factors and enzyme genes indicated that 4 novel transcription factors, MYB11207 , MYB47415 , MYB79714 and bHLH31926 , may affect anthocyanin synthesis in tubers by regulating the expression of several enzyme genes, especially the MYB member MYB47415 . [ABSTRACT FROM AUTHOR]

[Display omitted] • Trichoderma (TM) significantly inhibited Botrytis (BC) growth in dual culture assay. • The control effect of TM on BC was up to 69.44% in greenhouse bioassay in tomato. • TM decreased H2O2 and MDA but improved the redox state under BC infection. • TM increased flavonoids, phenols and lignin contents and related gene expression. • TM improves photosynthesis, stomatal opening, RuBisCO activity and resistance to BC. Trichoderma harzianum (TM) is a soil-borne beneficial fungus that positively affects plant growth and defense. TM shows antagonism against multiple plant pathogens; however, the TM as a biocontrol agent against Botrytis cinerea (BC) and underlying mechanisms remain unclear. Herein we studied the effects of TM on BC by dual-culture assay and greenhouse bioassay in tomato plants. In vitro experiments showed that TM rapidly occupied most of the nutrient space and eventually covered BC on potato dextrose agar (PDA) medium. The TM inhibition rate against BC was 62.05% on the sixth day of culture. The inhibitory effect of TM spore suspension on gray mold inoculated with spore suspension and solid inoculants was 33.66% and 69.44%, respectively in tomato plants. Notably, TM decreased the leaf concentrations of BC-induced hydrogen peroxide and malondialdehyde but improved the redox state. TM inoculation caused biphasic peaks in the expression of secondary metabolism and defense-related genes and increased the concentrations of flavonoids, phenols and lignin in tomato leaves. Moreover, TM alleviated stomatal closure and enhanced the net photosynthesis rate and the activity of RuBisCO and FBPase compared with only BC inoculation. Our results suggest that TM spore suspension improves tomato resistance to gray mold disease by stimulating cellular redox, secondary metabolites and stomatal movement. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trichoderma strain TH effectively suppressed root-knot nematodes (RKNs) in tomato. • TH decreased the levels of H 2 O 2 , MDA and electrolyte leakage. • TH increased the concentrations of phenols, flavonoids, lignin, cellulose JA and SA. • TH upregulated the expression of PAL , C4H, 4CL, CAD , LPO, CCOMT , Tpx1 , and G6PDH. • TH increased the activity of β-1, 3-glucanase, chitinase, protease, and amylase. Trichoderma spp. can improve plant defense against diverse plant pathogens, including fungi, bacteria, viruses, and nematodes. Nonetheless, the underlying mechanisms of Trichoderma -induced enhanced resistance, particularly against plant-parasitic root-knot nematodes (RKNs), remain poorly understood. Here, we show that T. harzianum (TH) could effectively suppress RKN (Meloidogyne incognita) infestation with an RKN reduction percentage of 61.88% in tomato plants (Solanum lycopersicum L.). While RKN infections increased the levels of reactive oxygen species (ROS; H 2 O 2 and O 2 •‾) and lipid peroxidation in tomato roots, colonization with TH significantly reduced the levels of ROS, malondialdehyde, and electrolyte leakage, which was associated with increased accumulation of multiple secondary metabolites such as flavonoids, phenols, lignin, and cellulose on 75 days after inoculation with M. incognita. Consistent with the content of secondary metabolites, the activities of enzymes related to plant defense and the expression of associated genes (PAL , C4H, 4CL, CAD , LPO, CCOMT , Tpx1 , and G6PDH) significantly increased in TH + RKN-inoculated roots compared with that in only RKN-treated roots. Moreover, TH inoculation prior to RKN infestation significantly increased the activity of pathogenesis-related (PR) proteins such as β-1,3-glucanase, chitinase, protease, and amylase by 86.31%, 36.25%, 39.78%, and 17.06%, respectively, compared with the RKN-infested roots. Furthermore, TH significantly stimulated the levels of salicylic acid and jasmonic acid. These results indicate a positive role of TH in inducing resistance against the RKNs by promoting secondary metabolism and the activity and transcripts of defense-related enzymes in tomato roots. Our study unveiled critical mechanisms of Trichoderma -induced improved resistance to RKNs, which can be useful for developing sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

• Mycorrhiza for vegetable (VT) is the best AMF for watermelon among 8 consortiums. • 300 spores/plant caused the highest dry weight, photosynthetic rate, and dependence. • ABA, IAA and GA 3 concentrations were maximum with VT inoculation at 300 spore/plant. • VT reduced Rhizoctonia solani disease incidence with a 59.7% control effect. • VT alleviated R. solani –induced oxidative stress by improving antioxidant defense. The beneficial effects of arbuscular mycorrhizal fungi (AMF) vary depending on the species of fungi and host plants. In this study, we tested 8 mycorrhizal consortiums to explore the best AMF conformation for watermelon plants. The results showed that colonization with mycorrhiza for vegetable (VT) resulted in the highest biomass accumulation, photosynthetic rate, and dependence in watermelon seedlings. VT increased the photosynthetic rate and dry weight by 68.6% and 63.4%, respectively, compared with non-AMF plants. Dose trial on inoculum density for VT revealed that 300 spores per plant caused the highest dry weight, photosynthetic rate, and dependence. Notably, different inoculum density differentially affected endogenous hormone levels, whereas 300 spores/plant caused the highest accumulation of abscisic acid, indole acetic acid, and gibberellic acid. When VT-inoculated plants were infected with soil-borne fungal pathogen Rhizoctonia solani , they showed only 18.4% disease incidence with a 59.7% control effect compared with the 45.7% disease incidence in control plants without VT inoculation. R. solani decreased the photosynthetic rate, chlorophyll a , chlorophyll b , and carotenoid content by 38.8%, 20.5%, 63.4%, and 33.6%, respectively, while VT colonization significantly improved those indexes. Moreover, VT significantly reduced the relative electrolyte leakage, H 2 O 2 accumulation, and lipid peroxidation, and increased the root activity and antioxidant enzymes activities and their transcripts in roots, suggesting mitigation of oxidative stress caused by R. solani. Our results suggest that VT at optimal dose could enhance watermelon resistance to R. solani and thus can be considered as a biological control agent for R. solani management in cucurbits. [ABSTRACT FROM AUTHOR]

• Low-or high-Fe inhibited cucumber growth and induced chlorosis and oxidative stress • Melatonin alleviated oxidative stress and improved photosynthesis under iron stress • Melatonin promoted the activity and transcripts of antioxidant enzymes • Melatonin stimulated biosynthesis of secondary metabolites under iron stress • Melatonin altered Fe uptake and expression of FRO2 and IRT1 under iron stress Iron is an essential element for plants and animals; however, deficit or excess iron can result in stress on plants. In this study, we unveiled the mechanisms of shoot-based tolerance to iron toxicity by melatonin (N -acetyl-5-methoxytryptamine) in cucumber plants. Both low and high iron (Fe) supply in hydroponics decreased growth and biomass accumulation, induced chlorosis and oxidative stress, and reduced chlorophyll content, photosynthesis rate and transpiration rate in cucumber leaves. Notably, the negative effect of low-Fe was more profound than that of high-Fe treatment. However, exogenous melatonin application alleviated those inhibitions in growth, biochemical and physiological parameters, which entailed an elevation of endogenous melatonin content and a reduction of electrolyte leakage, reactive oxygen species accumulation and lipid peroxidation by improving the activity and transcripts of antioxidant enzymes and secondary metabolism-related enzymes, and concentrations of phenols and flavonoids under low and high iron conditions after melatonin treatment. Analysis of iron content in leaves and roots revealed that melatonin significantly increased the iron content under low-Fe conditions, but it decreased the same under high-Fe conditions. Moreover, melatonin increased the transcript levels of FRO2 and IRT1 under low-Fe, but it decreased those transcripts under high-Fe, suggesting that melatonin plays a dual role in iron uptake under low and high iron conditions. This study expands the stress ameliorative role of melatonin in plants and may have potential implications in agronomic management of crops in low and high iron prone soils. [ABSTRACT FROM AUTHOR]