Drought is a major abiotic stress that threatens agricultural output worldwide. Though plants respond to drought stress by increasing antioxidant potential, such increases are often insufficient to mitigate drought damage. Melatonin (N-acetyl-5-methoxytryptamine) is a potent natural antioxidant that alleviates drought stress; however, its effects on chili under drought remain largely unknown. The current study examined the effects of exogenous melatonin on chili pepper under varying drought conditions (70

Soil pollutants, both organic and inorganic, pose a significant threat to agricultural productivity and food safety. Arbuscular mycorrhizal fungi (AMF), a group of widespread soil fungi, can enhance plant tolerance to soil pollutants. This review aims to consolidate current knowledge on soil pollution and the mechanisms by which AMF enhance plant tolerance to various soil pollutants, including heavy metals and organic pollutants, thereby contributing to soil health and ecosystem resilience. Soil pollutants damage soil's physical, chemical, and biological properties, leading to reduced soil fertility and lower crop yields. AMF form symbiotic relationships with most terrestrial plants, facilitating the uptake of water and nutrients, particularly phosphorus, nitrogen, and sulfur. This mutualistic exchange of resources is crucial for ecosystem services. The symbiosis also strengthens plant resilience to soil pollutants. The enhancement of plant stress tolerance can be attributed to both the direct effects of AMF on pollutants and the indirect impact of AMF symbiosis on plant nutrient uptake and physiological regulation. The latter leads to increased detoxification of pollutants through chelating compounds such as phytochelatins, metallothioneins, and glutathione. This review provides an overview of soil pollutants, including their types, sources, and impacts. The review also explores the physiological and molecular mechanisms of AMF-induced alleviation of phytotoxicity and AMF-assisted remediation of soil pollutants. This synthesis of information provides a comprehensive understanding of the multifaceted roles of AMF in promoting plant and soil health and offers promising prospects for agricultural production, bioremediation, and ecological restoration in polluted soils.

The dynamic interaction between plants and their root-associated microbiota represents a sophisticated and profound biological communication that regulates plant development and the formation of adaptation to the surrounding environment. These interactions function as critical regulators of multiple physiological processes, finally influencing soil fertility and agricultural productivity. Plants have evolved epigenetic networks that regulate beneficial plant-microbe interactions through regulating immune responses, gene regulation, and metabolite production to enhance stress tolerance and soil adaptation. These regulations collectively govern microbial colonization patterns while establishing reciprocal feedback loops through root exudate-microbe interactions. This review systematically updates contemporary advances in understanding how epigenetic modifications shape rhizosphere microbiome composition and function, and discusses their potential applications in enhancing the yield and quality of horticultural crops, as well as in mitigating continuous cropping obstacles.

Brassinosteroids (BRs) are steroidal phytohormones that play crucial roles in plant growth and resilience. The stability of BRASSINAZOLE RESISTANT 1 (BZR1), the central transcription factor of BR signaling, is controlled by the GSK3-like kinase BRASSINOSTEROID INSENSITIVE 2 (BIN2)-dependent phosphorylation. However, the regulators mediating BZR1 degradation remain elusive. Here, we identify a BZR1-interacting WD40-repeat protein (BIW) that facilitates ubiquitination and degradation of BZR1 in tomato (Solanum lycopersicum). Mutations in BIW lead to growth phenotypes similar to those of plants with elevated BR signaling, accompanied by enhanced chilling tolerance, whereas overexpressing BIW results in the opposite phenotypes and reduced chilling tolerance. Furthermore, phosphorylation of BIW at Ser144 by BIN2 is essential for its stability and activity. Our findings demonstrate that BIW is an integral component of BR signaling and represents a potential target for genetic modification aimed at improving resilience and productivity.

Root-associated beneficial microbes can enhance plant resistance at the systemic level without triggering constitutive defense activation, yet how such durable and low-cost immune states are established remains poorly understood. Plant-Trichoderma spp. mutualism represents a well-characterized model of beneficial plant-microbe interactions in which induced resistance is maintained despite the absence of sustained transcriptional defense outputs. Accumulating evidence implicates small RNAs, including microRNAs (miRNAs), small interfering RNAs (siRNAs), and long non-coding RNAs (lncRNAs), as central regulators of immune priming during Trichoderma-plant interactions. Such RNA-mediated processes shape defense responsiveness, hormonal sensitivity, and chromatin-associated regulation. In parallel, epigenetic modifications have been linked to the persistence and reversibility of primed immune states. However, these regulatory layers are often examined separately, limiting mechanistic understanding of how immune states are both stabilized and flexibly reprogrammed. In this conceptual review, we synthesize recent advances to examine Trichoderma-induced systemic immunity through an integrated RNA-epigenetic perspective. By viewing RNA-mediated regulation and epigenetic modification as components of a functional continuum, we illustrate how immune priorities defined by small RNAs can be consolidated into chromatin states that preserve inducibility without imposing constitutive costs. This framework provides a coherent explanation for how Trichoderma-induced immunity is organized across molecular layers in plants.

Tomato leaf mold, caused by Cladosporium fulvum, is a destructive foliar disease in protected cultivation. Biological control using Trichoderma and plant defense elicitors such as melatonin offers a sustainable alternative to chemical fungicides. However, the synergistic effect of combining Trichoderma with melatonin and the role of endogenous melatonin in Trichoderma-induced resistance to tomato leaf mold remain unclear. In this study, we screened ten Trichoderma strains and identified T. asperellum T141 strain as the most effective antagonist against C. fulvum in dual culture assays. Moreover, exogenous melatonin (100 μmol/L) resulted in the lowest disease index and significantly reduced malondialdehyde content. The combined application of T. asperellum and melatonin prior to pathogen inoculation reduced the disease index by 77.57% and promoted plant growth compared with pathogen-only controls. The combination also decreased H2O2 and O2·-, elevated antioxidant enzyme (SOD, POD, CAT, and APX) activities, and restored photosynthetic parameters, pigment contents, Rubisco activity, FBPase activity, and expression of photosynthesis-related genes (FBPase, SBPase, FBPA, and TPI). Virus-induced gene silencing of the COMT1 gene, a key melatonin biosynthesis gene, drastically reduced endogenous melatonin, and largely compromised T. asperellum-induced resistance, along with attenuated antioxidant defense and photosynthetic recovery. Collectively, our results demonstrate that T. asperellum and melatonin synergistically protect tomato against C. fulvum by mitigating oxidative stress and preserving photosynthetic function, and that COMT1-dependent endogenous melatonin synthesis is essential for T. asperellum-induced resistance. This study provides a theoretical basis for developing Trichoderma-melatonin biopreparations as an eco-friendly strategy for the management of tomato leaf mold.

Theanine, a tea-enriched nonprotein amino acid, plays key roles in plant metabolism and stress adaptation. To test whether theanine biosynthesis can be reconstructed in a nontea crop and whether this metabolic network contributes to stress tolerance, we heterologously expressed the tea alanine decarboxylase gene CsAlaDC in tomato (Solanum lycopersicum cv. Micro-Tom). The resulting OE-CsAlaDC lines accumulated ethylamine and synthesized theanine without introducing a tea theanine synthase gene, demonstrating that endogenous tomato glutamine synthetase supports theanine formation. Transgenic plants exhibited distinct morphological changes, including dwarfism and dark-green leaves, while their fruits showed accelerated development, elevated levels of theanine and GABA, and improved quality-related traits such as enhanced lycopene accumulation. Under heat stress, OE-CsAlaDC plants maintained higher PSII efficiency, reduced membrane damage and reactive oxygen species accumulation, and stronger antioxidant enzyme activities than wild-type plants. Exogenous theanine further enhanced thermotolerance, promoted SlGAD1/2 expression, and increased GABA accumulation, whereas silencing SlGAD1 and SlGAD2 markedly diminished the protective effect of theanine. Exogenous ethylamine also conferred partial heat protection, but theanine showed a stronger association with GAD-dependent GABA biosynthesis. Collectively, these findings demonstrate that heterologous expression of CsAlaDC establishes a functional ethylamine-theanine metabolic branch in tomato and enhances thermotolerance through coordination with the GABA metabolic network, offering a promising strategy to improve both stress resilience and nutritional quality in crops.

Trichoderma is a widely studied fungal genus recognized for its ability to promote plant growth, enhance stress tolerance, and provide biological control. Biocontrol by Trichoderma involves multiple mechanisms, including resource competition, mycoparasitism, secretion of cell wall‑degrading enzymes, production of volatile organic compounds, and the release of antimicrobial metabolites. During root colonization, fungal elicitors, effector‑like proteins, and metabolite‑derived signals are perceived by plant cells and activate host immune responses. Molecules such as Sm1/Epl1, LysM effectors, gliotoxin, and VOC/Nox-associated signals examplify how root-associated Trichoderma strains modulate local and systemic defense responses. However, Trichoderma-induced immunity does not conform neatly to classical systemic acquired resistance or induced systemic resistance frameworks, owing to its non‑canonical and context‑dependent signaling features. Although salicylic acid-, jasmonic acid-, and ethylene-related pathways are central, they interact extensively with reactive oxygen species signaling, MAPK cascades, phenylpropanoid metabolism, oxylipin pathways, and RNA-mediated and epigenetic regulation. Consequently, defense outcomes vary widely depending on fungal strain, host genotype, pathogen lifestyle, and environmental conditions. This review synthesizes recent mechanistic and translational advances in Trichoderma-plant interactions and evaluates formulation strategies, delivery methods, field performance, biosafety considerations, and commercialization challenges. Strengthening the links between molecular understanding, strain screening, product development, and field validation will be essential for improving the reliability of Trichoderma-based biocontrol in sustainable agriculture.

Low temperatures pose a significant threat to agricultural production, particularly during early spring, late autumn, and winter in northern China, adversely affecting the yield and quality of cold-sensitive crops, such as tomato (Solanum lycopersicum L.). Nano-silicon (SiNPs) represent a prominent application of nanotechnology in agriculture, owing to their unique structure and physicochemical properties, which have demonstrated remarkable efficacy in enhancing plant stress resistance. In this study, we utilized 'Zhongza 9 ' tomato cultivar as the test material to investigate the effects of SiNPs, applied through foliar spraying at a concentration of 100 mg & sdot;L- 1, on nutrient uptake and the microbiome of tomato roots under low-temperature stress. The experiments were conducted using substrate culture at room temperature (25/16 degrees C) and low temperature (15/6 degrees C). The results indicated that the application of SiNPs could enhance the cold tolerance of tomato plants by improving root configuration, photosynthetic capacity, antioxidant capacity, carbon and nitrogen metabolism, as well as nutrient absorption and utilization. Furthermore, SiNPs were found to influence the structure of the rhizosphere microbial community, thereby promoting soil nutrient release. This study elucidates the intricate dynamics between roots, soil, and microbes in mitigating low-temperature stress in plants. Moreover, it provides a crucial theoretical framework for advancing the utilization of SiNPs in agricultural contexts, offering valuable insights for enhancing agricultural productivity in challenging environmental conditions.

Toxic heavy metal chromium (Cr) poses significant risks to crop yields and human health through contamination of the food chain. Dopamine, a naturally occurring bioactive amine, can enhance plant tolerance to various abiotic stresses; however, its specific role in Cr stress tolerance and the associated molecular mechanisms remain largely unexplored. In this study, we demonstrate that root application of dopamine effectively mitigates Cr stress in tomato plants. Cr stress was found to decrease chlorophyll content, maximum photochemical efficiency, shoot growth, and biomass accumulation, while simultaneously increasing reactive oxygen species (ROS) accumulation, lipid peroxidation, and electrolyte leakage. Exogenous dopamine application significantly reduced excessive ROS accumulation and malondialdehyde levels, thereby alleviating oxidative stress. This was achieved through the enhancement of antioxidant enzyme activity, increased glutathione and phytochelatin contents, and the upregulation of the expression of respective encoding genes, including Cu-Zn SOD, POD, CAT1, APX, GR1, GSH2, and PCS. Additionally, dopamine treatment induced the expression of RBOH1 and reduced Cr content. Notably, exogenous H2O2 application also improved Cr tolerance, but the application of diphenyleneiodonium, an NADPH oxidase inhibitor, exacerbated Cr phytotoxicity and diminished the beneficial effects of dopamine on plant tolerance to Cr stress. These findings suggest that dopamine-induced H2O2 signaling plays a crucial role in enhancing Cr tolerance. This study elucidates a fundamental mechanism underlying dopamine-mediated Cr tolerance and expands our understanding of the stress resistance properties of dopamine in plants.

Root-knot nematode (RKN) infestation is a major threat to global agriculture, causing substantial damage to economically important crops such as tomatoes. Trichoderma species are promising biocontrol agents that can enhance plant growth, improve nutrient uptake, and induce systemic resistance against various pathogens, including RKNs. The R2R3-MYB transcription factor family plays a key role in plant secondary metabolism and defense mechanisms against biotic stressors. However, the specific role of tomato MYB108 in mediating resistance against RKNs remains underexplored. In this study, we found that RKN infestation decreases MYB108 expression, whereas Trichoderma harzianum inoculation significantly enhances MYB108 expression. Silencing MYB108 expression in tomato plants using the virus-induced gene silencing (VIGS) technique enhances susceptibility to RKNs as evidenced by a marked increase in gall number and root galling index (increased by 16.53 % and 16.10 %, respectively), alongside a reduction in the biocontrol efficacy of Trichoderma (decreased by 29 %). Furthermore, MYB108 silencing exacerbates RKN-induced oxidative stress, as evinced by elevated levels of hydrogen peroxide, superoxide anion, malondialdehyde, and electrolyte leakage. MYB108 silencing also attenuates the accumulation of key secondary metabolites such as flavonoids, phenols, and lignins, and reduces the activities of enzymes and the expression of genes associated with secondary metabolite synthesis. Although Trichoderma inoculation mitigates RKN-induced oxidative stress and enhances secondary metabolite synthesis, the silencing of MYB108 refutes the beneficial effects of Trichoderma on both secondary metabolite production and antioxidant capacity. Analysis of the transcriptional start site located 2000 base pairs upstream of the promoter regions of PAL, C4H, 4CL, and DFR reveals multiple MYB binding sites, indicating that MYB108 potentially plays a significant role in the transcriptional regulation of secondary metabolism. En masse, these findings highlight the critical role of MYB108 in mediating Trichoderma-induced resistance to RKNs and emphasize its potential as a target for enhancing plant resilience to RKNs.

Silicon-nanomaterials (Si-NMs) have emerged as a revolutionary tool in modern agriculture; however, the collaborative role of Si-NMs in onion crop productivity and expansion in acidic soils remains elusive. We conducted a series of sequential experiments, from seed germination to field trials, over two consecutive cultivation years. Intriguingly, the results revealed that among the differential doses, 1.0 mM L−1 of Si-NMs significantly ameliorated the acid-stress-induced suppression of onion seed germination and seedling growth. Additionally, a selected dose of Si-NMs reduces seedling mortality and improves plant establishment rate with increased photosynthetic performance, bulb properties, and nutritional quality. These stimulatory effects of Si-NMs on onion crop adaptation to acidic soil were associated with reduced ROS accumulation driven by enhanced antioxidant potential, which further increased upon dolomite supplementation. Furthermore, exogenous Si-NMs spray accelerated the early stages of harvestable onion size, accompanied by increased synthesis of IAA and GA3 hormones, suggesting the potential of Si-NMs to enhance farm resilience in acidic soils.

The genus Trichoderma comprises a group of fungi known for their beneficial effects on plant growth and stress tolerance. Light is a key environmental factor affecting many plant physiological processes. However, a significant research gap remains regarding the interaction between light quality and Trichoderma harzianum inoculation, particularly their combined effects on tomato plant growth and photosynthetic efficiency. Here, we showed that T. harzianum inoculation effectively alleviated the growth inhibition caused by monochromatic red light or blue light in tomato plants. Combined red and blue light treatment with T. harzianum inoculation (RBT) promoted root development by regulating the rational distribution of carbon assimilation products. Specifically, the RBT treatment upregulated the expression of photosynthesis-related genes, including key Calvin cycle enzyme genes such as FBPase, FBPA, TPI, and SBPase, as well as the light signal transduction factor HY5. In addition, T. harzianum inoculation increased the maximal photochemical efficiency of PSII (Fv/Fm), and the net photosynthetic rate (Pn). The activity of sucrose synthetase (SS) and sucrose phosphate synthetase (SPS) was also enhanced, promoting photosynthetic product accumulation in leaves and roots. Among all treatment groups, RBT performed the best in the above indexes.

The water-saving and fertilizer-reduction strategies is important for sustainable agricultural development. However existing kiwifruit water-saving and fertilizer-reduction studies showed significant contradictions in the results of water and fertilizer management. Studies have reported conflicting findings on irrigation: some suggest over-irrigation increases yield and WUE, while others advocate low-volume irrigation. Consequently, this study offers a comprehensive meta-analysis encompassing 1038 observations, with the objective of evaluating the influence of water management and optimized fertilization on the yield, water use efficiency (WUE), and quality of kiwifruit. The results showed that the response of kiwifruit to water management was particularly significant in areas with annual average rainfall > 800 mm and field water holding capacity > 28%, and excessive irrigation had a greater negative impact on yield and WUE. With the increase of tree age, the yield-increasing effect of kiwifruit on water and fertilizer optimization gradually weakened. In terms of irrigation methods, drip irrigation has more advantages than traditional irrigation methods. Reducing super-optimal input (SOI) water input can increase kiwifruit yield by 16.24% and WUE by 20.06%. In terms of fertilization management, reducing the input of SOI nitrogen fertilizer can significantly increase the yield of kiwifruit by 32.76%, while reducing the input of SOI nitrogen, phosphorus and potassium can increase the yield by 3.45%. The contents of soluble sugar and vitamin C increased by 6.35% and 18.37%, respectively, but the contents of titratable acid and soluble solids decreased by 4.35% and 6.18%, respectively. In addition, the optimal nitrogen fertilizer level for kiwifruit varies from region to region, and it is generally recommended to be between 100 – 105 kg/ha per hectare. In summary, scientific and reasonable water and fertilizer management can significantly improve the yield and quality of kiwifruit, optimize WUE, and reduce water and fertilizer waste, providing theoretical basis and practical guidance for sustainable agricultural development.

As one of the grave environmental hazards, soil salinization seriously limits crop productivity, growth, and development. When plants are exposed to salt stress, they suffer a sequence of damage mainly caused by osmotic stress, ion toxicity, and subsequently oxidative stress. As sessile organisms, plants have developed many physiological and biochemical strategies to mitigate the impact of salt stress. These strategies include altering root development direction, shortening the life cycle, accelerating dormancy, closing stomata to reduce transpiration, and decreasing biomass. Apart from being a prime energy source, light is an environmental signal that profoundly influences plant growth and development and also participates in plants' response to salt stress. This review summarizes the regulatory network of salt tolerance by light signals in plants, which is vital to further understanding plants' adaptation to high salinity. In addition, the review highlights potential future uses of genetic engineering and light supplement technology by light-emitting diode (LED) to improve crop growth in saline-alkali environments in order to make full use of the vast saline land.

Tomato is an important economic crop all over the world. Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality. However, the regulatory mechanism controlling the volatile flavors of tomatoes is still not clear. Here, we integrated the metabolome and transcriptome of the volatile flavors in tomato fruit to explore the regulatory mechanism of volatile flavor formation, using wild and cultivated tomatoes with significant differences in flavors. A total of 35 volatile flavor compounds were identified, based on the solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The content of the volatiles, affecting fruit flavor, significantly increased in the transition from breaker to red ripe fruit stage. Moreover, the total content of the volatiles in wild tomatoes was much higher than that in the cultivated tomatoes. The content variations of all volatile flavors were clustered into 10 groups by hierarchical cluster and Pearson coefficient correlation (PCC) analysis. The fruit transcriptome was also patterned into 10 groups, with significant variations both from the mature green to breaker fruit stage and from the breaker to red ripe fruit stage. Combining the metabolome and the transcriptome of the same developmental stage of fruits by co-expression analysis, we found that the expression level of 1 182 genes was highly correlated with the content of volatile flavor compounds, thereby constructing two regulatory pathways of important volatile flavors. One pathway is tetrahydrothiazolidine N-hydroxylase (SlTNH1)-dependent, which is regulated by two transcription factors (TFs) from the bHLH and AP2/ERF families, controlling the synthesis of 2-isobutylthiazole in amino acid metabolism. The other is lipoxygenase (SlLOX)-dependent, which is regulated by one TF from the HD-Zip family, controlling the synthesis of hexanal and (Z)-2-heptenal in fatty acid metabolism. Dual-luciferase assay confirmed the binding of bHLH and AP2/ERF to their structural genes. The findings of this study provide new insights into volatile flavor formation in tomato fruit, which can be useful for tomato flavor improvement.

Tea anthracnose is a major disease of tea plant (Camellia sinensis) in all tea-growing regions in China, with the southern tea region being particularly susceptible. Over the past decade, more than 20 species belonging to Colletotrichum have been identified as causal agents of tea anthracnose besides its actual pathogen Discula theae-sinensis. Although researchers have increasingly regarded Colletotrichum spp. as the primary pathogens of tea anthracnose, there is still controversy over whether they cause tea anthracnose. By employing spore isolation methods, here we identified a fungal strain causing typical tea anthracnose disease but not belonging to the genus Colletotrichum. Upon spore isolation of tea anthracnose pathogens, various methods were employed to determine the pathogenicity of the isolate cultures. Eventually, a single isolate was obtained through the spore isolation method, which was subsequently identified as Sinodiscula theae-sinensis (Discula theae-sinensis) based on its morphological and molecular characteristics. The pathogenicity assay revealed that with either wound or non-wound inoculation the isolate exhibited typical lesions that were identical to those observed on the original diseased leaves. Furthermore, all the re-isolation strains obtained from the inoculated leaves was identical to the original strain. The pathogen of tea anthracnose was further confirmed as S. theae-sinensis by Koch's validation. Additionally, the symptomatic manifestations of the inoculation by S. theae-sinensis and Colletotrichum camelliae were also compared. The symptoms induced by C. camelliae are distinct from those observed in anthracnose. This study clarified the causal pathogen of tea anthracnose, thus a crucial foundation for the identification, prevention, and control of tea anthracnose.

L-theanine, a unique non-protein amino acid predominantly found in tea plants (Camellia sinensis), plays a pivotal role in plant responses to abiotic stress and significantly influences tea quality. In this review, the metabolism and transport mechanisms of L-theanine are comprehensively discussed, highlighting its spatial distribution in tea plants, where it is most abundant in young leaves and less so in roots, stems, and older leaves. The biosynthesis of L-theanine occurs through the enzymatic conversion of glutamate and ethylamine, catalyzed by theanine synthase, primarily in the roots, from where it is transported to aerial parts of the plant for further catabolism. Environmental factors such as temperature, light, drought, elevated CO2, nutrient unavailability, and heavy metals significantly affect theanine biosynthesis and hydrolysis, with plant hormones and transcription factors playing crucial regulatory roles. Furthermore, it has been demonstrated that applying L-theanine exogenously improves other crops’ resistance to a range of abiotic stresses, suggesting its potential utility in improving crop resilience amid climate change. This review aims to elucidate the physiological mechanisms and biological functions of L-theanine metabolism under stress conditions, providing a theoretical foundation for enhancing tea quality and stress resistance in tea cultivation.

Climate change has profound impacts on plant growth, productivity, and immunity. Photosynthesis, a key biological process that sequesters atmospheric CO2, plays a crucial role in mitigating the effects of climate change. However, photorespiration, a process that consumes O2 instead of CO2 and is metabolically linked with photosynthesis, is often viewed as a wasteful process that reduces photosynthetic efficiency by nearly 48 % in C3 plants. This reduction has a significant impact on crop yield, given the direct contribution of photosynthesis to biomass accumulation. Over the years, numerous efforts have been made to rectify this perceived metabolic flaw to enhance photosynthetic efficiency. Interestingly, recent studies have unveiled a role for photorespiration in plant immunity, which can vary from positive to negative depending on the plant-pathosystem. A key challenge lies in enhancing photosynthetic efficiency by modulating photorespiration without compromising plant immunity. This review discusses the role of photorespiration in plant immunity under current and future climatic conditions. We explore how photorespiration and photorespiratory pathways influence plant defense, how alterations in photorespiration affect hormonal pathways and subsequently plant immunity, and how manipulations of photorespiration may impact plant growth and defense under elevated CO2 conditions. We highlight the roles of plant hormones such as salicylates and jasmonates as well as reactive oxygen species, in photorespiration-related plant immunity. We conclude that unraveling the underlying mechanisms of photorespiration-involved plant responses to various pathogens provides comprehensive insights for the management, breeding, and genetic improvement of crops, thereby enhancing their resilience to future climate change.