Search Results (1,183)

Maize (Zea mays L.) is a major economic crop highly susceptible to Colletotrichum graminicola, the causal agent of anthracnose leaf blight, which causes substantial annual yield losses. This fungal pathogen employs numerous effectors to manipulate plant immunity, yet the functions of many secreted proteins during biphasic infection remain poorly characterized. In this study, we identified CgMas2, a candidate secreted protein in C. graminicola and a homolog of Magnaporthe oryzae MoMas2. Deletion of CgMAS2 in the wild-type strain CgM2 did not affect fungal vegetative growth or conidial morphology but significantly impaired virulence on maize leaves. Leaf sheath infection assays revealed that CgMas2 is required for biotrophic invasive hyphal growth, as the mutant showed defective spreading of invasive hyphae to adjacent cells. Subcellular localization analysis indicated that CgMas2 localizes to the cytoplasm of conidia and to the primary infection hyphae. Furthermore, DAB staining demonstrated that disrupt of CgMAS2 leads to host reactive oxygen species (ROS) accumulation. Comparative transcriptome analysis of maize infected with ΔCgmas2 versus CgM2 revealed enrichment of GO terms related to peroxisome and defense response, along with up-regulation of benzoxazinoid biosynthesis genes (benzoxazinone biosynthesis 3, 4 and 5) at 60 h post-inoculation (hpi). Conversely, six ethylene-responsive transcription factors (ERF2, ERF3, ERF56, ERF112, ERF115 and ERF118) involved in ethylene signaling pathways were down-regulated at 96 hpi. These expression patterns were validated by RT-qPCR. Collectively, our results demonstrate that CgMas2 not only promotes invasive hyphal growth during the biotrophic stage but may also modulate phytohormone signaling and defense compound biosynthesis during the necrotrophic phase of infection. Full article

The pepper Bs2 resistance gene confers resistance to susceptible Solanaceae plants against pathogenic strains of Xanthomonas campestris pv. vesicatoria carrying the avrBs2 avirulence gene. Previously, we generated Bs2-transgenic Citrus sinensis plants that exhibited enhanced resistance to citrus canker caused by Xanthomonas citri subsp. citri (Xcc), although the underlying mechanisms remained unknown. To elucidate the molecular basis of the early defense response, we performed a comparative transcriptomic analysis of Bs2-expressing and non-transgenic plants 48 h after Xcc inoculation. A total of 2022 differentially expressed genes (DEGs) were identified, including 1356 up-regulated and 666 down-regulated genes. In Bs2-plants, 36.8% of the up-regulated DEGs were associated with defense responses and biotic stress. Functional annotation revealed major changes in genes encoding receptor-like kinases, transcription factors, hormone biosynthesis enzymes, pathogenesis-related proteins, secondary metabolism, and cell wall modification. Among hormone-related pathways, genes linked to ethylene biosynthesis and signaling were the most strongly regulated. Consistently, endogenous ethylene levels increased in Bs2-plants following Xcc infection, and treatment with an ethylene-releasing compound enhanced resistance in non-transgenic plants. Overall, our results indicate the Bs2 expression activates a complex defense network in citrus and may represent a valuable strategy for controlling canker and other Xanthomonas-induced diseases. Full article

Microplastics (MPs) and nanoplastics (NPs) have emerged as pervasive pollutants across different aquatic systems on a global basis, yet integrated assessments linking wastewater, riverine, and marine environments remain scarce. The present study provides the first comprehensive evaluation of MPs in three interconnected aquatic matrices of Northern Greece, namely surface seawater from the Thermaic Gulf, surface freshwater from the Axios River, and influent and effluent wastewaters from the Thessaloniki WWTP (Sindos). During two sampling periods spanning late 2023 and spring 2024, suspected MPs were isolated, morphologically classified by stereomicroscopy, and chemically characterized through pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). MPs were ubiquitously detected in all substrates, exhibiting distinct spatial and compositional patterns. Seawater samples displayed moderate concentrations (1.5–4.8 items m⁻³) dominated by fibers and fragments, while riverine samples contained slightly higher levels (0.5–2.5 items m⁻³), enriched in fibrous forms and polyolefins (PE, PP). Wastewater influents showed the highest MP abundance (78–200 items L⁻¹; 155.6–392.3 µg L⁻¹), decreasing significantly in effluents (11–44 items L⁻¹; 27.8–74.3 µg L⁻¹), corresponding to a removal efficiency of 81–87.5%, being the first indicative removal efficiencies in a Greek WWTP. Among the different polymers detected, polyethylene, polypropylene, and poly(ethylene terephthalate) were identified as the most prevalent polymers across all matrices. Interestingly, a shift toward smaller size classes (125–500 µm) in effluents indicated in-plant fragmentation processes, while increased concentrations during December coincided with increased rainfall, highlighting the influence of hydrological conditions on MP fluxes. The combined morphological and polymer-specific approach provides a holistic zunderstanding of MP transport from inland to marine systems, establishing essential baseline data for Mediterranean environments and reinforcing the need for integrated monitoring and mitigation strategies. Full article

Ethylene is a multifunctional phytohormone that regulates plant growth, development, and responses to abiotic/biotic stresses. RTE1 (Reversion-To-Ethylene Sensitivity1) acts as a negative regulator of the ethylene responses in Arabidopsis by positively regulating ethylene receptor ETR1. However, the role of RTE genes in sweet potato (Ipomoea batatas), an import food crop worldwide, remains largely unknown, particularly their involvement in abiotic stress adaptation. In this study, we identified 23 RTE genes in sweet potato, distributed across 21 chromosomes and one scaffold BrgTig00017944. The phylogenetic analysis divided them into two groups, the RTE1 group and RTH (RTE1-Homolog) group. Synteny analysis revealed that whole genome duplication (WGD) was the major force of expansion of the IbRTE gene family. Multiple cis-acting elements responsive to hormones and stress were found in the promoter region of IbRTE genes. The transcriptome expression profiling showed that the majority of IbRTEs have tissue-specific and differential expression under drought and salt stresses. Meanwhile, the qRT–PCR results showed that the 14 representatives IbRTEs have differential expression profilings under salt (NaCl) and drought (PEG) treatments. These findings suggest that the IbRTE genes may be involved in sweet potato’s adaptive responses to salt and drought, providing a valuable foundation for further functional studies. Full article

Grafting is a pivotal horticultural technique for enhancing vegetable crop productivity; however, the specific molecular mechanisms governing rootstock-induced vigor remain insufficiently elucidated. This study deciphers how bottle gourd rootstock augments growth in melon scions through an integrated approach combining physiology, transcriptomics, phytohormone profiling, and functional genetics. Phenotypic analysis confirmed a significant increase in plant height, fresh weight, and stem diameter in heterografted scions compared to controls. Transcriptome sequencing of scion apices identified 663 core differentially expressed genes (DEGs) specifically modulated by the bottle gourd rootstock. These DEGs were prominently enriched in carbohydrate metabolism and plant hormone signal transduction pathways. Consistent with this, hormonal assays revealed a specific elevation in cytokinin and ethylene levels in the scion, accompanied by the upregulation of key pathway genes, including MELO3C016881 (LOG) and MELO3C007769 (ERF060). Crucially, virus-induced gene silencing of either gene completely abolished the rootstock-conferred growth advantage. Our findings preliminarily unveil the secret behind scion vigor, providing a foundational mechanistic framework for how rootstocks reprogram scion development. The identified genes, MELO3C016881 and MELO3C007769, offer direct molecular targets for the precision breeding of superior scions in melon. Full article

Antimicrobial resistance (AMR) is one of the major health threats of the 21st century and demands innovative sources of bioactive compounds. In 2019, infections caused by resistant bacteria directly accounted for 1.27 million deaths and contributed to an additional 4.95 million associated deaths, underscoring the urgency of exploring new strategies. Among emerging alternatives, specialized plant metabolites stand out, as their biosynthesis is enhanced under biotic or abiotic stress. These stimuli increase reactive oxygen species (ROS), activate cascades regulated by mitogen-activated protein kinases (MAPKs), and trigger defense-related hormonal pathways involving salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and abscisic acid (ABA), which in turn regulate transcription factors and biosynthetic modules, promoting the accumulation of compounds with antimicrobial activity. In this review, we synthesize recent literature (2020–2025) with emphasis on studies that report quantitative activity metrics. We integrate evidence linking stress physiology and metabolite production, summarize mechanisms of action, and propose a conceptual multi-omics pipeline, synthesized from current best practices, that combines RNA sequencing and LC/GC-MS-based metabolomics with bioinformatic tools to prioritize candidates with antimicrobial potential. We discuss elicitation strategies and green extraction, highlight bryophytes (e.g., Pseudocrossidium replicatum) as a differentiated chemical source, and explore citrus Huanglongbing (HLB) as a translational case study. We conclude that integrating stress physiology, multi-omics, and functional validation can accelerate the transition of stress-induced metabolites toward more sustainable and scalable medical and agricultural applications. Full article

Flavonols are an important secondary metabolite in grape, which play a crucial role in plant growth and development, human health, and wine making. Ethylene and its inhibitor 1-Methylcyclopropene (1-MCP) are widely used in grape berry production. However, the regulation mechanism of flavonol biosynthesis by ethylene and 1-MCP remains elusive in yellow-green grape varieties. Here, the content of flavonols in ‘Chardonnay’ grape berry skin after ethylene treatment was significantly higher than the control, while 1-MCP treatment was lower than the control. The phenylpropanoid biosynthesis-related genes and a transcription factor VvERF003 were screened for possible involvement in ethylene-mediated flavonol biosynthesis by transcriptome sequencing. The role of VvERF003 was further proved to promote flavonol accumulation in the transient overexpression of grape fruits and leaves, and the upregulation of genes related to flavonol biosynthesis. Furthermore, VvERF003 promoted flavonol biosynthesis by directly binding to and activating the promoters of VvCHI1 and VvFLS1, and positively regulated their expression. These results indicated that VvERF003 was induced by ethylene and promoted the accumulation of flavonols in ‘Chardonnay’ grape berry skin by positively regulating the flavonol biosynthesis genes VvCHI1 and VvFLS1. Full article

The stress-associated proteins (SAPs) correspond to zinc-finger proteins containing A20/AN1 domains that are involved in plant responses to a wide range of biotic and abiotic stresses. However, in oat, no information has been available so far regarding the characteristics and regulation of these genes. In the current research work, eleven AvSAP genes were identified in oats genome (OT3098 variety) named AvSAP1 to AvSAP11. Eight proteins contained both A20 and AN1 domains located at the N- and C-terminal portions of the proteins, respectively. Subsequently, the gene structure and duplication, chromosomal location, cis-acting elements, and protein properties were analyzed using bioinformatic tools. Moreover, genes expression profiles revealed that AvSAP genes present hormones and stress-responsive cis-elements in their promoters. These observations were confirmed using QRT-PCR analysis. Indeed, the majority of identified AvSAP genes were responsive to NaCl, PEG, heat, ethylene, and metallic (Mn, Cu, and Cd) stresses. Moreover, ABA phytohormone induced a significant upregulation of nine AvSAP genes in leaves (5.8–6.5-fold induction) and roots (1.9–4.2-fold induction), corroborating their crucial role of those genes in plants’ response to a wide range of abiotic stresses. In contrast, GA and IAA exert a slight effect on those genes. Finally, AvSAP1 protein expression in bacterial cells conferred tolerance to ionic and osmotic stress. Our results provide deeper insight into AvSAP genes in plants and support advanced functional analyses of this gene family in oats. Full article

Background: Post-harvest losses in bananas, particularly due to diseases such as anthracnose and stem-end rot, significantly limit their storage life and marketability. Developing effective and non-toxic treatments to prolong the shelf life of fruits while maintaining quality is crucial inenabling long-distance transport and facilitating exports. Methods: The most popular and commercial banana variety, ‘Grand Naine’, was treated with a proprietary secondary metabolite-based formulation (this refers to a solution containing natural compounds produced by living organisms, which are not directly involved in growth but can influence various biological processes, such as antimicrobial activity) and stored under cold conditions at 13 °C, using vacuum packaging (a method where air is removed from the packaging to reduce spoilage and prolong freshness). Untreated fruits were considered as controls, meaning that they were not subjected to the treatment and served as a baseline for comparison. Shelf life-related parameters such as ethylene production (a plant hormone responsible for triggering fruit ripening), ACC oxidase activity (an enzyme central to ethylene synthesis), respiration rate (the rate at which fruit consumes oxygen and produces carbon dioxide), firmness, total soluble solids (TSS; measures the sugar content in fruit), acidity, and metabolic composition were assessed, including indices of susceptibility to disease. These measurements were taken at regular intervals for both treated and control fruits. Results: Secondary metabolite-treated bananas maintained quality for 45 days, staying free from anthracnose and stem-end rot. Control fruits showed over-ripening and an 11.6% percent disease index (PDI). Treated fruits had lower ethylene production (7.80 μg/kg/s vs. 10.03 μg/kg/s in controls), reduced ACC oxidase activity, and a slower respiration rate, delaying ripening. They also had greater firmness (1.45 kg/cm²), optimal TSS (13.5 °Brix), balanced acidity (0.58%), and increased flavonoid and antioxidant levels compared to controls. Conclusions: Secondary metabolite-based treatment, combined with cold storage and vacuum packaging, extended banana shelf life to 45 days, minimized disease, and preserved fruit quality. This approach substantially reduced post-harvest losses, demonstrating export potential through extended storage. Full article

Cold stress limits cucumber productivity, and grafting onto tolerant rootstocks offers a promising strategy for improving resilience. This study compared the responses of cucumber heterografts and self-grafts exposed to different cold temperatures, aiming to uncover the molecular basis of grafting-mediated tolerance. Morphological observations showed that grafting onto Cucurbita ficifolia and C. maxima X C. moschata cv. Tetsukabuto rootstocks improved plant growth under moderate cold, while extreme stress remained lethal. Transcriptome analysis revealed that heterografts displayed broader and more sustained differentially expressed genes than self-grafts. Gene ontology (GO) enrichment in heterografts indicated early activation of structural, regulatory, and metabolic processes, with continued enrichment at later stages. KEGG analysis highlighted plant hormone signaling as a central pathway modulated by heterografting, with selective regulation of auxin, ethylene, and ABA signaling. Heterografts activated key regulators, including MAPK3-like, TIFY5A, and CPK28, which were strongly expressed, alongside transcription factors from NAC, CAMTA, WRKY, and MYB families, suggesting coordinated regulation of cold-responsive networks. These results demonstrate that heterografting enhances cold tolerance by orchestrating multi-layered molecular responses, including hormone modulation, stress signaling, and transcriptional factors. This underscores the potential of grafting onto cold-tolerant rootstocks as a practical strategy for cucumber cultivation in cold-prone environments. Full article

Gray mold, caused by Botrytis cinerea, is a devastating disease of strawberry, with petal abscission rate (PAR) being a critical disease-avoidance trait. Rapid petal abscission removes a key infection site for the pathogen, thereby reducing disease incidence. To dissect the genetic basis of PAR, a segregating F₁ population was constructed from a cross between ‘Benihoppe’ (rapid abscission) and ‘Sweet Charlie’ (slow abscission). Utilizing BSR-Seq analysis of extreme bulks, five high-confidence quantitative trait loci (QTLs) were identified on chromosomes Fvb2-2, Fvb4-4, and Fvb6-3. These QTLs encompassed 672 candidate genes, with enrichment in “Plant hormone signal transduction” pathway. Integrated analysis of gene expression and SNPs identified 16 candidate genes, including those involved in flowering time (e.g., ELF3, HUA2 and AGL62) and plant hormone (e.g., ANT, RTE (ethylene), NDL2, FPF1 (auxin), and CYP707A7, ABF2 (abscisic acid) signaling, as well as calcium transport (ACA1, ECA3). Fourteen Kompetitive Allele-Specific PCR (KASP) markers were developed from candidate genes, with four markers showing significant correlations with PAR. This study provides the first genetic mapping of PAR in strawberry, revealing candidate genes and molecular markers that will facilitate the breeding of cultivars with improved gray mold resistance through enhanced petal abscission. Full article

The role of ethylene in the adaptation of Arabidopsis thaliana to salt stress induced by 150 mM NaCl is investigated. The responses of wild-type (Columbia, WT) plants and ethylene-insensitive etr1-1 mutants to short-term daily salt treatments were compared. Parameters analyzed included growth, water status, chlorophyll content, and hormone levels (ABA, IAA, cytokinins) using ELISA and immunohistochemistry. The results revealed that in the WT, salt stress induced hormonal redistribution: accumulation of ABA, IAA, and zeatin in shoots, accompanied by decreased ABA in the root tips and cytokinins in the whole roots. These hormonal changes were associated with stomatal closure, maintained leaf hydration, and inhibition of root growth. The inhibition of root growth may contribute to reduced uptake of toxic ions from the environment. In contrast, etr1-1 mutants exhibited no changes in hormonal status, failed to close stomata—leading to decreased leaf water content—and showed a sharp decline in chlorophyll content accompanied by suppressed shoot growth. The conclusions emphasize that ethylene sensitivity is essential for initiating adaptive hormonal rearrangements that coordinate growth and stomatal responses to mitigate the effects of salt stress. Full article

The AP2/ERF (APETALA2/ethylene-responsive factor) superfamily is one of the largest transcription factor families in plants and is not only vital for plant growth and development but also participates in responding to various abiotic stresses. However, few studies have investigated the function of the AP2/ERF gene family in natural rubber (NR) biosynthesis in Hevea brasiliensis. Here, 174 HbAP2/ERF genes were identified genome-wide and classified into 18 subclades based on gene-conserved structure and phylogenetic analysis. Gene duplication analysis revealed that 7 tandem and 100 segmental duplication events were major drivers of this gene family. Cis-element analysis in HbAP2/ERF promoters identified light-, hormone-, stress-, and development-associated cis-elements. Tissue-specific expression profiles revealed that 160 HbAP2/ERFs were expressed in at least one tissue. The protein–protein interaction network identified 59 potential interactions among the HbAP2/ERFs. Critically, dual-luciferase reporter assays confirmed that two key regulators exhibit distinct regulatory modes on NR biosynthesis-related genes: HbAP2/ERF25 significantly repressed the transcriptional activities of HbMVD1, HbCPT7, and HbSRPP1, whereas HbAP2/ERF46 repressed HbMVD1 but activated HbHMGR1, HbFPS1, and HbSRPP1. These findings reveal the complex regulatory network of HbAP2/ERFs in NR biosynthesis, establish a comprehensive framework for understanding their evolution and functional diversification, and provide novel molecular targets for genetic improvement of NR yield in rubber tree breeding and metabolic engineering. Full article

Nitrogen (N) uptake of managed turfgrasses in sand rootzones is of particular importance as it relates to reducing N leaching, reducing or maximizing N fertilizer applications, and optimizing overall plant quality. Two greenhouse experiments were conducted to determine if the inclusion of a one-time application of soil surfactant tank-mixed with ammonium sulfate fertilizer (FERT) improved fertilizer longevity and bermudagrass (Cynodon dactylon L. Pers. × C. transvaalensis Burtt-Davy, cv. ‘TifEagle’) quality (TQ), yield, leaf N content, N uptake (NUP), chlorophyll index (CI), and volumetric water content (VWC) under deficit irrigation. An untreated, fertilizer-only (Fert) (49 kg N·ha⁻¹), and non-ionic alkylpolyglycoside/ethylene oxide-propylene oxide (AEP) was tank-mixed with fertilizer at two rates, Fert+AEP(L) (1.17 L·ha⁻¹) or Fert+AEP(H) (1.75 L·ha⁻¹), to determine rate efficacy. In 2015, Fert and Fert+AEP(L) significantly increased TQ and CI, while in 2016, both AEP (L and H) significantly increased only TQ. VWC was significantly greater in untreated in 2015. At the end of the trials in 2015 and 2016, yield and NUP were significantly greater in Fert+AEP(H) and Fert+AEP(L), respectively, but leaf N content was not statistically significant between all fertilizer treatments. The role of surfactants in prolonging fertilizer effectiveness under deficit irrigation warrants further investigation. Full article

Soybean (Glycine max) is a globally important crop, but its productivity is often limited by suboptimal nodulation and nitrogen fixation, particularly under stress conditions. Bradyrhizobium diazoefficiens strain USDA110 is widely applied to enhance nodulation, yet its efficiency can be further improved by phytohormone modulation. This study examined the effects of seed coatings containing plant growth regulators (PGRs)—acetylsalicylic acid (ASA), aminoethoxyvinylglycine (AVG), Indole-3-butyric acid (IBA), and 6-benzylaminopurine (BAP)—at varying concentrations (5, 50, and 500 nM), in combination with USDA110, on nodulation, nitrogenase activity, ethylene emission, physiological traits, and yield of soybean cultivar CM60. Laboratory assays identified 50 nM AVG, 5 nM IBA, and 5 nM ASA as optimal treatments, significantly enhancing nodule number and nitrogenase activity more than 32% and 28%, as, respectively, compared to untreated seeds. Greenhouse trials in pots, both under well-watered and water stress conditions, showed that USDA110 + AVG/IBA significantly improved photosynthetic rate (+21 and +18% compared to USDA110 alone) and increased plant height. Notably, USDA110 + AVG/IBA treatments sustained higher seed weight under drought, increasing it by over 25%, indicating strong synergistic effects in mitigating stress impacts. These findings highlighted that integrating USDA110 with specific PGRs represented a promising strategy to optimize nitrogen fixation and enhanced soybean productivity under both favorable and challenging conditions. Full article