Search Results (5,326)

Drought and salinity are major abiotic stresses that severely constrain plant growth and agricultural productivity. Histidine kinases (HKs), as key components of the plant two-component system (TCS), play crucial roles in environmental signal perception and adaptive responses. In this study, we functionally characterized a sweet potato (Ipomoea batatas L.) HK gene, IbHK1a, and investigated its role in drought and salt stress tolerance. Expression analysis revealed that IbHK1a is predominantly expressed in root tissues, particularly in storage and fibrous roots, indicating its potential involvement in stress sensing and adaptation. Subcellular localization demonstrated that the IbHK1a protein is localized to the plasma membrane, suggesting a role in external signal perception. To elucidate its biological function, IbHK1a was heterologously overexpressed in Arabidopsis thaliana. Transgenic plants exhibited significantly enhanced tolerance to drought and salt stress, as evidenced by higher seed germination rates, improved primary root growth, reduced leaf wilting, and increased survival rates compared with wild-type (WT) plants. Physiological analyses showed that IbHK1a overexpression led to increased activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), accompanied by reduced accumulation of reactive oxygen species (ROS) such as hydrogen peroxide (H₂O₂) and malondialdehyde (MDA). Consistently, leaf histochemical staining confirmed lower ROS accumulation in transgenic plants under stress conditions. In sweet potato, overexpression of IbHK1a in transgenic hairy roots enhanced tolerance to drought and salinity, whereas RNA interference lines displayed increased sensitivity, further confirming its positive regulatory role. Additionally, protein interaction analysis indicated that IbHK1a interacts with Arabidopsis histidine phosphotransferase proteins (AHPs), suggesting its involvement in conserved TCS-mediated phosphorelay signaling pathways. Functional complementation analysis demonstrated that IbHK1a partially rescues the stress-sensitive phenotype of the AHK1 mutant, indicating functional conservation with Arabidopsis AHK1. Collectively, these findings demonstrate that IbHK1a positively regulates drought and salt stress tolerance by enhancing antioxidant defense and ROS homeostasis. Its interaction with AHPs and partial complementation of the ahk1 mutant further support its involvement in the conserved TCS phosphorelay pathway. These results establish IbHK1a as an important component of abiotic stress responses and a potential genetic target for improving drought and salinity tolerance in sweet potato. Full article

Plateau environments are characterized by low temperatures, intensive radiation and drastic diurnal temperature fluctuations, all of which greatly suppress rooting and seedling establishment of tea chrysanthemum cuttings. To compare the regulatory effects of different rooting regulators on tea chrysanthemum cuttings under plateau cultivation conditions, this study conducted a 60-day plug-tray cultivation experiment from late July to late September with three biological replicates. All the cuttings, including the IBA-pre-treated control (CK), were uniformly pretreated with 500 mg·L⁻¹ indole-3-butyric acid (IBA). On this basis, four treatments, including 5-aminolevulinic acid hydrochloride (5-ALA, T1), γ-aminobutyric acid (GABA, T2), Bacillus amyloliquefaciens (T3) and Bacillus velezensis (T4), were applied to determine root morphology, seedling growth, physiological stress metabolism, photosynthetic capacity and rhizosphere substrate characteristics. The different rooting promoters exerted distinct regulatory effects on cutting performance. The GABA treatment significantly improved leaf gas exchange, seedling growth, antioxidant status and rhizosphere nutrient conditions, with net photosynthetic rate, stomatal conductance and transpiration rate improved by 316.34%, 92.31% and 168.00%, respectively, and significantly increased seedling vigor index, plant height and stem diameter by 21.74%, 60.85% and 46.08%, respectively. It also elevated the soluble sugar content and the ascorbate peroxidase (APX) activity, reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, and optimized rhizosphere available nitrogen and phosphorus levels, as well as related enzyme activities. Nevertheless, the 5-ALA treatment exhibited unique advantages in improving rooting rate and seedling survival. Mantel tests confirmed that the seedling vigor index closely correlated with the root architecture, the total chlorophyll and the transpiration rate. A principal component analysis (PCA) and a cluster heatmap both identified GABA as the treatment with relatively balanced overall performance. A comprehensive D-value evaluation ranked the treatments as GABA > B. amyloliquefaciens > 5-ALA > B. velezensis > control. The treatment with 5-ALA mainly improved the antioxidant capacity, the B. amyloliquefaciens treatment favored root elongation and total nutrients, and the B. velezensis treatment only produced mild improvements. This study indicates that the different exogenous regulators target divergent growth and physiological processes, and the GABA treatment could coordinately boost root development, photosynthetic performance, antioxidant defense and rhizosphere nutrient cycling, thus presenting great application potential for tea chrysanthemum cutting propagation under plateau cultivation conditions. Full article

Botanical gardens are highly heterogeneous plant systems characterized by high taxonomic diversity, with numerous plant taxa represented within confined areas, and complex ecological interactions that create unique challenges for pest management. Conventional IPM strategies, designed for simplified agroecosystems, often fail to address complex pest pressures in curated environments. Microbial biostimulants have emerged as promising components of sustainable IPM strategies by enhancing plant defense responses, improving stress resilience, and reducing reliance on chemical inputs. This review synthesizes current knowledge on microbial biostimulants, including plant growth-promoting rhizobacteria, arbuscular mycorrhizal fungi and endophytic microorganisms, in modulating plant defense against insect herbivores. These beneficial microbes enhance plant resistance through multiple mechanisms. They activate induced systemic resistance and modulate key phytohormones, including jasmonic acid, salicylic acid, and ethylene. Additionally, they regulate calcium-dependent and reactive oxygen species-mediated defenses. Microbially induced changes in plant secondary metabolites and volatile organic compounds further influence herbivore behavior and trophic interactions. Emphasis is placed on integrating microbial biostimulants into IPM frameworks tailored to botanical gardens. This highlights compatibility with biological control agents and reduced reliance on synthetic pesticides. Despite promising advances, challenges remain, including context-dependent efficacy, host specificity and limited long-term validation. Overall, microbial biostimulants offer a promising tool for enhancing IPM in biodiversity-rich botanical gardens, although further long-term validation is needed to fully assess their sustainability and effectiveness. Full article

The degradation of Calcisols in the arid regions of Central Asia constrains sustainable agricultural production because of low organic matter content, poor aggregate stability, nutrient limitations, and increasing climatic stress. This study evaluated a rhizosphere engineering approach based on the native plant growth-promoting bacterium Pseudomonas veronii Ps-S/Sh-1503/2022 for the rehabilitation of degraded Calcisols. Four-year field experiments (2022–2025) using Sorghum bicolor assessed plant growth, rhizosphere microbial indicators, physiological responses, pathogen suppression, crop productivity, and implementation feasibility through economic and environmental assessments. Inoculation with P. veronii increased root depth by 45%, improved aboveground biomass, increased the ratio of culturable bacteria to Fusarium spp. from 6.1 to 10.3, and reduced Fusarium abundance by 29.4%. Structural equation modeling suggested that trophic support (42.1%), aggregate stabilization (27.4%), biocontrol (23.3%), and defense-related responses (7.2%) were the principal pathways associated with soil rehabilitation. Economic assessment indicated that the combined inoculation and mineral fertilization treatment provided the highest profitability, while environmental assessment estimated potential reductions in mineral fertilizer use and greenhouse gas emissions. These findings suggest that rhizosphere engineering using a native P. veronii strain represents a promising, economically viable, and climate-smart approach for improving the biological functioning of degraded Calcisols and supporting sustainable agricultural production. Full article

Soybean (Glycine max (L.) Merr.) was originally domesticated in China and is a kind of significant leguminous crop, which can fix atmospheric nitrogen to bioavailable nitrogen in association with rhizobia. Ceramides, intermediates of sphingolipids, are crucial structural components in membrane formation and also function as signaling molecules, which play crucial roles in plant development and defense. Although Arabidopsis ceramide synthase genes AtLOH1 and AtLOH3 overexpression plants increased biomass compared to the wild type, the potential mechanism in plant growth was still unclear. A soybean ceramide synthase gene 1 (GmCS1) has a high expression level in the stem, and the protein is localized in the endoplasmic reticulum. Overexpression of GmCS1 promotes soybean lateral branch development for effective branch formation, significantly increasing the number of lateral branches and pods. Using transcriptomic profiles, we found that GmCS1 overexpression lines displayed the upregulation of plant hormone signal transduction pathway gene expression in developmental branches. Actually, Indole-3-acetic acid (IAA) induces bud outgrowth rather than initiation according to the determination of endogenous IAA and cytokinin (CKs) in soybean lateral branches. Collectively, these results suggest that GmCS1 may be a functional ceramide synthase gene in soybean, with the GmCS1-mediated regulatory network playing a crucial role in controlling branch development by IAA and CKs homeostasis. Exploring the regulation mechanisms by GmCS1 overexpression lines is essential for Ideal Soybean Architecture (ISA) innovation. Full article

Microorganism inoculants are becoming increasingly essential in sustainable agriculture because they improve nutrient availability, promote plant growth, inhibit disease, and increase crop tolerance to environmental stresses. Nonetheless, their field performance is frequently hampered by poor storage survival, low rhizosphere establishment, and susceptibility to harsh climatic conditions. Encapsulation technologies provide an effective solution by encapsulating microbial cells in a biodegradable matrix, extending shelf life, increasing vitality, and allowing for controlled release in the soil. This review focuses on four agriculturally significant microorganisms: Azotobacter chroococcum, Azospirillum brasilense, Pseudomonas brassicacearum, and Trichoderma harzianum. Their modes of action, including nitrogen fixation, phytohormone synthesis, pathogen inhibition, and stimulation of plant defense responses, are reviewed alongside recent advances in encapsulation strategies. Alginate-based formulations and proposed potential multi-species microbial consortia are discussed as promising strategies for improving inoculant performance. However, the successful development of multifunctional potential microbial formulations requires further investigation of microbial compatibility, formulation stability, synchronized release behaviour, and long-term storage performance before broad agricultural implementation can be achieved. Full article

Amorphophallus spp., valued as both crops and medicinal plants, are highly susceptible to soft rot disease, causing substantial yield and economic losses during cultivation and storage. Calcium nanoparticle (CaNP) fertilizer not only has the potential to enhance crop yields but also plays a crucial role in the control of crop pests and diseases. However, its application in the control of soft rot disease in konjac has not yet been investigated. In this study, the antibacterial efficacy of CaNP fertilizer against the typical soft rot pathogen P. aroidearum MY11 in Amorphophallus konjac (A. konjac) was investigated. It was found that CaNP fertilizer significantly inhibited the growth, motility ability and the activity of cell wall-degrading exoenzymes of P. aroidearum MY11. Transmission electron microscopy revealed that the morphology of bacterial cells treated with CaNPs did not change significantly, but significant particle deposition was observed within the cells. Furthermore, CaNPs pretreatment could reduce the reactive oxygen species (ROS) content, activate the antioxidant enzyme system, and enhance the photosynthetic capacity of A. konjac plants. qRT-PCR analysis revealed that CaNPs pretreatment might enhance the resistance of A. konjac plants to the soft rot pathogen MY11 by activating the jasmonic acid (JA), salicylic acid (SA) signaling pathway and the cell wall stress response pathway. This research provides a new candidate for nanopesticides that can be used to control the bacterial soft rot disease of konjac. Full article

Purple celery (Apium graveolens L.) is a high-value functional vegetable rich in anthocyanins, but achieving a balanced optimization between biomass accumulation and nutritional quality in plant factories remains challenging due to species-specific spectral trade-offs, and current research lacks integrated light recipes that simultaneously optimize photosynthetic efficiency, antioxidant defenses, and functional quality while suppressing nitrate accumulation. This study evaluated five LED treatments over 30 days: white light (CK), monochromatic red (R), and red-to-blue photon flux density ratios of 5:5, 7:3, and 8:2. Red light induced stem elongation but suppressed root development. Conversely, 8R2B delivered the best performance, significantly elevating leaf, petiole, root, and total fresh biomass and increasing total dry weight by 68.8% over CK. It also markedly enhanced chlorophyll a, b, total chlorophyll, and carotenoids, as well as improved PSII quantum yield (YII), photochemical quenching (qP), and electron transport rate (ETR), while reducing non-photochemical heat dissipation (NPQ) by 61.0%, indicating superior light-use efficiency. Furthermore, 8R2B upregulated CAT and POD activities promoted soluble sugars (up 688.4% in leaves), soluble proteins, and ascorbic acid accumulation, yet reduced leaf nitrate by 28.5%. Principal component analysis confirmed 8R2B as the most effective formulation across all growth, photochemical, defense, and quality traits. These findings provide a novel, evidence-based 8:2 red-to-blue LED light recipe for high-yield, high-quality, and commercially viable purple celery production in controlled environment agriculture. Full article

Soil yeasts represent a significant component of the agricultural microbiota and possess high ecological and biotechnological potential in production systems such as those for sugarcane. This review analyses the importance of these microorganisms in fundamental processes related to soil health and functionality, highlighting their role in nutrient cycling, the decomposition of organic matter, and the availability of essential elements for plant uptake. Numerous studies have shown that certain yeasts possess plant-growth-promoting characteristics, including the production of phytohormones, siderophores and compounds capable of solubilizing nutrients, thereby promoting plant development and the sustainability of the agroecosystem. Furthermore, this review highlights the potential of yeasts as agents for the biological control of agricultural diseases and pests. Various mechanisms of action are described, including the production of volatile organic compounds, hydrolytic enzymes, antagonistic toxins, competition for nutrients and space, and the induction of defense responses in plants. In sugarcane systems, some yeast species such as Metschnikowia spp., Meyerozyma guilliermondii, Wickerhamomyces anomalus, Pichia spp., and Rhodotorula glutinis have demonstrated antagonistic activity against plant pathogens and the potential to be integrated into sustainable agricultural management strategies. Full article

Soil salinization stands out as a major factor contributing to the shrinkage of arable land. This study explored the salt tolerance mechanism of tillers in CMG and 9311 by evaluating morphophysiological, transcriptomic, and metabolomic characteristics under 0.3% NaCl stress. The activities of SOD, POD, and APX in the tiller nodes of the salt-tolerant variety CMG were higher than those of 9311, while the levels of MDA and hydrogen peroxide in the tiller nodes of CMG were relatively low. Both varieties responded to salt stress mainly by activating pathways such as amino acid metabolism (alanine, aspartic acid, glutamic acid metabolism, and arginine biosynthesis), amino acid acyl-trNA biosynthesis, oxidative phosphorylation, and phenylpropanin biosynthesis. The varieties differed in that CMG tillering nodes also have unique pathways of “glycerophospholipid metabolism” (related to membrane lipid remodeling) and “biosynthesis of the cuticle, suppositories and waxes”, which can effectively reduce water loss and prevent sodium ions from entering. In addition, CMG can regulate more plant hormone signaling pathways to coordinate the expression and metabolic activities of downstream defense genes, such as abscisic acid (ABA) and jasmonic acid (JA), and other hormone signals. After salt stress, the CMG tiller nodes tend to strengthen themselves, enabling them to resist stress and reduce Na⁺ toxicity, while the 9311 tiller nodes, under the condition of activating basal metabolism, transfer to the leaves to enhance photosynthetic efficiency and resist stress. Through comprehensive screening and analysis of the genes and metabolites of CMG and 9311 tillers under salt stress, the molecular mechanisms and metabolic pathway dynamics involved in their salt stress response were identified, thus providing a new perspective for in-depth research on rice salt tolerance mechanisms. Full article

Rose rosette virus (RRV) causes witches’ broom disease in roses. This study examined whether differences in disease in these spatially distinct domains are associated with local changes in defense-related hormones and transcriptional reprogramming. The levels of defense-related phytohormones salicylic acid (SA), jasmonic acid (JA), 9-lipoxygenase (9-LOX), 13-lipoxygenase (13-LOX), and derived oxylipins were different in these distinct tissues. We curated differentially expressed genes involved in the biosynthesis, storage, and signaling of SA, JA, and oxylipins to reveal how specific defense pathways correlate with these distinct disease states. Gene ontology (GO) analysis and the Disease Resistance Analysis and Gene Orthology 3 (DRAGO3) pipeline revealed stress-associated genes and classical resistance (R) gene families that were differently expressed in these distinct tissue domains. Promoter analysis of defense-associated transcription factors and histone modifiers revealed hormone responsive elements, suggesting complex hormone crosstalk is involved in defense-related gene expression. We confirmed by RT-qPCR, a notable subset of defense genes in the chromosome 5 hotspot, specifically in the linkage group 5 (LG5) quantitative trait loci, linked to reduced RRV susceptibility, was altered in both field-infected and greenhouse-inoculated plants. The association of high versus low disease states with distinct defense hormone signatures and gene expression patterns suggests that local immune states, rather than whole-plant defenses, determine whether a cane becomes rosetted or remains asymptomatic. Full article

As green consumption becomes mainstream, deceptive marketing in the food industry poses a significant threat to the sustainability of food systems. This study aimed to investigate how consumers’ psychological decision-making mechanisms and food choices are influenced by corporate greenwashing. This study utilized a quantitative cross-sectional design, integrating environmental cognition, greenwashing perception, and brand trust into an extended Theory of Planned Behavior (TPB) framework. Survey data collected from 445 respondents in Taiwan, using a fictional plant-based food (oat milk) brand as a scenario stimulus, were analyzed using structural equation modeling (SEM). The findings reveal that environmental knowledge and awareness significantly enhance greenwashing perception, which significantly diminishes brand trust, thereby diminishing positive sustainable food choices. Notably, environmental awareness positively moderated the relationship between greenwashing perception and brand trust. Furthermore, the interaction between perceived behavioral control and attitude toward food choices was not significant, demonstrating that emotional rejection substantially outweighs rational evaluation when faced with food-related deception. This study re-examines the rational assumptions of the traditional TPB, revealing that moral defense mechanisms play a central role in consumer food choices. From a practical perspective, the findings urge food enterprises to shift from symbolic green marketing to high transparency, which is essential for restoring brand trust and avoiding consumer boycotts. Full article

The successful use of Assisted Reproductive Technologies (ARTs) such as artificial insemination (AI) in small ruminants and other mammals depends on many factors, the most important of which is the quality of the semen used. The liquid storage and cryopreservation of spermatozoa at lower temperatures are associated with artificial insemination and rapid genetic improvement programs in the sheep production industry. Several studies have reported increased lipid peroxidation (LPO) and highly reactive oxygen species (ROS) production during liquid storage or cryopreservation of ram semen, leading to oxidative stress (OS), decreased antioxidant defense, and changes in sperm quality parameters like biokinetic and biochemical characteristics, viability, functional membrane and DNA integrity, along with mitochondrial activity. Therefore, supplementing ram semen extenders with exogenous antioxidants before preservation could mitigate this harmful effect. Various in vitro studies have reported improvements in ram sperm quality parameters like motility indexes, vitality, functional membrane/DNA integrity, antioxidant enzyme activity, total antioxidant content, mitochondrial activity, in vivo/in vitro fertility with significant decline in sperm abnormality, free radical production, LPO, ROS, apoptosis rate, and cytochrome C release from the mitochondrial matrix after the addition of various natural and synthetic antioxidant (vitamins, glutathione, taurine, pyruvate, melatonin, cysteine, selenium, zinc, plant extracts, sugars, amino acids, polyphenols) substances during preservation. Therefore, this review summarizes recent findings on oxidative stress-induced damage to sperm quality parameters in various ram breeds during chilling storage and cryopreservation. Moreover, supplementing basic semen extenders with different non-enzymatic antioxidant substances as a method to maintain sperm quality—along with their efficacy in reducing or preventing sperm damage during preservation—was discussed in detail. Full article

Spot blotch has become a major devastating disease in wheat. In the current study, Faisalabad-08 was supplemented with various levels of selenium (Se) both in vitro and in greenhouse experiments (CRD, n = 3) to counter the spot blotch pathogen. The results revealed that minimum disease incidence was assessed in the case of T₂ (50 mg L⁻¹). However, maximum plant growth attributes, including plant height (PH), plant fresh weight (PFW), plant dry weight (PDW), leaf surface area (LSA), and root length (RL), were recorded in T₅ (50 mg L⁻¹ + pathogen). Similarly, chlorophyll a, chlorophyll b, total chlorophyll, membrane stability index, carotenoid, relative water contents, proline, sugar, flavonoid, total phenolic content, SOD, POD, CAT, PPO, and PAL contents were enhanced in T₅ compared to other tested treatments. However, MDA, an oxidative damage marker, was significantly decreased with T₅. Correlation, PCA, and heatmap analysis suggested that all the attributes were significantly interrelated, except MDA, in defining the crop’s potential to sustain its growth under biotic stress. In crux, foliar Se application (50 mg L⁻¹) effectively mitigates spot blotch through enhanced antioxidant defense and physiological homeostasis. This sustainable approach offers a viable alternative to conventional fungicides for integrated wheat disease management. Full article

Populus hopeiensis is an important native poplar species in northern China, but herbivorous insect damage seriously affects its growth and ecological function. WRKY transcription factors play important roles in plant stress responses; however, the function of WRKY23 homologs in woody plant resistance to chewing herbivores remains unclear. In this study, a herbivore-responsive WRKY transcription factor gene, PhWRKY23, was identified from P. hopeiensis. PhWRKY23 expression was significantly induced by Spodoptera litura feeding, with a maximum increase of approximately 69.71-fold the control level at the highest damage level, and the encoded protein was predominantly localized in the nucleus. To investigate its function, PhWRKY23-overexpressing and RNA interference transgenic lines were generated. In the choice feeding assay, the consumed leaf area of PhWRKY23-overexpressing plants was approximately 85.5% lower than that of WT plants after 8 h. In the no-choice feeding assay, the total larval mass after 6 d was approximately 38.8% lower in larvae fed on overexpression plants and 51.0% higher in larvae fed on RNAi plants than in those fed on WT plants. Physiological analysis showed that RNAi plants accumulated significantly more MDA than WT and overexpression plants, whereas overexpression plants had higher chlorophyll a, chlorophyll b, and carotenoid contents than the other genotypes. Phytohormone analysis further showed that PhWRKY23-overexpressing plants accumulated higher levels of jasmonic acid, jasmonoyl-L-isoleucine, and salicylic acid, whereas abscisic acid showed no significant difference among genotypes. Yeast two-hybrid screening identified several candidate PhWRKY23-interacting proteins, and pairwise validation confirmed that PhWRKY23 interacted with PhDOX1 in yeast. These results indicate that PhWRKY23 positively contributes to herbivore resistance in P. hopeiensis and that this resistance phenotype is associated with changes in JA, JA-Ile, and SA accumulation and defense-related physiological traits. Full article