Search Results (181)

Blue fescue (Festuca glauca) is a widely used ornamental grass worldwide. Drought is an important limiting factor for the growth and development of blue fescue; therefore, cultivating new strains of blue fescue with a strong drought tolerance is of great significance for its production practice. To investigate the drought tolerance mechanism of ds-1, this study subjected both ds-1 and “Festina” to a natural drought treatment and measured their physiological and biochemical indicators. A transcriptomic analysis was also conducted to explore the underlying molecular mechanisms. The results showed that, after the drought treatment, the relative water content (RWC), water use efficiency (WUE), and photosynthetic rate (Pn) of ds-1 leaves were significantly higher than those of “Festina”; in addition, the contents of H₂O₂ and O₂⁻, the relative electrical conductivity (REC), the malondialdehyde (MDA) content, the gas conductance (Gs), and the transpiration rate (Tr) were significantly lower than those of “Festina”. The peroxidase (POD) activity of ds-1 was significantly higher than that of “Festina”, while the superoxide dismutase (SOD) activity of ds-1 was significantly lower than that of “Festina”. The transcriptome data analysis showed that there were a total of 9475 differentially expressed genes (DEGs) between ds-1 and “Festina”. A Venn plot analysis showed 692 DEGs between ds-1—8d vs. “Festina”—8d and ds-1—16d vs. “Festina”—16d. A KEGG enrichment analysis showed that these 692 genes were mainly enriched in 86 pathways, including those related to the photosynthesis antenna protein, plant hormone signal transduction, MAPK signaling, starch and sucrose metabolism, and arginine and proline metabolism. Further screening identified genes that may be associated with drought stress, including PYL, PP2C, SnRK2, ABF, BRI1, JAZ, MYC2, Lhc, and MPK6. The qRT-PCR results indicated that the expression trends of the DEGs were consistent with the transcriptome sequencing results. Our research results can provide a basis for exploring candidate genes for drought tolerance in blue fescue. In addition, our research results provide valuable genetic resources for the development of drought-resistant ornamental grass varieties, which can help reduce water consumption in cities and decrease labor and capital investment. Full article

(1) Objective: The biosynthesis of medicinal secondary metabolites in Dendrobium nobile Lindl. is regulated by complex environmental, hormonal, and microbial interactions. However, the mechanisms by which subtle variations in plant elevation shape metabolite accumulation through plant–microbe–hormone networks remain largely unexplored. (2) Methods: We conducted a multi-omics investigation of D. nobile cultivated under simulated wild conditions at four elevation gradients (347–730 m) in Chishui, China. High-throughput transcriptome sequencing and ITS-based fungal community profiling were combined with hormone quantification and functional prediction (FUNGuild), enabling integrated analysis of hormone pathway activation, microbial structure–function dynamics, and dendrobine levels. (3) Reults: This study systematically investigated D. nobile cultivated under simulated wild conditions across four elevation gradients (347–730 m) in the Danxia region of Chishui, China. We identified a dual regulatory mechanism underlying the elevation-dependent accumulation of dendrobine alkaloids, involving both plant hormone signaling and endophytic fungal communities. Transcriptomic analyses revealed coordinated upregulation of key hormone pathway genes, including DELLA, PYR/PYL, SnRK2, COI1-JAZ-MYC2, and NPR1-TGA, particularly in CY01Y samples at 670 m elevation from ChiYan base in Chishui city, which corresponded to the highest dendrobine content. Concurrently, functional prediction of the ITS-based fungal sequencing data revealed that CY01Y harbored a stable, functionally enriched fungal community dominated by saprotrophs, fungal parasites, and plant pathogens. (4) Conclusions: Through integrative hormone profiling, gene expression, and microbial function analysis, we propose that elevation-induced environmental cues reshape hormone pathways both directly and indirectly via microbial feedback. Specific microbial taxa were identified as potential modulators of hormone signaling and secondary metabolism. The coordinated interaction between plant hormones and endophytic fungi supports a hormone–microbiome–metabolite network that dynamically regulates dendrobine biosynthesis in response to micro-elevation variation. Full article

Background/Objectives: Carotenoids in citrus are vital nutritional compounds and precursors of the stress hormone abscisic acid (ABA). SNF1-related kinases (SnRKs)—key regulators of plant stress signaling that phosphorylate is targeting proteins for post-transcriptional regulation—mediate ABA signaling through its subfamily SnRK2-phosphatase type-2C (PP2C)-PYR1-LIKE (PYL) cascades. This study aims to identify the SnRK-PP2C-PYL family members and decipher their underlying post-transcriptional regulatory mechanisms which control carotenoid metabolism in Citrus sinensis for improved nutrition and stress resilience. Methods: SnRK, PP2C, and PYL were identified by integrated HMMER-blastp-CDD pipeline in the Citrus genome. Using two carotenoid-divergent cultivars, ‘Newhall’ (yellow) and ‘Cara Cara’ (red, hyperaccumulating linear carotenoids), we conducted spatiotemporal expression profiling and integrated transcriptomic and metabolomic data via Weighted Gene Co-expression Network Analysis (WGCNA) to identify modules correlated with accumulation. Results: We identified 26 CsSnRKs (1 SnRK1, 7 SnRK2, 18 SnRK3), 57 CsPP2Cs, and 7 CsPYLs in Citrus sinensis. Despite a >26-fold difference in linear carotenoids, structural gene expression was similar among cultivars, strongly implicating post-transcriptional control. WGCNA identified a key turquoise module highly correlated with linear carotenoid content. This module contained phosphorylation-related genes (CsSnRK1/3.5/3.6/3.16, CsPP2C14/15/33/35/38/40/43/56, and CsPYL6), biosynthetic genes (CsPSY1, CsZISO, and CsZDS), and candidate transcription factors. Network analysis predicted that CsSnRKs, CsPP2Cs, and CsPYLs regulate phytoene-derived carotenoid biosynthesis. Conclusions: We propose a novel phosphorylation-mediated post-transcriptional regulatory network in carotenoid accumulation. This mechanism bridges ABA signaling and metabolic adaptation, providing crucial molecular targets for engineering nutrient-dense and climate-resilient citrus varieties. Full article

Climate change is intensifying the co-occurrence of drought and heat stresses, which substantially constrain global crop yields and threaten food security. Developing climate–resilient crop varieties requires a comprehensive understanding of the physiological and molecular mechanisms underlying combined drought–heat stress tolerance. This review systematically summarizes recent advances in integrating multi-scale remote-sensing phenomics with multi-omics approaches—genomics, transcriptomics, proteomics, and metabolomics—to elucidate stress response pathways and identify adaptive traits. High-throughput phenotyping platforms, including satellites, UAVs, and ground-based sensors, enable non-invasive assessment of key stress indicators such as canopy temperature, vegetation indices, and chlorophyll fluorescence. Concurrently, omics studies have revealed central regulatory networks, including the ABA–SnRK2 signaling cascade, HSF–HSP chaperone systems, and ROS-scavenging pathways. Emerging frameworks integrating genotype × environment × phenotype (G × E × P) interactions, powered by machine learning and deep learning algorithms, are facilitating the discovery of functional genes and predictive phenotypes. This “pixels-to-proteins” paradigm bridges field-scale phenotypes with molecular responses, offering actionable insights for breeding, precision management, and the development of digital twin systems for climate-smart agriculture. We highlight current challenges, including data standardization and cross-platform integration, and propose future research directions to accelerate the deployment of resilient crop varieties. Full article

As a key economic tree in southern China, Camellia oleifera faces severe yield losses under drought. Grafting onto drought-tolerant rootstocks offers a potential mitigation strategy. To elucidate the impact of rootstocks on the drought resistance of the superior Camellia oleifera Abel. cultivar “Xianglin 210”, grafted seedlings with five scion–rootstock combinations, were subjected to gradient drought stress. Key physiological and biochemical indices related to photosynthesis, antioxidant enzymes, and osmotic adjustment were measured. Drought resistance was comprehensively evaluated using membership function analysis, and the expression of stress-responsive genes was quantified via quantitative real-time PCR (qRT-PCR). The results demonstrated that under drought stress, (1) stomatal conductance (Gs) decreased by 31.2–48.7%, while instantaneous water use efficiency (WUE) increased by 18.5–35.4%; (2) proline (Pro) and soluble sugars (SS) accumulated significantly, with increases of 2.3–4.1-fold and 1.8–3.2-fold, respectively; (3) activities of antioxidant enzymes were enhanced by 56–127%, mitigating oxidative damage; (4) membership function analysis ranked drought resistance as follows: Xianglin 27 (0.812) > Guangxi Superior Germplasm (0.698) > C. yuhsienensis (0.654) > Hunan Superior Germplasm (0.591) > Xianglin 1 (0.523); (5) qRT-PCR revealed significant upregulation of ABA signaling pathway genes (CoPYL6, CoPP2C75/51/24/26, CoSnRK2.8, and CoABI5) and transcription factors (CoLHY and CoWRKY70), indicating activation of drought-responsive regulatory networks. These findings provide a theoretical foundation for selecting drought-tolerant rootstocks and optimizing cultivation practices in Camellia oleifera, and provide practical criteria for selecting drought-tolerant rootstocks, facilitating sustainable Camellia oleifera cultivation in water-limited regions. Full article

SnRK kinases, central regulators of plant stress response, remain uncharacterized in Taxus—an ancient gymnosperm valued for paclitaxel production. This study aimed to identify the Taxus SnRK family and elucidate its functional roles. Specifically, we identified SnRK genes through genomic analysis and assessed tissue-specific expression via transcriptomics, while regulatory networks were deciphered using WGCNA. To overcome experimental constraints, a PEG-mediated protoplast transient expression system was developed using calli, followed by dual-luciferase assays. Consequently, 19 SnRK genes (2 SnRK1, 4 SnRK2, 13 SnRK3) were identified, with tissue-specific expression revealing TaSnRK1.2 upregulation under methyl jasmonate (MeJA) and in stress-resilient tissues (bark/root). Subsequently, WGCNA uncovered a bark/root-specific module containing TaSnRK1.2 with predicted TF interactions (TaGRAS/TaERF). Critically, homologous dual-luciferase assays demonstrated TaSnRK1.2 activates TaGRAS and TaERF promoters (4.34-fold and 3.11-fold induction, respectively). This study establishes the Taxus SnRK family and identifies TaSnRK1.2 as a hub integrating stress signals (e.g., MeJA) to modulate downstream TF networks, while the novel protoplast system enables future functional studies in this medicinal plant. Full article

The worldwide agriculture industry is facing increasing problems due to rapid population increase and increasingly unfavorable weather patterns. In order to reach the projected food production targets, which are essential for guaranteeing global food security, innovative and sustainable agricultural methods must be adopted. Conventional approaches, including traditional breeding procedures, often cannot handle the complex and simultaneous effects of biotic pressures such as pest infestations, disease attacks, and nutritional imbalances, as well as abiotic stresses including heat, salt, drought, and heavy metal toxicity. Applying phytohormonal approaches, particularly those involving hormonal crosstalk, presents a viable way to increase crop resilience in this context. Abscisic acid (ABA), gibberellins (GAs), auxin, cytokinins, salicylic acid (SA), jasmonic acid (JA), ethylene, and GA are among the plant hormones that control plant stress responses. In order to precisely respond to a range of environmental stimuli, these hormones allow plants to control gene expression, signal transduction, and physiological adaptation through intricate networks of antagonistic and constructive interactions. This review focuses on how the principal hormonal signaling pathways (in particular, ABA-ET, ABA-JA, JA-SA, and ABA-auxin) intricately interact and how they affect the plant stress response. For example, ABA-driven drought tolerance controls immunological responses and stomatal behavior through antagonistic interactions with ET and SA, while using SnRK2 kinases to activate genes that react to stress. Similarly, the transcription factor MYC2 is an essential node in ABA–JA crosstalk and mediates the integration of defense and drought signals. Plants’ complex hormonal crosstalk networks are an example of a precisely calibrated regulatory system that strikes a balance between growth and abiotic stress adaptation. ABA, JA, SA, ethylene, auxin, cytokinin, GA, and BR are examples of central nodes that interact dynamically and context-specifically to modify signal transduction, rewire gene expression, and change physiological outcomes. To engineer stress-resilient crops in the face of shifting environmental challenges, a systems-level view of these pathways is provided by a combination of enrichment analyses and STRING-based interaction mapping. These hormonal interactions are directly related to the United Nations Sustainable Development Goals (SDGs), particularly SDGs 2 (Zero Hunger), 12 (Responsible Consumption and Production), and 13 (Climate Action). This review emphasizes the potential of biotechnologies to use hormone signaling to improve agricultural performance and sustainability by uncovering the molecular foundations of hormonal crosstalk. Increasing our understanding of these pathways presents a strategic opportunity to increase crop resilience, reduce environmental degradation, and secure food systems in the face of increasing climate unpredictability. Full article

Soil salinization threatens agriculture by inducing osmotic stress, ion toxicity, and oxidative damage. SnRK2 genes are involved in plant stress responses, but their roles in salt stress response regulation of tobacco remain unclear. Through genome-wide analysis, we identified 54 SnRK2 genes across four Nicotiana species (N. tabacum, N. benthamiana, N. sylvestris, and N. tomentosiformis). Phylogenetic reconstruction clustered these genes into five divergent groups, revealing lineage-specific expansion in diploid progenitors (N. tomentosiformis) versus polyploidy-driven gene loss in N. tabacum. In silico promoter analysis uncovered regulatory networks involving light, hormones, stress, and developmental signals, with prevalent ABA-responsive elements (ABREs) supporting conserved stress-adaptive roles. Structural analysis highlighted functional diversification through variations in intron–exon architecture and conserved kinase motifs. This study provides a genomic atlas of SnRK2 evolution in Nicotiana, offering a foundation for engineering salt-tolerant crops. Full article

Saline–alkali stress severely inhibited potato growth, yield, and quality, and exogenous abscisic acid (ABA) played an important role in plant stress resistance. In this study, potato tissue culture seedlings were used as experimental materials, the control group was cultured in the MS medium without adding any substances, and the treatment group was cultured in MS medium supplemented with 50 mmol/L NaHCO₃ or 50 mmol/L NaHCO₃ + 38 µM ABA, respectively. To explore the effect of exogenous ABA on the biological characteristics of potato plants under saline–alkali stress, a genetic improvement strategy was designed based on PP2C (PGSC0003DMT400046381), a key gene of the ABA signaling pathway. The results showed that saline–alkali stress led to leaf greening, wilting, and root development stunting, while exogenous ABA treatment significantly alleviated stress damage. PP2C negatively regulates ABA signaling. SnRK2s are activated when PP2Cs are inactivated during the ABA response. Compared with wild-type CK, it was found that TG lines had increased SOD and POD activities, increased carotenoid and ABA contents, reduced the increase in Na⁺ content and the decrease in K⁺ content, and interfered with PP2C (PGSC0003DMT400046381) to significantly enhance potato salinity–alkali resistance. This study provides a theoretical basis and technical path for the analysis of ABA-mediated plant stress resistance mechanism and the breeding of potato stress resistance varieties. Full article

The WRKY transcription factor family is a significant family of plant transcription factors (TFs). Plant growth and development are often influenced by abiotic factors, such as salinity and low temperature. Numerous studies have demonstrated that WRKY TFs primarily influence plant responses to adversity. However, there are few studies on the role of WRKY genes in the stress responses of Malus baccata (L.) Borkh. We cloned the MbWRKY33 gene from Malus baccata for this research, and its roles in salt stress tolerance were analyzed. Phylogenetic tree analysis revealed that MbWRKY33 and PbWRKY33 have the highest homology. Subcellular localization revealed that MbWRKY33 was located within the nucleus. An analysis of tissue-specific expression showed that MbWRKY33 had relatively high expression levels in young leaves and roots. Moreover, Arabidopsis thaliana plants overexpressing MbWRKY33 exhibited stronger resistance to salt stress compared with the wild type (WT) and the unloaded line empty vector (UL). Under the treatment of 200 mM NaCl, transgenic Arabidopsis thaliana plants exhibited significantly higher activities of antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) than the control. In contrast, the WT and the UL lines had elevated levels of malondialdehyde (MDA) and reactive oxygen species (ROS). In addition, MbWRKY33 elevates transgenic plant resistance to salt stress by regulating the expression levels of AtNHX1, AtSOS1, AtSOS3, AtNCED3, AtSnRK2, and AtRD29a. Results indicated that MbWRKY33 in Malus might be linked to high-salinity stress responses, laying a foundation for understanding WRKY TFs’ reaction to such stress. Full article

The release of metformin into the environment poses significant challenges, yet its effects on higher plants remain largely unexplored. In this study, we investigated the impact of metformin exposure on duckweed (Lemna turionifera 5511) across varying concentrations ranging from 0 to 0.16 mg/mL. Our findings revealed that leaves exhibited chlorosis, accompanied by a reduction in biomass, particularly evident at concentrations of 0.1, 0.13, and 0.16 mg/mL of metformin. Chlorophyll fluorescence analysis showed that MF exposure reduced photosynthetic performance, indicated by decreased Fv/Fm and Y (II), and increased Y (ND) and NPQ, suggesting impaired photosystem efficiency and altered energy dissipation. Additionally, genes involved in photosynthesis exhibited significantly reduced transcript abundance. Moreover, metformin was found to alter the transcript levels of GH3 and SAUR genes, which are associated with auxin signaling, and increase the expression of SnRK2, a key component of the abscisic acid signaling pathway. These findings shed light on the toxicological effects of metformin on higher plants, providing valuable evidence regarding the toxicity of this pharmaceutical contaminant. Subsequently, we investigated the absorption of metformin by duckweed (0.128 mg/g FW in 7 days) at a concentration of 0.13 mg/mL, observing a gradual decrease in metformin concentration to zero over a period of 10 days. Notably, the optimal adsorption time was determined to be ten days. Hence, duckweed emerges as a promising candidate for the concurrent bioremediation of metformin-contaminated water and the production of high-quality biomass. Full article

Autophagy, an evolutionarily conserved process for cellular component degradation and recycling, occurs in yeasts, animals, and plants under both stress and normal conditions. However, the functions of autophagy-related genes (ATGs) in watermelon (Citrullus lanatus) remain uncharacterized. In this study, a phylogenetic analysis identified 27 ATGs belonging to 16 subfamilies in the watermelon genome. A promoter analysis revealed that all the ClaATGs contain multiple photo-responsive elements. Tissue-specific expression profiling showed diverse expression patterns of ClaATGs across different tissues, except for the constitutively expressed ClaATG6. Exogenous independent treatments with glucose, naphthalene acetic acid, and 6-benzylaminopurine induced the expression of most ClaATGs, particularly members of the ClaATG8 subfamily, in the graft unions of normal and etiolated seedlings. A sugar application significantly increased autophagosome numbers during the early stages of graft interface healing, accompanied by the upregulation of ClaATG6, ClaATG8b, ClaATG8i, and ClaTOR, as well as the downregulation of ClaSnRK1. These findings elucidate the roles of ATGs in watermelon graft union formation and provide novel insights into the complex functions of autophagy in plant development and stress responses. Full article

Salinity stress poses a major challenge to agricultural productivity worldwide, including for pumpkin, a globally cultivated vegetable crop with great economic value. To deal with salt stress, plants exhibit an array of responses such as changes in their root system architecture. However, the root phenotype and gene expression of pumpkin in response to different concentrations of NaCl remains unclear. To this end, this study evaluated the effects of salinity stress on root architecture in C. moschata (Cmo-1, Cmo-2 and Cmo-3) and C. maxima (Cma-1, Cma-2 and Cma-3), as well as their hybrids of C. moschata and C. maxima (Ch-1, Ch-2 and Ch-3) at the germination and seedling stages. The results showed that the total root length and the number of root tips decreased by more than 10% and 5%, respectively, under 180 mM NaCl conditions compared to those under the 0 mM NaCl conditions. In contrast, the total root length and the number of root tips were increased or decreased under 60 mM NaCl conditions. Meanwhile, salt stress was considered severe when treated with more than 120 mM NaCl, which could be used to evaluate the salt tolerance of the germplasm resources of pumpkin. In addition, the transcriptional changes in the roots of both Cmo-3 and Cma-2 under salt stress were analyzed via RNA-sequencing. We found 4299 and 2141 differential expression genes (DEGs) in Cmo-3 and Cma-2, respectively. Plant hormone signal transduction, Phenylpropanoid biosynthesis and the MAPK signaling pathway were found to be the significant KEGG pathways. The expression of ARF (auxin response factor), B-ARR (type-B response regulator) and PYR (pyrabactin resistance)/PYL (PYR-LIKE) genes was downregulated by NaCl treatment. In contrast, the expression of SnRK2 (sucrose non-fermenting-1-related protein kinase 2) and AHP (histidine-containing phosphotransmitter) genes was downregulated in Cmo-3 and upregulated in Cma-2. These findings will help us better understand the mechanisms of salt tolerance in pumpkins and potentially provide insight into enhancing salt tolerance in crop plants. Full article

Background: Protein Phosphatase 2C (PP2C), a conserved family in plants, plays a crucial role in ABA and MAPK signaling pathways. Its functional diversity provides key mechanisms for plants’ adaptation to environmental changes. However, research on PP2C family members remains significantly underexplored in seagrasses, which are model organisms adapted to complex marine environments. Methods: In this study, we systematically analyzed the PP2C gene family in eelgrass using bioinformatic methods and performed a qPCR experiment to verify the expression of a few members in their response to salt stress. Results: The eelgrass PP2C gene family comprises 52 members, categorized into 13 subfamilies. Most PP2C genes exhibit a differential expression across various organs, with some members showing significant organ specificity. For instance, 12 members are specifically highly expressed in male flowers, suggesting that PP2Cs may function in male flower development. Additionally, four members (ZosmaPP2C-04, ZosmaPP2C-07, ZosmaPP2C-15, and ZosmaPP2C-18) in eelgrass are up-regulated under salt stress, with a qPCR confirming their response. The syntenic genes of ZosmaPP2C-15 and ZosmaPP2C-18 were identified across multiple species, indicating their evolutionary conservation. Numerous response elements associated with plant hormones and stress were identified within the promoter sequences of eelgrass PP2C genes. Notably, the promoter regions of salt-responsive genes are rich in the ABRE, implying that ABA may participate in regulating the expression of these PP2Cs. Furthermore, the predictive analysis of protein interactions suggests the potential existence of the ABA core signaling module PYL-PP2C-SnRK2 in eelgrass. Conclusions: This study provides a new insight for understanding the biological functions of the PP2C family in eelgrass, which is important for elucidating the mechanisms of its growth, development, and environmental adaptability. Full article

This article methodically reveals how, in woody plants (poplar), the interaction between N and P coordinates root structure and nutrient absorption through a complex hormone signaling network. This study bridges a significant gap in our knowledge of nutrient interaction networks. The results demonstrate that NO₃⁻ significantly enhances the gene expression and enzymatic activity of organic acid synthases (MDH, PEPC) and APs. Furthermore, it synergizes with IAA/ABA signals to refine root structure, enhancing the surface area for P absorption. In low Pi availability environments, NO₃⁻ further promotes P recycling by simultaneously boosting the levels of Pi transport proteins (notably, the PHO family), facilitating myo-inositol phosphate metabolism (via IMP3/ITPK1-mediated PP-InsPs degradation), and augmenting IAA/SA signals. Pi induces the activity of N assimilation enzymes (GS/GOGAT/GDH), facilitating nitrogen metabolism. However, in the absence of N, it leads to a metabolic imbalance characterized by high enzymatic activity but low efficiency. Alternatively, adequate N availability allows Pi to improve root robustness and N assimilation efficiency, mediated by IAA/GA accumulation and ABA signaling (e.g., SNRK2/ABF). We propose the existence of an intricate network in poplar, orchestrated by transcriptional cascades, metabolic regulation, and hormonal synergism. Key modules such as SPX-PHR, NLA, HHO2, and MYB59 are likely central to this network’s function. These findings offer a foundational framework for the development of molecular breeding and precise fertilization strategies, enhancing the efficient use of N and P in forestry. Full article