Search Results (337)

(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

Polysaccharides derived from green algae have garnered significant attention owing to their distinctive structural characteristics and biological activities. In particular, sulfated polysaccharides from these algae represent a promising frontier in the discovery of novel therapeutic agents. In this present study, a sulfated galactan from Caulerpa taxifolia, designated SGC, was obtained by dilute alkali extraction and chromatographic purification. On the basis of chemical and spectroscopic analyses, the backbone of SGC was constituted by a backbone of →3)-β-d-Galp-(1→ with sulfate substitution at the C-2 and a branch on C-6. The side chains contained →6)-β-d-Galp(2SO₄)-(1→, →6)-β-d-Galp(3OMe)-(1→ and →3)-β-d-Galp(4,6-Pyr)-(1→ units. SGC possessed strong hypoglycemic activity in vitro, as evaluated by an assay of α-amylase inhibition. The anti-diabetic activity of SGC in vivo was further investigated using T2DM mice induced by high-fat diet combined with streptozotocin. The results indicated that SGC markedly restored body weight, reduced fasting blood glucose and possessed a significant glucose-regulating effect. Furthermore, SGC effectively increased insulin sensitivity and mitigated insulin resistance. Additionally, SGC effectively regulated lipid metabolism and alleviated oxidative stress. Notably, SGC ameliorated liver and pancreas damage induced by high-fat diet combined with streptozotocin. The investigation demonstrates that SGC is a unique sulfated galactan and has potential as a novel anti-diabetic agent. 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

PYR/PYL (pyrroloquinoline quinone resistance/PYR1-like) are receptors for abscisic acid (ABA) in plants and play a crucial role in responses to abiotic stress. In this study, we identified 63 members of the StPYL gene family at the tetraploid whole-genome level in potatoes. We analyzed the physicochemical properties of these 63 StPYLs and constructed a phylogenetic tree using Arabidopsis thaliana and potato (Solanum tuberosum L.) cultivar ‘DM’ as the reference. By examining gene structure, conserved protein motifs, and collinearity, we found that StPYLs are highly conserved throughout evolution. The gene expression heat map under salt stress revealed that 57 StPYL genes are involved in the salt stress response. Among them, the expression level of StPYL9a-like changed significantly under salt stress. Through genetic transformation, we observed that overexpression of StPYL9a-like enhanced the growth and survival of potato plants under salt stress compared to the wild type. The contents of proline (Pro), superoxide dismutase (SOD), and chlorophyll in the leaves of overexpressing plants increased, while malondialdehyde (MDA) levels decreased. This suggests that StPYL9a-like positively regulates salt tolerance by affecting antioxidant enzyme activity and osmotic adjustment substances in potatoes. Subcellular localization demonstrated that StPYL9a-like is localized in the nucleus. This study provides a reference for the functional research of PYLs in potatoes, offers a basis for screening potato genes related to salt stress, and lays a foundation for developing salt-tolerant potato varieties. Full article

Global climate change is pushing insects into colder regions. Understanding their cold tolerance is important for predicting population dynamics. During overwintering, Streltzoviella insularis larvae activate the AMPK signaling pathway. This suggests that energy metabolism plays a key role under cold stress. In this study, we used enzyme activity assays, LC-MS-based targeted metabolomics, and transcriptome sequencing. We focused on six key enzymes in glycolysis and the TCA cycle. We also measured related metabolites and regulatory genes. Hexokinase (HK) and citrate synthase (CS) activities were highly sensitive to temperature. HK increased then markedly decreased; CS was significantly downregulated. Pyruvate kinase (PK), isocitrate dehydrogenase (IDH), and α-ketoglutarate dehydrogenase (KGD) showed trends that matched changes in larval cold tolerance, exhibiting an up–down–up expression trend. Glycolytic metabolites (glucose-6-phosphate, fructose-6-phosphate, 1,6-fructose-diphosphate, phosphoenolpyruvic acid) peaked at −10 °C. TCA intermediates (citrate, acetyl-CoA, α-ketoglutaric acid, and isocitrate) were more abundant at 0–4 °C. Pyruvate increased significantly. PYR content showed a significant increase followed by a decrease, peaking at 0 °C. It was converted into lactate and acetyl-CoA. ATP levels dropped and then increased, reaching their lowest level at 0 °C. These results suggest a shift from aerobic to mixed aerobic–anaerobic metabolism. Transcriptome data showed differential expression of key metabolic genes such as phosphoenolpyruvate carboxykinase, phosphoglycerate kinase, and ATP synthase subunit beta. These gene changes supported the trends in enzymes and metabolites. Our findings reveal a coordinated metabolic and transcriptional response to cold. This provides a basis for understanding the cold adaptation and potential range expansion of S. insularis. Full article

Abscisic acid (ABA) is a key phytohormone involved in regulating plant growth and responses to environmental stress. As receptors of ABA, pyrabactin resistance 1 (PYR)/PYR1-like (PYL) proteins play a central role in initiating ABA signal transduction. In this study, a total of 30 PopPYL genes were identified and classified into three sub-families (PYL I–III) in the pan-genome of 17 Populus species, through phylogenetic analysis. Among these subfamilies, the PYL I subfamily was the largest, comprising 21 members, whereas PYL III was the smallest, with only four members. To elucidate the evolutionary dynamics of these genes, we conducted synteny and Ka/Ks analyses. Results indicated that most PopPYL genes had undergone purifying selection (Ka/Ks < 1), while a few were subject to positive selection (Ka/Ks > 1). Promoter analysis revealed 258 cis-regulatory elements in the PYL genes of Populus euphratica (EUP) and Populus pruinosa (PRU), including 127 elements responsive to abiotic stress and 33 ABA-related elements. Furthermore, six structural variations (SVs) were detected in PYL_EUP genes and significantly influenced gene expression levels (p < 0.05). To further explore the functional roles of PYL genes, we analyzed tissue-specific expression profiles of 17 PYL_EUP genes under drought stress conditions. PYL6_EUP was predominantly expressed in roots, PYL17_EUP exhibited leaf-specific expression, and PYL1_EUP showed elevated expression in stems. These findings suggest that the drought response of PYL_EUP genes is tissue-specific. Overall, this study highlights the utility of pan-genomics in elucidating gene family evolution and suggests that PYL_EUP genes contribute to the regulation of drought stress responses in EUP, offering valuable genetic resources for functional characterization of PYL genes. Full article

Fruit shape is an important quality and yield trait of pear, and the fruit shape of ‘Laiyang Cili’ presents a spindle shape which seriously affects its commercial value. Calyx excision treatment could change the fruit shape, while the underlying genes and their regulatory mechanism remain poorly understood. In this study, we constructed RNA-seq libraries of pear treated with calyx excision to explore underlying regulatory mechanisms. At the early stage of the calyx excision treatment, the numbers of differentially expressed genes (DEGs) between each comparison group were relatively high and gradually decreased along with fruit development. The expression pattern of the DEGs ranked in the top 30 of the six groups had obvious divergence, and DEGs were mainly distributed in the “after calyx excision treatment (0 days)” (AC0d) and AC2d groups. The DEGs were mainly enriched in plant hormone signal transduction and plant defense response. We identified 17 candidate genes related to fruit shape and tested their expression patterns along with fruit development. Among them, nine candidate genes expression trends were consistent with fragments per kilobase of exon model per million mapped fragment (FPKM) values, including MYB62, outer envelope pore protein 62 (OEP62), auxin response factor 3 (ARF3), auxin-responsive protein 50 (SAUR50), protein phosphatase 2C 51 (PP2C 51), major allergen Pyr c 1 (PYRC1), aquaporin TIP1-3 (TIP1-3), transcription factor TGA4 (TGA4) and auxin-responsive protein 17 (IAA17). And then, weighted gene co-expression network analysis (WGCNA) analysis revealed that the OVATE family protein (OFP) and SUN domain-containing protein (SUN) were divided into the MEblue model, which had a positive correlation with calyx excision treatment, and the expression trend of LOC103960706 (OFP8) appeared cohesive with FPKM values. Pbr014104.1 and Pbr016952.1, which were the ortholog genes of LOC103960706, were further identified from the pear genome, and were found to be highly expressed in pear fruit through RT-PCR analysis. Taken together, the key stage determining the development of fruit shape was in the early stage after calyx excision treatment, and fruit shape regulation and development were co-regulated by multiple genes. Full article

Blue mold of pome fruit, caused by Penicillium expansum, is controlled through postharvest applications of thiabendazole (TBZ), pyrimethanil (PYR), and fludioxonil (FDL). However, multi-fungicide-resistant isolates have emerged in the U.S. Pacific Northwest and their impact on decay control in long-term storage is unknown. This study evaluated the fitness of P. expansum isolates sensitive to all three postharvest fungicides (wild-types) and those resistant to TBZ (single-resistant), TBZ and PYR, or PYR and FDL (dual-resistant), and triple-resistant to the three fungicides. On nutrient-poor media, resistant isolates showed reduced conidial germination, whereas no significant differences were observed in germination, mycelial growth, or sporulation between phenotypes on nutrient-rich media at 1.5 and 20 °C. Regardless of their sensitivity phenotype, FDL-resistant isolates showed increased sensitivity to osmotic and oxidative stresses. Pathogenicity and virulence were not affected by the sensitivity phenotype on apples after six months of storage at 1.5 °C. Analysis of cumulative fitness changes indicated fitness loss under low-temperature in vitro and increased fitness under fungicide selection pressure on fruit in most resistant phenotypes. Gene expression analysis showed differential regulation of fitness-related genes, with most being up-regulated by TBZ. Overall, the results suggest that resistance in P. expansum may carry context-dependent fitness penalties, especially under high-stress conditions. Full article

Background: During infection with the cytomegalovirus (CMV), the membrane system of the infected cell is remodelled into a megastructure called the assembly compartment (AC). These extensive changes may involve the manipulation of the host cell proteome by targeting a pleiotropic function of the cell such as ubiquitination (Ub). In this study, we investigate whether the Ub system is required for the establishment and maintenance of the AC in murine CMV (MCMV)-infected cells Methods: NIH3T3 cells were infected with wild-type and recombinant MCMVs and the Ub system was inhibited with PYR-41. The expression of viral and host cell proteins was analyzed by Western blot. AC formation was monitored by immunofluorescence with confocal imaging and long-term live imaging as the dislocation of the Golgi and expansion of Rab10-positive tubular membranes (Rab10 TMs). A cell line with inducible expression of hemagglutinin (HA)-Ub was constructed to monitor ubiquitination. siRNA was used to deplete host cell factors. Infectious virion production was monitored using the plaque assay. Results: The Ub system is required for the establishment of the infection, progression of the replication cycle, viral gene expression and production of infectious virions. The Ub system also regulates the establishment and maintenance of the AC, including the expansion of Rab10 TMs. Increased ubiquitination of WASHC1, which is recruited to the machinery that drives the growth of Rab10 TMs, is consistent with Ub-dependent rheostatic control of membrane tubulation and the continued expansion of Rab10 TMs. Conclusions: The Ub system is intensively utilized at all stages of the MCMV replication cycle, including the reorganization of the membrane system into the AC. Disruption of rheostatic control of the membrane tubulation by ubiquitination and expansion of Rab10 TREs within the AC may contribute to the development of a sufficient amount of tubular membranes for virion envelopment. Full article

This study aimed to investigate the effect of wildfire episodes on air quality in terms of particulate matter (PM) and carbonaceous compound concentration in ambient air, and to assess deviations from typical annual patterns. The sampling was performed at a rural background site near the Adriatic coast in Croatia through 2024. To better understand contributions caused by fire events, the levels of organic carbon (OC), elemental carbon (EC), black carbon (BC), pyrolytic carbon (PyrC), optical carbon (OptC), water-soluble organic carbon (WSOC), levoglucosan (LG), mannosan (MNS), and galactosan (GA) were determined in PM₁₀ and PM_2.5 fractions (particles smaller than 10 µm and 2.5 µm, respectively). The annual mean concentrations of PM₁₀ and PM_2.5 were 14 µg/m³ and 8 µg/m³, respectively. During the fire episode, the PM_2.5 mass contribution to the total PM₁₀ mass exceeded 65%. Total carbon (TC) and OC increased by a factor of 7, EC and BC by 12, PyrC by 8, and WSOC by 12. The concentration of LG reached 1.219 μg/m³ in the PM₁₀ fractions and 0.954 μg/m³ in the PM_2.5 fractions, representing a 200-fold increase during the fire episode. Meteorological data were integrated to assess atmospheric conditions during the fire episode, and the specific ratios between fire-related compounds were analyzed. Full article

Humulus lupulus L. (hop) is a multipurpose crop valued for its essential role in beer production and for its bioactive compounds with recognized medicinal properties. Otherwise, climate change represents a major challenge to agriculture, particularly impacting the cultivation of crops with stenoecious characteristics, such as hop. This highlights the urgent need to enhance crop resilience to adverse environmental conditions. The phytohormone abscisic acid (ABA) is a key regulator of plant responses to abiotic stress, yet the ABA signaling pathway remains poorly characterized in hop. Harnessing the publicly available hop genomics resources, we identified eight members of the PYRABACTIN RESISTANCE 1 LIKE ABA receptor family (HlPYLs). Phylogenetic and gene structure analyses classified these HlPYLs into the three canonical ABA receptor subfamilies. Furthermore, all eight HlPYLs are likely functional, as suggested by the protein sequence visual analysis. Expression profiling indicates that ABA perception in hop is primarily mediated by the HlPYL1-like and HlPYL8-like subfamilies, while the HlPYL4-like group appears to play a more limited role. Structure modeling and topology predictions of HlPYL1b and HlPYL2 provided insights into their potential functional mechanisms. To assess the physiological relevance of ABA signaling in hop, we evaluated the impact of exogenous ABA application during the ex vitro acclimatization phase. ABA-treated plants exhibited more robust growth, reduced stress symptoms, and improved acclimatization success. These effects were associated with reduced leaf transpiration and enhanced stomatal closure, consistent with ABA-mediated drought tolerance mechanisms. Altogether, this study provides the first comprehensive characterization of ABA receptor components in hop and demonstrates the practical utility of ABA in improving plant performance under ex vitro conditions. These findings lay the groundwork for further functional studies and highlight ABA signaling as a promising target for enhancing stress resilience in hop, with broader implications for sustainable agriculture in the face of climate change. Full article

The reduction of Cu(NO₃)₂ by HS^tBu in CH₃CN under Ar atmosphere produces a light-yellow solution containing numerous {Cu_x(S^tBu)_y} species. The addition of different pyridines (py-R) into this solution results in the formation of {Cu₆(S^tBu)₄} hexanuclear complexes. The slow Et₂O diffusion leads to crystals of [Cu₆(S^tBu)₄(2-Me-py)₅(CH₃CN)(NO₃)](NO₃) (1), [Cu₆(S^tBu)₄(Me₃py)₄(NO₃)₂]·3.5CH₃CN (2a), [Cu₆(S^tBu)₄(Me₃py)₅(NO₃)](NO₃)·5CH₃CN (2b), (NHEt₃)[Cu₆(S^tBu)₄(CH₃CN)₃(NO₃)₃]·H₂O (3), [Cu₆(S^tBu)₄(2-Br-py)₄(NO₃)₂]·2-Br-Py (4), [Cu₆(S^tBu)₄(3-Br-py)₆][Cu₆(S^tBu)₄(CH₃CN)₆](NO₃)₄·9CH₃CN (5), and [Cu₆(S^tBu)₄(3-Cl-py)₆][Cu₆(S^tBu)₄(CH₃CN)₆](NO₃)₄·5CH₃CN (6). The titled compounds were characterized by single crystal X-ray diffraction (SCXRD). The Cu···Cu contacts were analyzed with quantum chemical methods. Full article

Rice production faces new challenges from emerging diseases due to intensive cultivation practices and climate warming in China. A new rice leaf bacterial disease has recently occurred in Northeast China. The symptoms of the disease are similar to those of bacterial leaf blight. Disease lesions spread along leaf edges and are later dried up due to water loss. In this study, 17 bacterial isolates were identified as the causal agents of the new disease following Koch’s postulates. These strains are categorized into two groups based on colony morphology and molecular characterization. Phylogenetic analysis using the five housekeeping genes leuS, gyrB, fusA, pyrG, and rplB reveals that the two groups of the isolates belong to Pantoea ananatis and P. eucalypti, respectively. The new rice disease is caused by P. ananatis, P. eucalypti, or a combination of both bacterial species. A complete genome map has also been assembled for P. eucalypti. Meanwhile, some important virulence factors have been predicted based on gene annotation and determination of extracellular enzymes. Collectively, this study represents the first report of a new rice leaf disease caused by P. eucalypti and the first high-quality genome assembly of P. eucalypti that infects rice leaves. Full article

To investigate how dysregulated transient receptor potential canonical channels (TRPCs) are associated with Alzheimer’s disease (AD), we challenged primary neurons with amyloid-β (Aβ). Both the naturally secreted or synthetic Aβ oligomers (AβOs) induced long-lasting increased TRPC3 and downregulated the TRPC6 expression in mature excitatory neurons (CaMKIIα-high) via a Ca²⁺-dependent calcineurin-coupled NFAT transcriptionally and calpain-mediated protein degradation, respectively. The TRPC3 expression was also found to be upregulated in pyramidal neurons of human AD brains. The selective downregulation of the Trpc6 gene induced synaptotoxicity, while no significant effect was observed from the Trpc3-targeting siRNA, suggesting potentially differential roles of TRPC3 and 6 in modulating the synaptic morphology and functions. Electrophysiological recordings of mouse hippocampal slices overexpressing TRPC3 revealed increased neuronal hyperactivity upon the TRPC3 channel activation by its agonist. Furthermore, the AβO-mediated synaptotoxicity appeared to be positively correlated with the degrees of the induced dendritic Ca²⁺ flux in neurons, which was completely prevented by the co-treatment with two pyrazole-based TRPC3-selective antagonists Pyr3 or Pyr10. Taken together, our findings suggest that the aberrantly upregulated TRPC3 is another ion channel critically contributing to the process of AβO-induced Ca²⁺ overload, neuronal hyperexcitation, and synaptotoxicity, thus representing a potential therapeutic target of AD. Full article

Environmental concerns about the widespread use of non-biodegradable plastic have generated interest in developing quick and effective methods to degrade synthetic polymers. With millions of tons of plastic waste generated annually, biodegradation by microorganisms presents a promising and eco-friendly solution. However, a bottleneck has arisen due to the lack of standardized methods for verification of the biodegradation process. Based on this literature review, he techniques most commonly employed for this purpose currently include measuring mass loss, examining the surface of plastic fragments by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and using analytical methods such as Fourier transform infrared spectroscopy (FTIR), pyrolysis–gas chromatography–mass spectrometry (Pyr-GC/MS) or high-performance liquid chromatography (HPLC). Each of these methods has its advantages and disadvantages. Nevertheless, currently, there is no universal approach to accurately assess the ability of individual microorganisms to degrade plastics. In this review, we summarize the latest advances in techniques for detecting biodegradation of synthetic polymers and future directions in the development of sustainable strategies for mitigating plastic pollution. Full article