Search Results (35)

The dormancy of lilies is an important physiological process involving vernalisation and the differentiation and maturation of flower buds. We have cloned an aquaporin, SbP1P1;2, from the Lilium ‘Siberia’. Subcellular localisation analysis indicates that it is a protein that is localised to the plasma membrane in Nicotiana benthamiana. VIGS-mediated transient silencing revealed that silencing the SbPIP1;2 gene inhibited the development of lily flower buds, while those in the control group differentiated earlier to the anther primordia stage. Notably, the ABA levels in the control group had dropped significantly by day 63, suggesting that dormancy ended earlier than in the treatment group. The test plants’ phenotype is characterised primarily by the fact that silencing the SbPIP1;2 gene inhibits both flower bud development and root growth. The dormancy-to-sleep transition phase (PS vs. TS) was also the period during which the largest number of differentially expressed genes was observed. KEGG enrichment analysis indicates that starch and sucrose metabolic pathways are most active from the onset to the completion of dormancy release and that significant differences occur in several key genes within these pathways. These include alpha-trehalose-phosphate synthase (TPS), sucrose phosphate synthase (SPS), trehalase (TREH), fructokinase-1 (E2.7.1.1), beta-glucosidase (bglB), glycogen synthase (glgA), glucose-6-phosphate isomerase (GPI), and ectonucleotide pyrophosphatase/phosphodiesterase family members 1 and 3 (ENPP1/3). The discovery that aquaporins promote dormancy breaking in lilies is a highly successful case study for aquaporin research in flowers. Full article

Lithocarpus litseifolius is a medicinal tea plant recognized for its sweet flavor and anti-diabetic properties, but its limited leaf yield under cultivation restricts its economic sustainability. Melatonin (MLT) is a multifunctional plant growth regulator, but its roles in leaf growth under normal conditions remain not fully understood. Herein, we investigated the effects and mechanisms of foliar-applied MLT on L. litseifolius seedlings, including growth indices, phytohormone profiles, photosynthetic characteristics, and transcriptome alterations. The 100 μM MLT treatment significantly enhanced leaf dry weight by 33.8% and leaf dry matter content by 22.2% compared to the control group. MLT decreased both free and bound abscisic acid (ABA), while increasing gibberellins (GAs), 5-deoxystrigol, auxins (e.g., IAM), and cytokinins (e.g., cZ9G). Additionally, exogenous MLT improved photosynthetic rate, stomatal conductance, chlorophyll content, and soluble sugars in leaves. RNA-seq revealed that MLT up-regulated DEGs involved in hormone biosynthesis and signaling (CYP707A, BAK1, D14, CCD1, and IAA6), photosynthesis (PsbC/B, PetH, PsaB, and ATPase β), and sugar metabolism (WAXY, glgC, and otsB). Our results demonstrate that MLT promotes leaf dry matter accumulation through coordinated phytohormone homeostasis, photosynthetic enhancement, and transcriptional regulation, offering a cost-effective strategy to improve leaf yield in L. litseifolius. Full article

The cyanobacterial circadian clock orchestrates a wide range of physiological processes. However, its involvement in extracellular vesicle (EV) biogenesis remains largely unexplored. In this study, we investigated the role of the master circadian output regulator RpaA in modulating EV production in Synechococcus elongatus PCC 7942. Deletion of rpaA simultaneously abolished the bioluminescence rhythmicity and rhythmic EV production, whereas overexpression of rpaA enhances the output of circadian clock signals in a dose-dependent manner and markedly increases the bioluminescence intensity and EV production while maintaining the normal circadian oscillation patterns. Transcriptional analyses indicated that rpaA positively regulates lpxD to promote membrane synthesis and differentially inhibits glgC transcription to optimize carbon allocation. These findings reveal a previously unrecognized link between circadian output signaling and EV biogenesis and suggest that rpaA overexpression is an effective strategy for improving the yield of EVs. It also provides novel insights and regulatory targets for facilitating the synthesis of other high-value metabolites in cyanobacterial cell factories, and holds certain practical significance for advancing cyanobacterial synthetic biology research and the application of nanocarrier technology. Full article

Nonsteroidal anti-inflammatory drugs (NSAIDs) can exacerbate urticaria and/or angioedema in up to 30% of patients with chronic urticaria (CU), representing a distinct subtype characterized by heightened inflammation and leukotriene-driven pathophysiology. MicroRNAs (miRNAs) are post-transcriptional regulators that modulate immune and inflammatory responses. This study aimed to identify differentially expressed miRNAs (DEMs) according to NSAID hypersensitivity status and to elucidate their molecular networks in CU. Serum miRNA profiles were analyzed in 14 NSAID-exacerbated CU (NECU) and 16 NSAID-tolerant CU (NTCU) patients using an Affymetrix GeneChip^® miRNA 4.0 Array. DEMs were identified (fold difference > 1.5, p < 0.05), and validated targets were retrieved from the multiMiR database for network construction and Gene Ontology enrichment analyses. NECU patients exhibited a higher frequency of angioedema and systemic corticosteroid use than NTCU patients. Eight DEMs were identified, including upregulated miR-5001-5p, miR-4270, and miR-6869-5p, and downregulated miR-6511b-5p, miR-2277-5p, and miR-378h in NECU. Network integration revealed AGO2-BTG2-LMNB2, NFIC-ZZZ3, and NUFIP2-GLG1 as central clusters, implicating dysregulation of mRNA decay and inflammatory signaling pathways. Reduced miR-6511b-5p expression may derepress BRG1, enhancing chromatin accessibility for inflammatory and leukotriene-synthetic genes. Distinct miRNA signatures differentiate NECU from NTCU, implying a miR-5001-5p/miR-6511b-5p–mRNA decay axis that links impaired post-transcriptional regulation with leukotriene-driven inflammation in CU. These findings highlight candidate miRNAs as potential biomarkers for disease endotyping and therapeutic stratification. Full article

Cold resistance is an important characteristic of sustainable development in the grape industry. The intraspecific recurrent selection in the Vitis vinifera (V. vinifera) method uses high-quality varieties as breeding materials and the substitution and accumulation of minor resistance genes, breeding high-quality grapes with cold resistance. This study was conducted to identify and genetically analyse the cold resistance of a V. vinifera hybrid population (Ecolly × Dunkelfelder), screen for highly resistant and sensitive plant samples, and use high-throughput sequencing to perform transcriptome sequencing and related differential gene expression analysis on each sample. The results revealed that the cold resistance of the hybrid offspring population was characterised by continuous quantitative trait inheritance, with 38 differentially expressed genes (7 upregulated genes and 31 downregulated genes) between the high resistance and high-sensitivity types. Analysis of genes related to various pathways, related to cold resistance, revealed that CYP76F10, Dxs, GERD, NMT, GDE1, glgC, and DHQ-SDH, as well as transcription factor MYB, HB, and MADS family genes, are key candidate genes for V. vinifera cold resistance research. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to investigate the expression characteristics of the six genes that were differentially expressed genes, the results of which were essentially consistent with the results of RNA-seq. Specifically, NMT may enhance cold resistance by enhancing membrane lipid stability. The synergistic expression pattern of CYP76F14 and Dxs suggests its key role in terpene synthesis. By exploring potential genes related to micro effects, a theoretical foundation for further exploration of new high-quality cold-resistant grape varieties has been provided. Full article

Background/Objectives: Houttuynia cordata Thunb., a widely consumed vegetable and traditional food in Asia, possesses significant nutritional value. However, the impact of geographical origin on its nutritional metabolite composition, crucial for food quality and functionality, remains unclear. Methods: Here, we conducted a comprehensive metabolomic analysis of H. cordata cultivated across six major Chinese regions (Yunnan, Guangxi, Guizhou, Sichuan, Chongqing, Hubei) using UPLC-MS/MS. Results and Conclusions: We identified 496 nutritional metabolites, predominantly amino acids and derivatives (53.23%). Key bioactive carbohydrates, maltotriose and maltitol, exhibited distinct geographical accumulation patterns: maltotriose was significantly enriched in Yunnan (YN), while maltitol accumulated predominantly in Sichuan (SC). Integrated transcriptomic analysis linked this variation to the differential expression of starch metabolism genes (GBE1/glgB, α-amylases, β-amylases). Bioinformatic evaluation suggested potential health-related functionalities associated with these metabolites. These findings provide critical insights into the geographical determinants of H. cordata nutritional quality and functional properties. They offer a scientific foundation for optimizing cultivation practices based on regional advantages and developing H. cordata as a region-specific, high-value vegetable and functional food ingredient targeting distinct nutraceutical applications. Full article

The present research investigates the fine-scale spatial genetic structure (SGS) and gene flow dynamics in the endangered relict tree Tetracentron sinense, a keystone species in China’s montane ecosystems facing severe habitat fragmentation and genetic erosion. Utilizing genome-wide SNPs from 378 individuals across four natural populations (BMXS, MGFD, GLGS, SXFP), derived from ddRAD-seq, we quantified genetic diversity, SGS (Sp statistic), and dispersal patterns through spatial autocorrelation, parentage analysis, and age-class stratification. Results indicated critically low heterozygosity (observed heterozygosity, H_O = 0.019–0.022) and high inbreeding coefficient (Fis = 0.147–0.304), with moderate SGS (Sp = 0.0076–0.021) suggesting restricted gene flow (effective dispersal radius: 11–32 m). Seed-mediated dispersal was predominant, but topography and rainfall constrained dispersal (<5% beyond 50 m). Saplings exhibited stronger SGS, and the SXFP population experienced 100% sapling mortality due to inbreeding depression. Conservation efforts should prioritize assisted gene flow, habitat restoration, and ex situ sampling at distances greater than 115 m to preserve genetic diversity and adaptive potential. This study highlights the urgent need for genomics-informed conservation strategies in fragmented montane ecosystems. Full article

This study highlights a new avenue to improve polyhydroxybutyrate (PHB) productivity by optimizing genes related to arginine catabolism, which influences nitrogen metabolism in cyanobacteria based on the carbon/nitrogen metabolism balance. In the Synechocystis sp. PCC 6803 wild type (WT) and its adc1 mutant (Δadc1), the native putA gene, responsible for the oxidation of proline to glutamate, was overexpressed to create the OXPutA and OXPutA/Δadc1 strains, respectively. PHB accumulation was considerably higher in OXPutA and OXPutA/Δadc1 under the nitrogen-deprived condition than in strains that overexpressed the proC gene, involved in proline synthesis. The increased transcript level of glgX, associated with glycogen degradation, confirmed that glycogen served as the primary carbon source for PHB synthesis under nitrogen stress without any carbon source addition. Furthermore, proline and glutamate level changes helped cells deal with nitrogen stress and considerably improve intracellular carbon/nitrogen metabolism. As indicated by elevated levels of proA and argD transcripts as well as chlorophyll a accumulation, this impact was most noticeable in strains that overexpressed putA, which was crucial for the synthesis of glutamate, a precursor for important metabolic pathways that respond to nitrogen stress. Therefore, our metabolic model presents PHB-producing strains as promising candidates for biomaterial biotechnology applications in medical and agricultural fields. Full article

The red panda (Ailurus), a rare and endangered mammal native to the Himalayan–Hengduan Mountains, has a specialized bamboo diet. Combining morphological and genomic evidence, red pandas have been classified as Ailurus fulgens and Ailurus styani. However, previous studies focused on ecological aspects such as foraging behaviors, habitat use and threats within specific distributions; hence, there is still a gap in quantitative comparative studies on the trophic niches of these two species. In this study, we calculated and compared the isotopic trophic niche widths of A. styani and A. fulgens by measuring carbon and nitrogen stable isotopes in hair keratin of 102 red pandas, then conducting a fecal analysis to explore the diet of a population. The results showed that (1) there was no significant difference in δ¹³C values between A. styani (−24.73 ± 1.26‰, N = 86) and A. fulgens (−24.43 ± 1.20‰, N = 16); however, A. styani had 1.4‰ higher average δ¹⁵N value than that of A. fulgens, and the isotopic niche widths converted by Bayesian ellipse model were A. styani SEA_C = 4.40‰², A. fulgens SEA_C = 4.70‰², which might be caused by their lower and narrower altitude distribution. (2) Niche widths of three genetic populations in A. styani were XXL-LS (5.16‰²), EH-GLG (3.40‰²), QL (2.31‰²), and the comparison of the fecal composition suggested their diet diversity, which might imply a degree of competitive pressure with sympatric animals. (3) Sichuan red pandas occupied a lower trophic position compared to other herbivores but higher than giant pandas in the same ecosystem, and the niche width of red pandas was two times larger than that of sympatric giant pandas, which was related to the foraging strategies and microhabitat selection of the giant and red panda. This research provides basic stable isotopic data for red pandas, offers scientific support for the differentiated and refined conservation and management of the red panda and its habitat, and develops the application of stable isotope analysis in the ecological studies of endangered species. Full article

This study evaluated tropical flower petals’ bioactive compounds and antioxidant and antimicrobial properties. The physicochemical characteristics, carotenoids, phenolics, anthocyanins, organic acids, and antioxidant activity of 67 flowers were analyzed. In addition, the antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus mutans, Candida albicans, and Candida tropicalis of 35 species was determined. A 2 × 3 experimental design was used for the extraction of carotenoids and phenolics, including solvents and ultrasonic agitation times. The mixture of methanol–acetone–dichloromethane (1:1:2) and acetone–methanol (2:1) resulted in the highest concentration of carotenoids, while acidified 80% methanol favoured phenolic extraction. Renealmia alpinia was extremely rich in carotenoids (292.5 mg β-carotene/g DW), Pleroma heteromallum in anthocyanins (7.35 mg C-3-gl/g DW), while a high content of citric acid was found in Hibiscus rosa-sinensis (17,819 mg/100 g DW). On the other hand, Thibaudia floribunda showed the highest antioxidant activity (7.8 mmol Trolox equivalent/g DW). The main phenolics were m-coumaric acid in Acalypha poiretii (12,044 mg/100 g DW), 4-hydroxybenzoic acid in Brugmansia arborea (10,729 mg/100 g DW), and kaempferol in Dahlia pinnata (8236 mg/100 g DW). The extract of Acalypha poiretii, Brownea macrophylla, and Cavendishia nobilis showed antibacterial activity, while the extract of Pleroma heteromallum was the only one active against Candida albicans. These findings highlight the potential health benefits from certain tropical flowers. Full article

Seed dormancy and germination are critical factors affecting oil palm production efficiency. The typical dormancy-breaking process involves dry heat treatment (38–40 °C for 40–60 days) followed by germination at 30–32 °C. To understand the molecular mechanisms behind this process and improve germination rates and speed, we conducted transcriptome analysis at three stages: pre-incubation, 45-day incubation at 40 °C, and 14-day germination at 32 °C. Our findings, supported by qRT–PCR and DEGs analysis, identified four key stages: ABA degradation, energy mobilization, starch mobilization, and cell elongation and division. ABA pathway genes (SnRK2, PYR/PYL) were active during dormancy release, while GAE and GPI were upregulated after heat treatment, indicating increased energy metabolism and structural changes. During germination, genes involved in starch/sucrose metabolism (SPS, TPP, SS, MGAM) and cell wall biosynthesis (GAUT1, PE, GAE) supported embryo expansion, with BAM, PGM, GlgB fueling early growth. Auxin (TIR1, AUX/IAA, ARF), brassinosteroid (BRI1, BSK, BIN2, CYCD3), ethylene (ETR, CTR1), and jasmonic acid (JAR1, COI1) pathway genes regulated cell growth and stress response, promoting seedling development. Though gibberellins were not crucial for this oil palm variety, gene expression varied between varieties. This study provides information on oil palm seed germination that could be applied to other oil palm species, particularly in terms of incubation times and chemical treatments. Full article

Glycogen, an α-glucan polymer serving as an energy storage compound in microorganisms, is synthesized through distinct pathways (GlgC-GlgA or GlgE pathway). Both pathways involve multiple enzymes, with a shared glycogen branching enzyme (GBE). GBEs play a pivotal role in establishing α-1,6-linkages within the glycogen structure. GBEs are also used for starch modification. Understanding how these enzymes work is interesting for both glycogen synthesis in microorganisms, as well as novel applications for starch modification. This study focuses on a putative enzyme GH13_9 GBE (PoGBE13), present in a polysaccharide utilization locus (PUL) of Pontibacter sp. SGAir0037, and related to the GlgE glycogen synthesis pathway. While the PUL of Pontibacter sp. SGAir0037 contains glycogen-degrading enzymes, the branching enzyme (PoGBE13) was also found due to genetic closeness. Characterization revealed that PoGBE13 functions as a typical branching enzyme, exhibiting a relatively high branching over non-branching (hydrolysis and α-1,4-transferase activity) ratio on linear maltooctadecaose (3.0 ± 0.4). Besides the GH13_9 GBE, a GH57 (PoGH57) enzyme was selected for characterization from the same PUL due to its undefined function. The combined action of both GH13 and GH57 enzymes suggested 4-α-glucanotransferase activity for PoGH57. The characterization of these unique enzymes related to a GlgE glycogen synthesis pathway provides a more profound understanding of their interactions and synergistic roles in glycogen synthesis and are potential enzymes for use in starch modification processes. Due to the structural similarity between glycogen and starch, PoGBE13 can potentially be used for starch modification with different applications, for example, in functional food ingredients. Full article

The biotechnology of converting methane to single-cell protein (SCP) implies using fast-growing thermotolerant aerobic methanotrophic bacteria. Among the latter, members of the genus Methylococcus received significant research attention and are used in operating commercial plants. Methylococcus capsulatus MIR is a recently discovered member of this genus with the potential to be used for the purpose of SCP production. Like other Methylococcus species, this bacterium stores carbon and energy in the form of glycogen, particularly when grown under nitrogen-limiting conditions. The genome of strain MIR encodes two glycogen synthases, GlgA1 and GlgA2, which are only moderately related to each other. To obtain glycogen-free cell biomass of this methanotroph, glycogen synthase mutants, ΔglgA1, ΔglgA2, and ΔglgA1ΔglgA2, were constructed. The mutant lacking both glycogen synthases exhibited a glycogen-deficient phenotype, whereas the intracellular glycogen content was not reduced in strains defective in either GlgA1 or GlgA2, thus suggesting functional redundancy of these enzymes. Inactivation of the glk gene encoding glucokinase also resulted in a sharp decrease in glycogen content and accumulation of free glucose in cells. Wild-type strain MIR and the mutant strain ΔglgA1ΔglgA2 were also grown in a bioreactor operated in batch and continuous modes. Cell biomass of ΔglgA1ΔglgA2 mutant obtained during batch cultivation displayed high protein content (71% of dry cell weight (DCW) compared to 54% DCW in wild-type strain) as well as a strong reduction in glycogen content (10.8 mg/g DCW compared to 187.5 mg/g DCW in wild-type strain). The difference in protein and glycogen contents in biomass of these strains produced during continuous cultivation was less pronounced, yet biomass characteristics relevant to SCP production were slightly better for ΔglgA1ΔglgA2 mutant. Genome analysis revealed the presence of glgA1-like genes in all methanotrophs of the Gammaproteobacteria and Verrucomicrobia, while only a very few methanotrophic representatives of the Alphaproteobacteria possessed these determinants of glycogen biosynthesis. The glgA2-like genes were present only in genomes of gammaproteobacterial methanotrophs with predominantly halo- and thermotolerant phenotypes. The role of glycogen in terms of energy reserve is discussed. Full article

Melon (Cucumis melo L.) is a valuable horticultural crop of the Cucurbitaceae family. Downy mildew (DM), caused by Pseudoperonospora cubensis, is a significant inhibitor of the production and quality of melon. Brassinolide (BR) is a new type of phytohormone widely used in cultivation for its broad spectrum of resistance- and defense-mechanism-improving activity. In this study, we applied various exogenous treatments (0.5, 1.0, and 2.0 mg·L⁻¹) of BR at four distinct time periods (6 h, 12 h, 24 h, and 48 h) and explored the impact of BR on physiological indices and the genetic regulation of melon seedling leaves infected by downy-mildew-induced stress. It was mainly observed that a 2.0 mg·L⁻¹ BR concentration effectively promoted the enhanced photosynthetic activity of seedling leaves, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis similarly exhibited an upregulated expression of the predicted regulatory genes of photosystem II (PSII) CmHCF136 (MELO3C023596.2) and CmPsbY (MELO3C010708.2), thus indicating the stability of the PSII reaction center. Furthermore, 2.0 mg·L⁻¹ BR resulted in more photosynthetic pigments (nearly three times more than the chlorophyll contents (264.52%)) as compared to the control and other treatment groups and similarly upregulated the expression trend of the predicted key enzyme genes CmLHCP (MELO3C004214.2) and CmCHLP (MELO3C017176.2) involved in chlorophyll biosynthesis. Meanwhile, the maximum contents of soluble sugars and starch (186.95% and 164.28%) were also maintained, which were similarly triggered by the upregulated expression of the predicted genes CmGlgC (MELO3C006552.2), CmSPS (MELO3C020357.2), and CmPEPC (MELO3C018724.2), thereby maintaining osmotic adjustment and efficiency in eliminating reactive oxygen species. Overall, the exogenous 2.0 mg·L⁻¹ BR exhibited maintained antioxidant activities, plastid membranal stability, and malondialdehyde (MDA) content. The chlorophyll fluorescence parameter values of F0 (42.23%) and Fv/Fm (36.67%) were also noticed to be higher; however, nearly three times higher levels of NPQ (375.86%) and Y (NPQ) (287.10%) were observed at 48 h of treatment as compared to all other group treatments. Increased Rubisco activity was also observed (62.89%), which suggested a significant role for elevated carbon fixation and assimilation and the upregulated expression of regulatory genes linked with Rubisco activity and the PSII reaction process. In short, we deduced that the 2.0 mg·L⁻¹ BR application has an enhancing effect on the genetic modulation of physiological indices of melon plants against downy mildew disease stress. Full article

Autophagy was initially recognized as a bulk degradation process that randomly sequesters and degrades cytoplasmic material in lysosomes (vacuoles in yeast). In recent years, various types of selective autophagy have been discovered. Glycophagy, the selective autophagy of glycogen granules, is one of them. While autophagy of glycogen is an important contributor to Pompe disease, which is characterized by the lysosomal accumulation of glycogen, its selectivity is still a matter of debate. Here, we developed the Komagataella phaffii yeast as a simple model of glycogen autophagy under nitrogen starvation conditions to address the question of its selectivity. For this, we turned the self-glucosylating initiator of glycogen synthesis, Glg1, which is covalently bound to glycogen, into the Glg1-GFP autophagic reporter. Our results revealed that vacuolar delivery of Glg1-GFP and its processing to free GFP were strictly dependent on autophagic machinery and vacuolar proteolysis. Notably, this process was independent of Atg11, the scaffold protein common for many selective autophagy pathways. Importantly, the non-mutated Glg1-GFP (which synthesizes and marks glycogen) and mutated Glg1^Y212F-GFP (which does not synthesize glycogen and is degraded by non-selective autophagy as cytosolic Pgk1-GFP) were equally well delivered to the vacuole and had similar levels of released GFP. Therefore, we concluded that glycogen autophagy is a non-selective process in K. phaffii yeast under nitrogen starvation conditions. Full article