Search Results (1,144)

Cowpea (Vigna unguiculata L. Walp.) is a species with superior tolerance to drought stress compared to other legumes. It is a promising crop with increasing importance in the face of global climate changes. Local forms, well adapted to particular agro-climatic conditions, are useful germplasm resources. Five Bulgarian cowpea landraces, which had displayed differences in osmotic stress tolerance at the germination stage, were subjected to severe stress (15% PEG 6000 in Hoagland nutrient media) during 16 days at the vegetative growth stage (plants with expanded trifoliate leaves). All local forms responded to the imposed stress by biomass and leaf area diminution, a slight increase in leaf water deficit and electrolyte leakage, proline accumulation in roots and leaves, and an increase in root starch and leaf phenol content. Roots presented more pronounced metabolic changes than leaves, including increased total antioxidant activity, phenolic and carbohydrate content, and proline accumulation. Under osmotic stress, tight control of oxidative stress and concerted upregulation of superoxide dismutase, catalase, glutathione transferase, and peroxidase activities in leaves were registered along with changes in certain specific isoforms, while glutathione reductase activity diminished. Antioxidant enzyme activities had different changes in stressed roots, compared to leaves, and among genotypes. The accession most sensitive to osmotic stress at germination presented more symptoms of oxidative stress at the vegetative growth stage. Full article

Anthocyanins (ACNs) are flavonoid pigments that accumulate in plants and respond to environmental stimuli, including low phosphorus (LP). The synthesis and stable accumulation of ACNs rely on substantial carbohydrate investment, implying a potential role in carbon partitioning-mediated growth and resistance, in addition to the well-established antioxidant activity. To investigate cultivar-dependent differences in ACN accumulation and their relationship with photo-assimilate partitioning and growth adaptation under LP stress, seedlings of six representative maize cultivars were hydroponically cultured under both control and LP conditions. ACNs content, photosynthetic parameters, plant relative growth ratio, and tissue-specific carbohydrates were quantified. The results showed that LP reduced photosynthesis and biomass, while stimulating ACNs biosynthesis in leaves and sheaths. Cultivars were then classified as ACN-sensitive and -insensitive groups based on the ACNs accumulation in the newly unfolded leaves and corresponding sheaths. ACN-sensitive cultivars exhibited higher ACNs levels, which correlated positively with soluble sugars but negatively with starch reserves, suggesting preferential carbon partitioning to ACNs precursors rather than to starch. These cultivars also maintained higher relative growth ratios under LP, associated with less photosynthesis decline and starch accumulation compared with ACN-insensitive cultivars. We hypothesize that ACNs synthesis function as a diversion of photo-assimilates into secondary metabolism under LP, thereby improving photosynthetic efficiency by mitigating excess sugar accumulation that could impair plant growth. This carbon-partitioning adaptation could be exploited by selecting for ACNs accumulation as a breeding trait to enhance maize resilience to LP. Full article

Background/Objectives: Alcoholic liver disease (ALD) is intricately linked to gut microbiota dysbiosis and metabolic disturbances along the gut–liver axis. Octenyl succinic anhydride (OSA) starch escapes digestion in the small intestine and ferments in the colon, modulating gut microbiota and metabolism. This study explored the protective effects of OSA starch against ALD and elucidated the underlying gut microbiota–metabolite interactions. Methods: A chronic ethanol-fed mouse model was conducted to evaluate the protective effects of OSA starch against ALD, and multi-omics analyses integrating 16S rRNA sequencing, PICRUSt2 functional predictions, and metabolomics were used to reveal potential mechanism. Results: OSA starch supplementation in ALD mice significantly reduced liver fat accumulation, lowered the liver index to 4.11%, and restored serum transaminase levels closer to normal. Multi-omics analyses revealed that OSA starch enriched beneficial gut bacteria such as Faecalibaculum rodentium and Bifidobacterium adolescentis. OSA starch also enhanced microbial metabolic functions, including pyruvate, butanoate, and propanoate metabolism. These shifts were accompanied by regulation of fecal and serum metabolites, including pyruvate, 2-hydroxybutanoic acid, and lactic acid. Structural equation modeling further confirmed that OSA starch ameliorates ALD via coordinated modulation of gut microbiota, microbial functions, metabolites, and serum markers. Conclusions: OSA starch protects against alcoholic liver injury by remodeling the gut–liver metabolic network, presenting a promising dietary strategy for ALD. Full article

To elucidate shade adaptation mechanisms in Pinus yunnanensis seedlings across different ages, this study established five light gradients (100% full sunlight as control or CK, 80% as L1, 45% as L2, 30% as L3, and 5% as L4) for experimental treatments on one- and three-year-old seedlings. By analyzing dynamic changes in non-structural carbohydrates (NSCs) and their components within needles, stems, and roots—combined with a phenotypic plasticity assessment, a correlation analysis, and a principal component analysis—we explored the carbon metabolic adaptations under shade stress. The key results demonstrate the following: (1) Increasing shade intensity significantly reduced the NSCs in the needles and roots of both age groups. The stem NSCs markedly decreased under L1 and L2, indicating “carbon limitation.” However, under severe shade (L3 and L4), the stem NSCs stabilized while the stem soluble sugars gradually increased. In three-year-old Pinus yunnanensis seedlings under the L3 treatment, the ratio of soluble sugars to starch in the stems reached as high as 5.772 g·kg⁻¹, yet the stem NSC content showed no significant change. This pattern exhibited “growth stagnation-carbon enrichment” characteristics. This reveals a physiological strategy for maintaining stem carbon homeostasis through a “structure–metabolism” trade-off under carbon limitation. (2) Shade adaptations diverged by age: one-year-old seedlings employed a short-term “needle–root source–sink reallocation” strategy, whereas three-year-old seedlings developed a “root–stem–needle closed-loop homeostasis regulation” mechanism. (3) Age-specific shade thresholds were identified: one-year-old seedlings required >80% full light to maintain a carbon balance, while three-year-old seedlings exhibited enhanced root carbon storage under moderate shade (45–80% full light). This study clarifies the physiological mechanisms by which P. yunnanensis seedlings of varying ages optimize shade adaptation through organ-specific carbon allocation, providing a theoretical foundation for shade management in artificial forests and understory seedling conservation. Full article

Constrained by site conditions and water resources, pear tree cultivation faces increasing drought stress. Paecilomyces variotii extract (PVE), a novel biostimulant extracted from wild sea buckthorn root-isolated strains and containing chitin, humic/fulvic acids, and beneficial microbes, has gained attention due to its high activity and efficacy in alleviating plant stresses (e.g., drought). In this study, Pyrus pyrifolia ‘Qiu Yue’ was used as the experimental material, and pot experiments were conducted to examine the drought-mitigating effects of different PVE concentrations. Drought stress was achieved by maintaining soil water content at 35–45% of water holding capacity for 45 days under natural evaporation conditions in rain shelters. The growth status of pear trees, soil enzyme activity, and metabolite levels were analyzed. The results showed that the application of 5 ng/mL PVE promoted pear tree growth, enhanced leaf antioxidant enzyme activity, and improved photosynthetic capacity and soil enzyme activity. Under normal water conditions, the shoot growth length, plant height, stem diameter, and root system activity of the 5 ng/mL PVE group were 31.91%, 12.05%, 3.54%, and 10.94% higher than those of the control group, respectively. Under drought stress, these values increased by 25.12%, 8.87%, 12.21%, and 16.98%, respectively. The addition of 5 ng/mL PVE facilitates trehalose release and upregulates starch-sucrose, glycerophospholipid, and galactose metabolic pathways, thereby potentiating drought stress tolerance in pear trees. However, at 20 ng/mL, reductions were observed in pear tree growth indicators, leaf antioxidant enzyme activity, soil enzyme activity, and trehalose content in root exudates compared to the 5 ng/mL PVE treatment. Overall, 5 ng/mL PVE effectively promotes pear tree growth and enhances drought resistance, making it suitable for broader use in pear cultivation practices. Full article

Starch serves as a crucial storage substance in both cereal crops and root/tuber crops, with its composition and properties determining the quality of storage organs. The Waxy (Wx) gene, encoding a key enzyme in starch biosynthesis, plays a pivotal role in this metabolic pathway. However, existing reviews seldom systematically elaborate on Wx gene regulatory mechanisms from the perspective of intrinsic molecular networks. Focusing on the model crop rice, this article synthesizes research advances in Wx-mediated starch biosynthesis regulation over the past decade. We analyze the structural features of the Wx gene and factors influencing its regulatory function during starch synthesis. In conclusion, future research directions are proposed to provide references for Wx gene studies in other crops, as well as theoretical foundations for rice varietal improvement and molecular design breeding. Full article

The germination and elongation of maize in the early growth stage are closely related to the elongation of the mesocotyl, which is one of the first parts to sense external temperature, aside from the coleoptile. Low-temperature (LT, 10~15 °C) stress can significantly affect the survival and growth of maize seedlings. Additionally, brassinosteroids (BRs) have been used in recent years to help alleviate damage caused by LT in various plants. However, the interaction among LT, BRs, and sugar remains unclear. Therefore, we examined the relationships among the contents of glucose, sucrose, and starch, along with the changes in differentially expressed genes (DEGs) involved in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways. Compared to CK (0 μM 24-epibrassinolide (EBR) application at 25 °C), the contents of glucose and sucrose increased by 0.26, 0.47, and 0.70 mg g⁻¹ FW and 0.80, 0.30, and 0.61 mg g⁻¹ FW, respectively, under the CKE (2.0 μM 24-epibrassinolide (EBR) application at 25 °C), LT (0 μM 24-epibrassinolide (EBR) application at 10 °C), and LTE (2.0 μM 24-epibrassinolide (EBR) application at 10 °C) treatments. However, starch contents decreased under LT and LTE treatments, by −20.54% and −0.20%, respectively, compared to CK. This suggests that sugar signaling and metabolism play key roles in regulating LT tolerance, and the application of EBR may alleviate LT damage by regulating sugar accumulation levels. Furthermore, 108 DEGs were identified in the starch and sucrose metabolism pathways, along with 23 in glycolysis, with 65 DEGs at the transcriptome level. The common Zm00001d042146 (hexokinase-3) in both pathways is usually down-regulated, and the degree of down-regulation when EBR is added is less than under LT alone. Additionally, key genes such as Zm00001d021598 (glucan endo-1,3-beta-glucosidase 3), Zm00001d034017 (uncharacterized LOC541703), and Zm00001d029091 (sucrose synthase 2) were differentially expressed under LT, with their expression levels decreasing further when EBR was added. In conclusion, our results provide a new direction into the molecular mechanisms by which exogenous EBR application enhances low-temperature tolerance in maize seedlings. Full article

Improving agricultural by-product utilization can alleviate tropical feed shortages. This study used corn stover (CS, Zea mays L.) at the maturity stage as the material, with four silage treatments: control, lactic acid bacteria (LAB, Lactiplantibacillus plantarum), cellulase (AC, Acremonium cellulolyticus), and LAB+AC. After 60 days fermentation in plastic drum silos, the silos were opened for sampling. PacBio single-molecule real-time sequencing technology was used to study bacterial community structure, symbiotic network functionality, and pathogenic risk to clarify CS fermentation regulatory mechanisms. The CS contained 59.9% neutral detergent fiber and 7.1% crude protein. Additive-treated silages showed better quality than the control: higher lactic acid (1.64–1.83% dry matter, DM), lower pH (3.62–3.82), and reduced ammonia nitrogen (0.54–0.81% DM). Before ensiling, the CS was dominated by Gram-negative Rhizobium larrymoorei (16.30% of the total bacterial community). Functional prediction indicated that the microbial metabolism activity in diverse environments was strong, and the proportion of potential pathogens was relatively high (14.69%). After ensiling, Lactiplantibacillus plantarum as Gram-positive bacteria were the dominant species in all the silages (58.39–84.34% of the total bacterial community). Microbial additives facilitated the establishment of a symbiotic microbial network, where Lactiplantibacillus occupied a dominant position (p < 0.01). In addition, functional predictions showed an increase in the activity of the starch and sucrose metabolism and a decrease in the proportion of potential pathogens (0.61–1.95%). Among them, the synergistic effect of LAB and AC inoculants optimized the silage effect of CS. This study confirmed that CS is a potential high-quality roughage resource, and the application of silage technology can provide a scientific basis for the efficient utilization of feed resources and the stable development of animal husbandry in the tropics. Full article

Drought stress significantly limits crop growth and yield, and the mechanisms underlying genotypic variation in drought tolerance remain unclear. This study investigated the growth and transcriptomic responses of two sorghum varieties, drought-sensitive Jinza 35 (V1) and drought-tolerant Longza 24 (V2), under drought conditions. Comparative transcriptomic analysis, along with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, revealed distinct molecular mechanisms between the two varieties. Both varieties exhibited drought-responsive changes in photosynthesis-related pathways. However, the drought-tolerant V2 showed significant enrichment in phenylpropanoid biosynthesis, starch-sucrose metabolism, and plant hormone signaling pathways, suggesting enhanced metabolic flexibility under stress. In contrast, V1 primarily activated ribosome metabolism and cell cycle regulation pathways, indicating a less adaptive response focused on basic cellular processes. These findings highlight key metabolic and regulatory differences underlying drought tolerance in sorghum. The study provides valuable molecular insights and candidate pathways for future functional studies and the breeding of drought-resistant sorghum varieties. Full article

Soluble sugars are among the key components determining the flavor quality of rapeseed bolting. However, the potential regulatory network governing the biosynthesis of soluble sugars during the growth and development of rapeseed bolting remains largely unknown. In this study, the total soluble sugar and starch contents were measured at the seedling and bolting stages in 203 Brassica napus germplasms. Among them, the inbred lines No51 and No106 were identified as high- and low-sugar materials, respectively. A comparative analysis of the soluble sugar composition between these two extreme lines revealed that sucrose and glucose are the key metabolites contributing to differences in the soluble sugar content. A total of 36,893 differentially expressed genes (DEGs) were identified by transcriptomics, including 19,031 significantly upregulated genes and 17,862 downregulated genes. Metabolomics has identified 25 common and unique metabolites. The combined analysis of transcriptomics and metabolomics showed that differentially expressed genes and metabolites were mainly concentrated in starch and sucrose metabolism, galactose metabolism, and the interconversion of pentose and glucuronic acid. The expression patterns obtained by RNA seq and qRT PCR are highly consistent. A regulatory network related to soluble sugar synthesis and metabolism was constructed, leading to the identification of BnaC02G0100500ZS, BnaC02G0100700ZS, and BnaC02G0092700ZS as potential key genes involved in the regulation of soluble sugar biosynthesis. Full article

This study investigated the effects of light intensity regulation on yield and energy efficiency during potato pre-basic seed propagation in plant factories. Using virus-free ‘Favorita’ potato seedlings as experimental material, gradient light intensities (200, 300, and 400 μmol·m²·s⁻¹) were applied at four developmental stages: the seedling stage (SS), tuber formation stage (TFS), tuber growth stage (TGS), and harvest stage (HS), to explore the physiological mechanisms of stage-specific light intensity regulation and energy utilization efficiency. The results revealed that: (1) The per-plant tuber yield of the high yield group reached 72.91 g (T59 treatment), representing a 25% increase compared to the medium yield group and a 168% increase compared to the low yield group. Additionally, the high yield group exhibited superior leaf area, photosynthetic rate, and accumulation of sucrose and starch. (2) The impact of light intensity on tuber development exhibited stage specificity: low light intensity (200 μmol·m⁻²·s⁻¹) during TFS promoted early tuber initiation, while a high light intensity (400 μmol·m⁻²·s⁻¹) enhanced tuber formation efficiency. Increasing the light intensity during TGS facilitated the accumulation of sucrose and starch in tubers. (3) Energy use efficiency (EUE) increased significantly with yield, with the high yield group reaching 3.2 g MJ⁻¹, representing 52% and 88% improvements over the medium yield (2.1 g MJ⁻¹) and low yield (1.7 g MJ⁻¹) groups, respectively. A “stage-specific precision light supplementation” strategy was proposed, involving moderate light reduction (200 μmol·m⁻²·s⁻¹) during TFS and light enhancement (300 μmol·m⁻²·s⁻¹) during TGS to coordinate source-sink relationships and optimize carbohydrate metabolism. This study provides a theoretical basis for efficient potato production in plant factories. Full article

Chlorophyll, the green pigment essential for photosynthesis, abundantly found in green vegetables and algae, has attracted growing scientific interest for its potential therapeutic effects, particularly in diabetes management. Recent research highlighted that chlorophyll and its derivatives may beneficially influence glucose metabolism and oxidative stress, key factors in diabetes. This review examines current knowledge on how chlorophyll compounds could aid diabetes control. Chlorophyll and its derivatives appear to support glucose regulation primarily through actions in the gastrointestinal tract. They modulate gut microbiota, improve glucose tolerance, reduce inflammation, and alleviate obesity-related markers. While chlorophyll itself does not directly inhibit digestive enzymes like α-glucosidase, its derivatives such as pheophorbide a, pheophytin a, and pyropheophytin a may slow carbohydrate digestion, acting as α-amylase and α-glucosidase inhibitors, reducing postprandial glucose spikes. Additionally, chlorophyll enhances resistant starch content, further controlling glucose absorption. Beyond digestion, chlorophyll derivatives show promise in inhibiting glycation processes, improving insulin sensitivity through nuclear receptor modulation, and lowering oxidative stress. However, some compounds pose risks due to photosensitizing effects and toxicity, warranting careful consideration. Chlorophyllin, a stable semi-synthetic derivative, also shows potential in improving glucose and lipid metabolism. Notably, pheophorbide a demonstrates insulin-mimetic activity by stimulating glucose uptake via glucose transporters, offering a novel therapeutic avenue. Overall, the antioxidant, anti-inflammatory, and insulin-mimicking properties of chlorophyll derivatives suggest a multifaceted approach to diabetes management. While promising, these findings require further clinical validation to establish effective therapeutic applications. Full article

Background: Artocarpus heterophyllus, familiar as jackfruit, is a tropical fruit highly valued not only for its nutritional content but also for its medicinal properties, including potential antidiabetic effects. Objectives: This study aimed to evaluate the insulinotropic, β-cell proliferative and anti-hyperlipidaemic properties of the ethanol extract of unripe Artocarpus heterophyllus (EEAH) in high-fat-fed (HFF) diet-induced obese mice. Method: We evaluated acute insulin secretion and β-cell proliferation in BRIN-BD11 cells, and assessed in vitro glucose diffusion and starch digestion. In vivo, acute and chronic studies in HFF induced obese mice measured glucose tolerance, body weight, food and fluid intake, and lipid profiles. A preliminary phytochemical screening was also performed. Results: In this study, EEAH exhibited significant antidiabetic activity through multiple mechanisms. EEAH enhanced glucose-stimulated insulin secretion in BRIN-BD11 β-cells via K_ATP channel modulation and cAMP-mediated pathways, with partial dependence on extracellular calcium, and it also promoted β-cell proliferation. In vitro assays revealed its ability to inhibit starch digestion and glucose diffusion, indicating delayed carbohydrate digestion and absorption. In high-fat-fed (HFF) obese mice, the acute and chronic oral administration of EEAH improved oral glucose tolerance, reduced fasting blood glucose, decreased body weight, and normalized food and fluid intake. Lipid profile analysis showed increased HDL and reduced total cholesterol, LDL, and triglycerides, while higher doses of EEAH also enhanced gut motility. Phytochemical screening revealed the presence of bioactive compounds such as alkaloids, tannins, flavonoids, saponins, steroids, and terpenoids, which are likely responsible for these therapeutic effects. Conclusion: These findings highlight EEAH as a promising natural candidate for adjunctive therapy in managing type 2 diabetes and associated metabolic disorders and emphasize the importance of future multi-omics studies to elucidate its molecular targets and pathways. Full article

Off-white or yellowish shoots are common in tea plants (Camellia sinensis L.), and such albino variations are often accompanied by metabolic reprogramming, including increased contents of amino acids and lower levels of polyphenols. Nonetheless, the molecular mechanisms that underlie these albino variations remain to be fully clarified. Here, we examined the ultrastructural characteristics of novel, naturally occurring, yellowish mutated tea leaves and performed metabolomic analyses on green and albino leaves and stems. Then, transcriptomic analyses were also conducted on green and albino leaves to investigate the mechanistic basis of the albino variation. As expected, the cells of albino tea leaves contained fewer and smaller chloroplasts with disorganized thylakoids and smaller starch granules. Widely targeted metabolomics analysis revealed 561 differentially abundant metabolites between green and albino leaves and stems, but there was little difference between green and albino stems. Then, RNA sequencing of green and albino leaves revealed downregulation of genes associated with light harvesting and photosynthesis, and integration of the metabolomic and transcriptomic results indicated that biosynthesis of aromatic amino acids (AAAs) was strongly upregulated in albino leaves. To gain additional insight into the molecular basis of the increased AAA levels, Oxford Nanopore long-read sequencing was performed on green and albino leaves, which enabled us to identify differences in long non-coding RNAs (lncRNAs) and alternatively spliced transcripts between green and albino leaves. Interestingly, the amino acid biosynthesis genes arogenate dehydratase/prephenate dehydratase (ADT) and serine hydroxymethyltransferase (SHMT) were highlighted in the lncRNA and alternative splicing analyses, and the transcription factor genes PLATZ, B3 Os04g0386900, and LRR RLK At1g56140 showed significant changes in both expression and alternative splicing in albino leaves. Together, our data suggest that biosynthesis of AAAs might be crucial for albino mutations in tea plants and could be coordinated with the regulation of lncRNAs and alternative splicing. This is a complex regulatory network, and further exploration of the extensive metabolic reprogramming of albino tea leaves will be beneficial. Full article

Potato tuber (Solanum tuberosum L.) was prone to greening and quality deterioration during postharvest storage due to various factors, affecting the regulation of chlorophyll biosynthesis. In the present study, potato tubers were placed at 600 lux and 25 °C after sodium alginate—xanthan gum—glycerin composite coating. During storage, the apparent color changes and a* value of the surface were observed and determined, meanwhile the contents of nutrients, chlorophyll, and its intermediates in photosynthetic metabolism were analyzed. The results showed that after 9 d, compared to the control group, the sodium alginate coating treatment significantly inhibited greening, delayed the decline of appearance quality and nutrients including dry matter, starch, reducing sugar, soluble protein, and ascorbic acid. Furthermore, the sodium alginate coating promoted the contents of 5-aminolevulinic acid (ALA) (1.33 fold), porphobilinogen (PBG) (1.06 fold), and uroporphyrinogen III (Uro III) (1.07 fold), meanwhile, inhibited the production of protoporphyrin IX (Proto IX) (13.86%), Mg-protoporphyrin IX (Mg-Proto IX) (14.15%) and protochlorophyllide (Pchlide) (25.97%), which were key intermediates in the chlorophyll synthesis, indicating that the sodium alginate coating delay the greening by blocking the conversion of Uro III to Proto IX. These results provided valuable insights for the postharvest preservation of potato tuber. Full article