Search Results (2,610)

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

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

Dendrobium officinale, an orchid of significant medicinal and ornamental value, exhibits poorly characterized hormonal regulation of flower bud differentiation. To address this knowledge gap, we employed an integrated multi-omics approach combining physiological, transcriptomic, metabolomic, and network analyses to elucidate the molecular mechanisms underlying the coordinated action of 6-Benzylaminopurine (6-BA) and Gibberellin A3 (GA₃) in this critical developmental process. Our key findings reveal that combined 6-BA and GA₃ treatment significantly enhances flower bud differentiation and induces stage-specific fluctuations in soluble sugar, protein, and starch levels. Transcriptomic profiling identified 11,994 differentially expressed genes (DEGs), with DEGs specific to the hormone-treated stage showing pronounced enrichment in plant hormone signal transduction and plant–pathogen interaction pathways. Metabolomic analysis uncovered 18 stage-specific differential metabolites (DAMs) during hormone treatment, including GA₃, 6-BA, and OPDA, whose accumulation dynamics were strongly correlated with the progression of differentiation. Weighted gene co-expression network analysis (WGCNA) pinpointed key hub genes within the yellow module, notably transcription factors from the C2H2, bZIP, and NAC families. Their interaction network demonstrated significant correlation with the transcriptional regulation of hormone-responsive genes. Significantly, this study establishes the first molecular framework for 6-BA and GA₃ regulation of flower bud differentiation in D. officinale. We demonstrate a metabolomic–transcriptomic coordination network driven by these hormones, where key hub genes form regulatory modules with transcription factors. Dynamic shifts in endogenous hormones reinforce the flowering signal. These findings provide crucial molecular targets for precision flowering control and molecular breeding strategies in orchids. Full article

Selenium can be absorbed and utilized by plants, influencing their growth by altering their physiological metabolism. In this study, based on plant physiology methods, compared to the CK treatment, the height and leaf length of oat seedlings under the T0.02 (0.02 g/kg Na₂SeO₃) treatment significantly increased by 18.36% and 15.81%, respectively (p < 0.05). Under the T0.1 (0.1 g/kg Na₂SeO₃) treatment, the levels of malondialdehyde (MDA), proline, soluble sugar content, and peroxidase (POD) activity significantly increased (p < 0.05). However, the seedling height and leaf length under the T0.1 treatment significantly decreased by 33.24% and 23.25%, respectively. Additionally, the contents of chlorophyll a, chlorophyll b, and carotenoids, as well as ascorbate peroxidase (APX) activity and the superoxide anion radical generation rate (O₂⁻) significantly decreased (p < 0.05). The total selenium, organic selenium, and inorganic selenium contents, as measured by the atomic fluorescence spectroscopy method, were also increased in oat seedling roots and leaves under T0.1 treatment (p < 0.05). Selenium had a high coefficient of mobility from root to leaf of 6.01 under T0.02 and 4.65 under T0.1 treatment, and from soil to leaf of 4.98 under T0.02 and 4.55 under T0.1 treatment. Through untargeted metabolomics, six differential phenylpropanoid compounds and 18 differential flavonoid compounds were found in oat seedlings. Based on transcriptomic analysis of oat seedlings, 29 DEGs associated with phenylpropanoid metabolism and 13 DEGs related to flavonoid biosynthesis were identified. Over 60% of the genes (25/42) in the phenylpropanoid and flavonoid biosynthesis pathway were associated with the accumulation of about 74% (20/27) of the compounds in oat leaves. Based on transcriptomic and metabolomics analysis, there were nine major genes (including PAL1, PAL4, CHS2, PAL7, POD3, PAL6, CCR1, CCR4, POD4) modulating the metabolism of phenylpropanoid and flavonoid biosynthesis pathway. This study offers novel insights and genetic resources for exploring the mechanisms underlying plant responses to selenium treatment, thereby further enhancing selenium tolerance in plants. Full article

A large population in Africa, particularly West Africa, depends on leafy vegetables such as red amaranth (Amaranthus cruentus), Lagos spinach (Celosia argentea), and African eggplant (Solanum macrocarpon) as affordable and readily available sources of nutrition. These vegetables are rich sources of phenolics, minerals, vitamins, and bioactive compounds, contributing significantly to dietary nutrition and providing an important source of revenue for farmers. However, the temperature rise due to climate change threatens their availability and nutritional value. This study assessed the effects of temperature regimes (23, 30, and 40 °C) on the growth and quality of these vegetables under greenhouse conditions for 48 (A. cruentus and C. argentea) and 54 (S. macrocarpon) days after sowing by measuring biomass (leaf, stem, shoot, root dry weight, root/shoot and leaf area), photosynthetic parameters, pigments, sugars, mineral content, antioxidant activity, total phenolic compounds, total flavonoids, and free amino acids. Temperature significantly affected biomass, with A. cruentus and C. argentea showing declines of 13.5–32.2% and 5.1–27.8%, respectively, at 40 °C compared to 23 °C, indicating sensitivity to heat stress. Photosynthetic rates increased with a rise from 23 to 30 °C by 2.1–29.2% across all species. Sugar contents remained generally stable, except for notable decreases in glucose and soluble sugars by 43.3% and 40.5%, respectively, in C. argentea between 30 and 40 °C, and a 52.6% reduction in starch in S. macrocarpon from 23 to 40 °C. Mineral nutrient responses varied by species; however, they exhibited similar increases in nitrogen and phosphorus, as well as decreases in calcium and manganese, at higher temperatures. Notably, antioxidant capacity and total phenolic compounds declined significantly in C. argentea (8.1% and 8.0%) and S. macrocarpon (4.7% and 13.3%). In contrast, free amino acid contents increased by 35.2% and 28.8% in A. cruentus and S. macrocarpon, respectively. It was concluded that A. cruentus and C. argentea suffer reduced growth and nutrients at 40 °C, while S. macrocarpon maintains biomass but has some biochemical declines; antioxidant capacity and phenolics drop at high temperatures, free amino acids rise, and 30 °C is optimal for all three. Full article

This study examined the physiological development of the red-fleshed peach cultivar ‘Daehong’ at different stages of fruit maturation to determine the optimal harvest time. Fruit samples were collected at five intervals—50, 80, 100, 120, and 140 days after full bloom (DAFBs)—and evaluated for external attributes (weight, size, and color) and internal attributes (soluble solids, sugar–acid ratio, firmness, sugars, and organic acids). Internal quality parameters, including soluble solids content and firmness, reached commercially acceptable levels at 120 DAFB. Sucrose was the predominant sugar, increasing steadily during maturation, while malic acid levels declined, resulting in an improved sugar–acid balance. Respiratory activity and ethylene production peaked at 140 DAFB, marking the onset of full ripening. Additionally, Hunter a* values and anthocyanin content increased progressively, intensifying the red coloration of the fruit. Principal component analysis (PCA) indicated that overall fruit quality was highest between 120 and 140 DAFB; however, reduced firmness at later stages suggests that delayed harvesting could impair postharvest storability. Considering both physiological indicators and climate variability, harvesting ‘Daehong’ peaches when growing degree days (GDDs) approach 1800 °C is recommended, as this provides a more consistent and objective maturity index than DAFB alone. Full article

To explore the mechanisms by which water, fertilizers, and dissolved oxygen affect the physiological growth and yield quality of custard apple, this study aims to optimize water–fertilizer–oxygen coupling regulation schemes for custard apple in dry hot valley regions through a multi-level fuzzy evaluation method, thereby addressing issues such as soil compaction and reduced aeration caused by long-term water and fertilizer drip irrigation. The experiment was conducted on custard apple in a dry, hot valley area, employing orthogonal and quadratic regression-orthogonal designs. Three factors were set at multiple levels: irrigation amount (60–100% ETc), fertilization rate (1500–1900 kg·ha⁻¹), and dissolved oxygen concentration (6–10 mg·L⁻¹). Custard apple development, production, and attributes were assessed. The two-year trial from 2023 to 2024 demonstrated that the new shoots, leaf area, and net photosynthetic rate of plants treated with W3F2O1 (100% ETc, 1700 kg·ha⁻¹ fertilization rate, and high oxygen 6 mg·L⁻¹) and W3F3O2 (100% ETC, 1500 kg·ha⁻¹ fertilization rate, and high oxygen 8 mg·L⁻¹) were significantly superior to those of W1F1O1 (60% ETc, 1900 kg·ha⁻¹ fertilization rate, and high oxygen 6 mg·L⁻¹), with a single-plant yield of 10.31 kg, and increases in diameter and length of 31.6% and 27.6%, respectively (p < 0.05); quality indicators were also optimal under W3F3O2 (100% ETC, 1500 kg·ha⁻¹ fertilization rate, and high oxygen 8 mg·L⁻¹) treatment, with soluble sugar and vitamin C levels increasing by 17.3% and 29.9%, respectively, compared to the control. Using a multi-level fuzzy evaluation to comprehensively evaluate the water–fertilizer–oxygen coupling, the comprehensive productivity of custard apples was significantly improved by optimizing the root zone microenvironment. It is recommended that dry hot valleys adopt an optimized range of 82.5–100% ETc irrigation, 1650–1847.86 kg·ha⁻¹ fertilization, and 7.4–9.25 mg·L⁻¹ dissolved oxygen, providing a theoretical basis for precise irrigation and sustainable cultivation of tropical fruit trees. Full article

Drought stress caused by continuous global warming poses a severe challenge to the growth and development of Nitraria tangutorum. Abscisic acid has an important regulatory function in the process of plants responding to drought stress. This study took the N. tangutorum seedlings of Zhangye provenance 2-17-16 genealogy as the research object to explore the physiological mechanism of how different concentrations of exogenous ABA alleviate drought damage in N. tangutorum. The results showed that exogenous ABA could promote the growth and increase the leaf relative water content of N. tangutorum seedlings under drought stress. It alleviates the photosynthetic inhibition phenomenon of N. tangutorum seedlings under drought stress by regulating the photoprotective mechanism and energy distribution efficiency of photosystem II. It also alleviates the drought damage of N. tangutorum by increasing the content of osmotic-adjustment substance contents such as soluble sugar, soluble protein, proline, and starch, as well as enhancing the activity of antioxidant enzymes such as POD, SOD, and CAT. The comprehensive analysis showed that 20 μM and 30 μM ABA have the best alleviating effects on the drought damage of N. tangutorum seedlings. This study provides a theoretical basis for the restoration, propagation, and protection of N. tangutorum, and it is of great significance for maintaining the balance and stability of desert ecosystems. Full article

Phyllostachys edulis is a vital bamboo resource in China, known for its economic benefits and ecological functions. However, under natural conditions, its seed germination rate is very low. Exogenous gibberellin (GA) directly supplements endogenous GA levels, while paclobutrazol (PAC) is an inhibitor of GA biosynthesis that can prevent seed germination. Preliminary experiment indicated that a treatment of 50 mg/L GA₃ markedly enhanced the germination rate of P. edulis seeds, whereas 50 μmol/L PAC had an opposite function. To study the exogenous GA₃ effects on the seed germination of P. edulis, seeds were soaked in ddH₂O (CK), Gibberellic acid 3 (GA₃), and PAC solutions for 24 h, respectively. Then, we analyzed and compared the physiology, biochemistry, and transcriptome at different germination stages. The results demonstrated that exogenous GA₃ treatment significantly reduced the contents of starch and soluble protein while increasing the levels of soluble sugar by inducing the activities of β-amylase and protease, respectively. In addition, the activities of superoxide dismutase (SOD), polyphenol (PPO), and ascorbate peroxidase (APX) were enhanced to eliminate ROS during seed germination under exogenous GA₃ treatment compared to CK and PAC treatments. Moreover, the endogenous levels of GA₃ and JA were found to be higher in exogenous GA₃-treated seeds than those in CK and PAC-treated seeds. Furthermore, RNA-seq results revealed that the expressions of 10 related genes are consistent with the observed physiological changes. In summary, exogenous GA₃ effectively accelerated the seed germination of P. edulis by influencing storage reserves, antioxidant enzymes activity, and endogenous hormone through the coordinated transcriptional regulation of related genes. These findings provide novel insights into the regulation mechanisms of exogenous GA₃ on the seed germination of P. edulis. Full article

Lithocarpus litseifolius, a traditional sweet tea rich in dihydrochalcones, relies on plant nutrients for secondary metabolite accumulation. However, nutrient distribution patterns during leaf development and its relationship with secondary metabolites remain inadequately characterized. This study examined mineral elements, carbon and nitrogen metabolites, and primary dihydrochalcones in L. litseifolius leaves at various developmental stages, and analyzed their interrelationships. Mineral nutrients such as phosphate (P), potassium (K), magnesium (Mg), zinc (Zn), boron (B), and copper (Cu), along with trilobatin, were most abundant in the youngest leaves. Conversely, calcium (Ca), iron (Fe), sulfur (S), manganese (Mn), selenium (Se), sugars, soluble protein, amino acids, chlorophyll, and carotenoids predominantly accumulated in old leaves, paralleling the distribution of phlorizin. Nitrogen (N) and molybdenum (Mo) concentrations were higher in mature leaves. In young leaves, P, K, Mg, S, Mn, Zn, and B positively correlated with phlorizin and trilobatin, while N, chlorophyll, carotenoids, and fructose correlated negatively. Trilobatin was the primary contributor to hydroxyl radical (·OH) scavenging capacity. Redundancy analysis highlighted N, P, Mg, B, Zn, Cu, Fe, Mo, and Se as key mineral nutrients influencing phlorizin and trilobatin accumulation. These findings offer insights for mineral nutrient management and effective utilization of L. litseifolius. Full article

Drought stress limits seedling growth, hindering morphological development and population establishment. Artocarpus nanchuanensis, a critically endangered species endemic to the karst regions of southwest China, exhibits poor population structure and limited natural regeneration in the wild, with water deficit during the seedling stage identified as a major factor contributing to its endangered status. Elucidating the physiological and molecular mechanisms underlying drought tolerance in A. nanchuanensis seedlings is essential for improving their drought adaptability and facilitating population recovery. In this study, 72 two-year-old seedlings were divided into two groups: drought (PEG) and ethephon (PEG + Ethephon), and subjected to drought-rehydration experiments. The results showed that exogenous application of 100 mg·L⁻¹ ethephon significantly improved stomatal conductance and photosynthetic pigment content in A. nanchuanensis seedlings. Under drought stress, the PEG + Ethephon group exhibited rapid stomatal closure, maintaining water balance and higher photosynthetic pigment levels. After rehydration, the PEG + Ethephon group significantly outperformed the PEG group in terms of photosynthetic rate. Ethephon treatment reduced H₂O₂ and MDA levels, enhanced antioxidant enzyme activity (SOD, CAT, POD, GR), and increased osmotic regulator activity (soluble sugars, soluble proteins, and proline), improving ROS-scavenging capacity and reducing oxidative damage. Ethephon application significantly enhanced ethylene accumulation in seedlings, while drought stress stimulated the concentrations of key ethylene biosynthetic enzymes (SAMS, ACS, and ACO), thereby further contributing to improved drought resistance. Transcriptomic data revealed that drought stress significantly upregulated key ethylene biosynthesis genes, with expression levels increasing with stress duration and rapidly decreasing after rehydration. WGCNA analysis identified eight key drought-resistance genes, providing valuable targets for future research. This study provides the first mechanistic insight into the physiological and molecular responses of A. nanchuanensis seedlings to drought and rehydration, underscoring the central role of endogenous ethylene in drought tolerance. Ethephon treatment effectively enhanced ethylene accumulation and biosynthetic enzyme activity, thereby improving drought adaptability. These findings lay a theoretical foundation for subsequent molecular functional studies and the conservation biology of this endangered species. Full article

Silicon plays a positive role in plant growth and physiological activities; however, silicon fertilizer application in bamboo remains limited. This study explored the silicon accumulation and photosynthetic capacity of Dendrocalamus brandisii in response to sodium silicate (SS) foliar application across vegetative phenological stages. The results showed that August (shooting stage) and May (branching and leafing stage) were the critical periods for silicon accumulation. SS significantly enhanced the net photosynthetic rate (Pn), chlorophyll content, and photosystem activity (Fv/Fm, Fv′/Fm′), particularly in August and May. Correlation analysis revealed that silicon content was significantly positively correlated with photosynthetic parameters (Pn, chlorophyll a/b) and photoassimilate accumulation (soluble sugar, starch), confirming that silicon optimized leaf light capture and carbon assimilation capacity by promoting phytolith formation. This research provides a theoretical foundation for the application of silicon fertilizers in bamboo forest cultivation. Full article

Soluble sugars, primarily fructose, glucose, sucrose, and sorbitol, are crucial determinants of fruit flavor and quality. As a core component of biological metabolism, sugar metabolism provides energy and carbon for fruit development, ultimately governing carbohydrate accumulation in mature fruits. This process requires the coordinated activities of multiple enzymes and transporters, modulated by the spatiotemporal expression patterns of their encoding genes. Therefore, it is essential to elucidate both the activities of these enzymes across different fruits and their underlying gene expression patterns. While significant progress has been made in functional genes involved in soluble sugar metabolism and deciphering their regulatory networks, an overall introduction of this knowledge remains lacking. This review presents an integrative analysis of soluble sugar accumulation during fruit development, encompassing spatiotemporal dynamics of key metabolic enzymes, functional characterization of encoding genes, signaling response mechanisms governing gene regulation, and the overarching genetic network. Full article

Strawberry is a popular fruit with great commercial value. It is meaningful to study how to improve strawberry yield and quality in a sustainable way. In this research, the potential impacts of replacing chemical fertilizer (CF) with sheep manure organic fertilizer (SMOF) on strawberry rhizospheric bacteria, soil physicochemical properties, strawberry fruit yield, and nutritional quality were studied through a strawberry field experiment with 16 years of different fertilizer applications. This study showed that, compared with chemical fertilizer, SMOF effectively improved soil physicochemical properties and increased the relative abundance of beneficial bacteria, the absolute abundance of phosphorus-related functional genes pqqC and phoD and bacteria diversity, and enhanced synergistic action among strawberry rhizospheric bacteria. The yield, and the contents of total soluble solids, soluble sugar, soluble protein, and vitamin C, and sugar/acid ratio of strawberry fruit in SMOF treatment were significantly higher than in CF treatment by 40%, 21%, 15%, 46%, 23%, and 41%, respectively (p < 0.05). Pearson correlation coefficient analysis showed that strawberry fruit yield and nutritional quality were positive with soil pH, bacterial diversity, soil enzyme activity, and nutrient content, and negative with soil density. The results showed that long-term SMOF could efficiently improve strawberry performance and rhizospheric health. Full article

Sugar transporters of the SWEET family are essential for plant growth, development, yield formation, and stress responses by regulating sugar transport and distribution. This study characterizes the function and expression characteristics of CoSWEET2a, a Clade I SWEET gene in Camellia oleifera. We conducted subcellular localization, functional complementation in Arabidopsis, sugar response assays, drought tolerance tests, and hormone induction analysis. A key finding is CoSWEET2a, which that is localized on the vacuolar membrane in Camellia oleifera. Heterologous expression in Arabidopsis atsweet2 mutants revealed sugar-specific effects on root growth. Moreover, expression of CoSWEET2a increased soluble sugar content in Arabidopsis seeds. Additionally, CoSWEET2a overexpression enhanced drought stress tolerance by augmenting sugar content. The expression of CoSWEET2a is regulated by gibberellin (GA) and abscisic acid (ABA), and its promoter contains corresponding hormone response elements. In conclusion, CoSWEET2a functions as a “sugar buffer” on the vacuolar membrane, regulating sugar accumulation, root development, and drought stress responses. This discovery not only reveals that vacuolar SWEET plays an important role in maintaining cytoplasmic sugar homeostasis in plants but also provides a direct genetic target for engineering high-quality, drought-tolerant crops. Full article