China Federation of Supply and Marketing Cooperatives

Open-central canopy (OCC) has become the popular tree shape for arboreal apple orchards in full fruit period in the Loess Plateau of China. This study aimed to elucidate the physiological regulation mechanisms related to planting density optimization, photosynthetic performance enhancement, and fruit quality improvement in dense-canopy OCC apple orchards in the Loess Plateau of China through tree thinning practices at different intensities. This study used three planting densities of OCC apple trees as experimental materials. These include no thinning [NT, 3 m (plant) × 4 m (row)], low-intensity thinning [LT, i.e., first thinning based on NT: 4 m (plant) × 6 m (row)], and high-intensity thinning [HT, i.e., second thinning based on LT: 6 m (plant) × 8 m (row)]. In three successive experimental years, changes in spatiotemporal variations of photosynthetically active radiation ( PAR ) intercepted by canopy, leaf gas exchange, gross photosynthetic rate ( P g ), photorespiration rate ( P r ), nonphotochemical quenching ( NPQ ) dark relaxation curves, antioxidant enzyme activity [ascorbate peroxidase, catalase and superoxide dismutase (SOD)], and fruit quality were carefully measured and compared. Results showed that compared with NT, LT increased PAR by 36%, maximum net photosynthetic rate under light saturation ( P nmax,P ) by 30%, carboxylation efficiency ( CE ) by 37%, fruit soluble solid content (SSC) by 4%, and peel anthocyanin content (AC) by 20%. Moreover, LT enhanced the photoprotective capacity through elevated ratio of P r to P g under PAR of 2 000 μmol · m −2 · s −1 (52%), the reversible component in NPQ [r( q E), 9%], and antioxidant enzymes (SOD 10%). Compared with NT, HT enhanced PAR by 71%, P nmax,P by 67%, CE by 65%, SSC by 9%, and AC by 37% and boosted photoprotection through increased P r / P g (116%), r( q E) (11%), and SOD activity (29%). The Pearson Correlation Coefficients between PAR and the fruit quality indices (including single fruit weight, SSC, and AC) were 0.89, 0.73, and 0.96, respectively. Single fruit weight and SSC were significantly and positively correlated with photosynthetic parameters (such as P nmax,P and CE ). In summary, after tree thinning, the light environment in the OCC of apple trees was remarkably improved, and the leaf photosynthetic and photoprotective capacities were enhanced, thus significantly boosting fruit qualities. In terms of the dose responses, high-intensity thinning demonstrated the most significant enhanced effects.

Low-grade tea, often underutilized due to its coarse texture and limited bioavailability, represents a significant resource waste. This study systematically investigated the synergistic effects of steam explosion (SE) and superfine grinding on enhancing the structural deconstruction, powder property, instant solubility, and diffusivity of low-grade. SE treatment induced critical physicochemical modifications, including hemicellulose degradation, lignin recondensation, and cellulose crystalline reorganization, which significantly weakened the lignocellulosic matrix. Subsequent superfine grinding via ball milling achieved ultrafine particles, with median diameter D50 = 10.4 ± 0.17 μm, and almost completely destroyed the cell wall by 99.9%. Extraction kinetics revealed that SE-ball milling synergistically accelerated the diffusion behavior of bioactive compounds, reducing equilibrium time by 2~4 times and increasing maximum yields of polysaccharides, polyphenols, caffeine, and water-soluble solids by 9~25% compared to untreated samples. Homogenization combined with 0.08 mg/mL CMC-Na further improved the suspension stability of tea powder and reduced its centrifugal sedimentation to 9.85%. These findings demonstrate a scalable strategy to transform low-grade tea into high-value ingredients with enhanced accessibility and solubility of bioactive compounds, offering promising applications in instant beverages, fortified foods, and nutraceuticals.

Functional constipation ranks among the most common disorders impacting human health, which is manifested by difficulty in defecation and a complex etiology. L-Arabinose, a pentose found naturally in fruit rinds and cereal husks, has been reported to regulate glycolipid metabolism, improve glucose homeostasis, and exhibit anti-inflammatory effects. However, the effect and precise mechanism of L-Arabinose on functional constipation remain unclear. In this study, the effect of L-Arabinose in alleviating functional constipation induced by diphenoxylate was evaluated. The model group consisted of functional constipation mice that did not receive any intervention. The positive drug group was treated with 2.0 g/kg lactulose, while the intervention group was given 0.5 g/kg, 0.75 g/kg, 1.0 g/kg, and 2.0 g/kg L-Arabinose, respectively. The data suggested that 20 days of L-Arabinose intervention could shorten the first black stool defecation time, increase fecal water content, and enhance the rate of small intestinal propulsion in mice with functional constipation induced by diphenoxylate. Additionally, L-Arabinose reversed the protein expression of functional constipation-related intestinal factors in the colon, characterized by a decrease in the expression of water channel proteins AQP3 and AQP4, as well as an increase in the expression of tight-junction proteins ZO-1, Claudin-1 and Occludin. Furthermore, L-Arabinose modulated the levels of hormones (MTL, Gas) and neurotransmitters (5-HT, VIP) related to the digestive systems of mice with constipation, resulting in elevated levels of 5-HT, MTL, and Gas and decreasing levels of VIP. Histopathological analysis also revealed that L-Arabinose intervention improved the intestinal inflammatory response. Furthermore, 16S rRNA sequencing and metabolomics of the intestinal microbiota demonstrated that L-Arabinose treatment improved both the intestinal microbiota composition and the metabolite levels. This study suggests that L-Arabinose can serve as a potential functional ingredient to promote intestinal health, enhance gastrointestinal motility and barrier function, regulate osmotic pressure, restore neurotransmitter levels, and effectively relieve functional constipation.

Sakuranetin, a flavonoid phytoalexin, has demonstrated neuroprotective properties and exhibits tyrosinase inhibitory activities, making it highly valuable in the cosmetics and pharmaceutical industries. In this study, we engineered a Yarrowia lipolytica strain for the high-titer de novo production of sakuranetin using glucose as a substrate. To effectively enhance sakuranetin production, we implemented a multimodule engineering strategy that included optimizing the sakuranetin synthesis pathway, designing a regeneration system for the methyl donor S-adenosyl methionine, increasing the malonyl-CoA precursor supplement, and constructing the feedback inhibition-relieved shikimate pathway. Moreover, a transcriptomic analysis was conducted to identify potential targets for further improving sakuranetin synthesis. As a result, the titer of de novo synthesized sakuranetin reached 344.0 mg/L from glucose in a 5 L bioreactor. These achievements hold significant promise for the sustainable and large-scale production of sakuranetin through industrial biomanufacturing.