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Milk powder, Polygonatum kingianum paste and sucrose were used as the main ingredients and a P. kingianum yogurt was fermented and developed. The optimal formula of P. kingianum yogurt was optimized by sensory evaluation, single-factor combined with response surface test. In addition, yoghurt was prepared with the optimised formula to compare the physicochemical and microbiological indices and antioxidant capacity of P. kingianum yoghurt with that of plain yoghurt (without P. kingianum). The results showed that the optimal formula for P. kingianum yoghurt was 1.5% addition of P. kingianum paste, 10% addition of sucrose and 0.02% addition of starter culture. P. kingianum yogurt had a delicate taste, with a moderate ratio of sweet and sour, with a light flavor of P. kingianum and sensory score of 87.62. All physicochemical and microbiological indexes met the national standards. The antioxidant capacity and texture analysis showed that compared with plain yoghurt, the addition of P. kingianum paste significantly improved the antioxidant capacity and stability of the yoghurt. Microstructural analysis showed that P. kingianum paste was tightly bound to milk protein, forming a densely structured milk gel and improving the viscosity value of yogurt. Therefore, a functional yogurt was developed by compounding P. kingianum, which had a certain market value.

Remote sensing estimation of maize residue cover (MRC) can rapidly acquire large-scale data on MRC, crucial for monitoring and promoting conservation tillage. Herein, seven tillage indices derived from Sentinel-2 satellite imagery were analyzed alongside measured MRC data to assess their correlation with MRC. MRC estimation models were built using six machine learning algorithms, including back propagation neural network (BPNN), random forest (RF), support vector regression (SVR), extreme gradient boosting (XGBoost), Stacking1, and Stacking2. Model performance was compared using the coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE). The potential for conservation tillage was explored. The results showed that the R2 values of the seven tillage indices in the study area exceeded 0.5, with particularly high correlations for NDTI and STI, with R2 values of 0.755 and 0.751, respectively. When using machine learning algorithms to construct models, the Stacking2 model exhibited the highest estimation accuracy, with an R2 of 0.923, RMSE of 3.32%, and MAE of 0.025, while Stacking1 also demonstrated robust performance, with an R2 of 0.910, RMSE of 3.45%, and MAE of 0.029. Among the base models, XGBoost achieved the highest estimation performance and the lowest error, with R2, RMSE, and MAE values of 0.884, 4.77%, and 0.031, respectively. The R2 values of RF, SVR, and BPNN were 0.865, 0.859, and 0.842, respectively, with RMSE values of 4.06%, 4.76%, and 5.91%, and MAE values of 0.039, 0.047, and 0.059, respectively. These results indicate that the Stacking2 model demonstrates a significant advantage in prediction accuracy. Geostatistical analysis of the inversion results of the Stacking2 model revealed that the proportions of farmland with MRC values exceeding 30% in Changchun, Songyuan, and Siping were 81.90%, 77.96%, and 83.58%, respectively. This indicates that Changchun and Siping have greater potential for implementing conservation tillage. This study demonstrates that the stacking ensemble learning model significantly improves the predictive performance by leveraging the strengths of multiple base models and accurately monitoring the spatial distribution of MRC.

IntroductionCarbohydrates, which make up 20 to 25% of tea beverages, are responsible for their flavor and bioactivity. Carbohydrates of pu-erh tea change during microbial fermentation and require further research. In this study, we examined the carbohydrate metabolism and expression of carbohydrate-active enzyme genes during the fermentation of tea leaves with Aspergillus luchuensis.MethodsWidely targeted metabolomics analysis, high-performance anion-exchange chromatography measurements, and transcriptomics were used in this study.ResultsAfter fermentation, the levels of soluble sugar, hemicellulose, lignin, eight monosaccharides, and seven sugar alcohols increased. Meanwhile, the relative contents of polysaccharides, D-sorbitol, D-glucose, and cellulose decreased. High expression of 40 genes encoding 16 carbohydrate enzymes was observed during fermentation (FPKM>10). These genes encode L-iditol 2-dehydrogenase, pectinesterase, polygalacturonase, α-amylase, glucoamylase, endoglucanase, β-glucosidase, β-galactosidase, α-galactosidase, α-glucosidase, and glucose-6-phosphate isomerase, among others.DiscussionThese enzymes are known to break down polysaccharides and cell wall cellulose, increasing the content of monosaccharides and soluble sugars.

Polygonatum kingianum Coll. et (Hemsl) is a famous Chinese traditional food and medicine analogous plant. The rhizome of P. kingianum showed a decrease in levels of alkaloids, amino acids and derivatives, terpenoids, and an increase in organic acid and saccharides when it was processed by the traditional method of “Nine Cycles of Steaming and Sun-Drying”. The relative content of 341 metabolites were increased (fold change, FC > 2; variable importance in projection, VIP > 1 and P-value, P 1, and P

The improvement of saline-alkali land plays a key role in ensuring food security and promoting agricultural development. Saline soils modifies the response of the soil microbial community, but research is still limited. The effects of applying phosphogypsum with rice cultivation (PRC) on soil physicochemical properties and bacterial community in soda saline-alkali paddy fields in Songnen Plain, China were studied. The results showed that the PRC significantly improved the physicochemical properties of soil, significantly reduced the salinity, increased the utilization efficiency of carbon, nitrogen, and phosphorus, and significantly increased the activities of urease and phosphatase. The activities of urease and phosphatase were significantly correlated with the contents of total organic carbon and total carbon. A redundancy analysis showed that pH, AP, ESP, HCO3−, and Na+ were dominant factors in determining the bacterial community structure. The results showed that PRC could improve soil quality and enhance the ecosystem functionality of soda saline-alkali paddy fields by increasing nutrient content, stimulating soil enzyme activity, and regulating bacterial community improvement. After many years of PRC, the soda-alkali soil paddy field still develops continuously and healthily, which will provide a new idea for sustainable land use management and agricultural development.

The management of crop residues in farmland is crucial for increasing soil organic matter and reducing soil erosion. Identifying the regional extent of crop residue cover (CRC) is vital for implementing conservation tillage and formulating agricultural subsidy policies. The Google Earth Engine (GEE) and remote sensing images from 2019 to 2023 were used to obtain spectral characteristics before the maize seedling stage in Northeast China, followed by constructing the CRC estimation models using machine learning algorithms. To avoid the impact of multicollinearity among data, three machine learning algorithms—ridge regression (RR), partial least squares regression (PLSR), and least absolute shrinkage and selection operator (LASSO)—were employed. By comparing the accuracy of these methods, the most accurate model was determined and applied to subsequent CRC estimation. Based on the estimated CRC and Conservation Technology Information Center definitions of tillage practices, the conservation tillage mapping was completed, and the spatiotemporal distribution characteristics were thoroughly analyzed. The following findings were demonstrated: (1) the PLSR-based model outperformed RR (Pearson’s correlation coefficient (r) = 0.8875, R2 = 0.7877, RMSE = 6.99%) and LASSO (r = 0.8903, R2 = 0.7926, RMSE = 6.88%) with higher accuracy (r = 0.9264, R2 = 0.8582, RMSE = 4.93%). (2) Over the five years, the average no-tillage (NT) proportion in the study area was 15.9%, reduced tillage (RT) was 17.8%, and conventional tillage (CT) was 66.3%. In 2020 and 2022, NT rates were significantly higher at 27.5% and 15.5%, while RT were 15.7% and 30.0%, respectively. (3) Compared to the Sanjiang and Liaohe Plains (RT = 1907 km2 and 1336 km2, and NT = 559 km2 and 585 km2, respectively), the Songnen Plain exhibited higher conservation tillage rates (where RT was 3791 km2 and NT was 1265 km2). This provides crucial scientific evidence for the management and planning of conservation tillage, thereby optimizing farmland production planning, enhancing production efficiency, and promoting the development of sustainable agricultural production systems.

Abstract Increasing evidences demonstrate that chlorogenic acid (CGA), a polyphenol with multiple effects such as anti-inflammatory and anti-oxidation, protects against myocardial ischemia–reperfusion injury (MIRI) in vitro and in vivo. But its detailed cardiac protection mechanism is still unclear. The MIRI mice model was established by ligating the left anterior descending branch (LAD) of the left coronary artery in C57BL/6 mice. Sixty C57BL/6 mice were randomly divided into four groups. CGA group and CGA + I/R group (each group n = 15) were gavaged with 30 mg/kg/day CGA for 4 weeks. Sham group and I/R group mice (each group n = 15) were administered equal volumes of saline. In vitro MIRI model was constructed by hypoxia and reoxygenation of HL-1 cardiomyocytes. The results showed that CGA pretreatment reduced myocardial infarction size and cTnT contents in serum, simultaneously reduced the levels of Lnc Neat1 expression and attenuated NLRP3 inflammasome-mediated pyroptosis in myocardial tissue. Consistent with in vivo results, the pretreatment of 0.2 μM and 2 μM CGA for 12 h in HL-1 cardiomyocytes depressed hypoxia/reoxygenation-induced Lnc Neat1 expression, NLRP3 inflammasome activation and pyroptosis. Lnc Neat1 shRNA transfection mediated by lentivirus in HL-1 cardiomyocytes significantly reduced activation of NLRP3 inflammasome and pyroptosis. Our findings suggest that CGA protects against MIRI by depressing Lnc Neat1 expression and NLRP3 inflammasome-mediated pyrotosis. Inhibiting the levels of Lnc Neat1 expression may be a therapeutic strategy for MIRI.

Alkaline stress with high pH levels could significantly influence plant growth and survival. The enzyme 9-cis-epoxycarotenoid dioxygenase (NCED) serves as a critical bottleneck in the biosynthesis of abscisic acid (ABA), making it essential for regulating stress tolerance. Here, we show that OsNCED3-overexpressing rice lines have increased ABA content by up to 50.90% and improved transcription levels of numerous genes involved in stress responses that significantly enhance seedling survival rates. Overexpression of OsNCED3 increased the dry weight contents of the total chlorophyll, proline, soluble sugar, starch, and the activities of antioxidant enzymes of rice seedlings, while reducing the contents of O2·−, H2O2, and malondialdehyde under hydroponic alkaline stress conditions simulated by 10, 15, and 20 mmol L−1 of Na2CO3. Additionally, the OsNCED3-overexpressing rice lines exhibited a notable increase in the expression of OsNCED3; ABA response-related genes OsSalT and OsWsi18; ion homeostasis-related genes OsAKT1, OsHKT1;5, OsSOS1, and OsNHX5; and ROS scavenging-related genes OsCu/Zn-SOD, OsFe-SOD, OsPOX1, OsCATA, OsCATB, and OsAPX1 in rice seedling leaves. The results of these findings suggest that overexpression of OsNCED3 upregulates endogenous ABA levels and the expression of stress response genes, which represents an innovative molecular approach for enhancing the alkaline tolerance of rice seedlings.

Saline–alkaline (SA) stress is characterized by high salinity and high alkalinity (high pH), which severely inhibit plant growth and cause huge losses in crop yields worldwide. Here we show that a moderate elevation of endogenous abscisic acid (ABA) levels by RNAi-mediated suppression of OsABA8ox1 (OsABA8ox1-kd), a key ABA catabolic gene, significantly increased tolerance to SA stress in rice plants. We produced OsABA8ox1-kd lines in two different japonica cultivars, Dongdao 4 and Nipponbare. Compared with non-transgenic control plants (WT), the OsABA8ox1-kd seedlings accumulated 25.9%–55.7% higher levels of endogenous ABA and exhibited reduced plasmalemma injury, ROS accumulation and Na+/K+ ratio, and higher survival rates, under hydroponic alkaline conditions simulated by 10, 15, and 20 mmol L−1 of Na2CO3. In pot trials using SA field soils of different alkali levels (pH 7.59, 8.86, and 9.29), OsABA8ox1–kd plants showed markedly higher seedling survival rates and more vigorous plant growth, resulting in significantly higher yield components including panicle number (85.7%–128.6%), spikelets per panicle (36.9%–61.9%), branches (153.9%–236.7%), 1000–kernel weight (20.0%–28.6%), and percentage of filled spikelets (96.6%–1340.8%) at harvest time. Under severe SA soil conditions (pH = 9.29, EC = 834.4 μS cm−1), OsABA8ox1-kd lines showed an 194.5%–1090.8% increase in grain yield per plant relative to WT plants. These results suggest that suppression of OsABA8ox1 to increase endogenous ABA levels provides a new molecular approach for improving rice yield in SA paddies.

Electrical conductivity (EC) is an important index of soil salinity level and an essential factor in judging whether improvement can be made and assessing the improvement, if any. However, saline soils of different types show different spectral characteristic bands, which affects the retrieval precision to a certain extent. To tackle this issue, we present a novel way of modeling. Specifically, we compare the correlation of sensitive bands, multiplication of sensitive bands, and spectral indexes with EC data to determine the optimal input parameters, and take the EC data after Box-Cox transformation as the output. We then try out several machine-learning algorithms to establish retrieval models for soil EC. Validation results show that the model precision increases by 3.23–85.71% after EC data transformation and machine learning models produce 29.41–86.67% higher precision than the linear regression model. Finally, using the optimal model, we retrieve pixel-level (10 m × 10 m) EC for the soil in our study areas. This provides necessary data support for working out soil desalinization initiatives and evaluating the effectiveness of such initiatives.

IntroductionRadix Notoginseng, one of the most famous Chinese traditional medicines, is the dried root of Panax notoginseng (Araliaceae). Stems and leaves of P. notoginseng (SLPN) are rich in secondary metabolites and nutrients, and authorized as a food resource, however, its utilization needs further research.MethodsA SLPN-instant beverage was manufactured from SLPN through optimization by response surface design with 21-fold of 48.50% ethanol for 39 h, and this extraction was repeated twice; the extraction solution was concentrated to 1/3 volume using a vacuum rotatory evaporator at 45°C, and then spray dried at 110°C. Nutritional components including 14 amino acids, ten mineral elements, 15 vitamins were detected in the SLPN-instant beverage; forty-three triterpenoid saponins, e.g., ginsenoside La, ginsenoside Rb3, notoginsenoside R1, and two flavonoid glycosides, as well as dencichine were identified by UPLC-MS.ResultsThe extraction rate of SLPN-instant beverage was 37.89 ± 0.02%. The majority nutrients were Gly (2.10 ± 0.63 mg/g), His (1.23 ± 0.07 mg/g), α-VE (18.89 ± 1.87 μg/g), β-VE (17.53 ± 1.98 μg/g), potassium (49.26 ± 2.70 mg/g), calcium (6.73 ± 0.27 mg/g). The total saponin of the SLPN-instant beverage was 403.05 ± 34.98 mg/g, majority was notoginsenoside Fd and with contents of 227 ± 2.02 mg/g. In addition, catechin and γ-aminobutyric acid were detected with levels of 24.57 ± 0.21 mg/g and 7.50 ± 1.85 mg/g, respectively. The SLPN-instant beverage showed good antioxidant activities with half maximal inhibitory concentration (IC50) for scavenging hydroxyl (OH–) radicals, superoxide anion (O2–) radicals, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS+) radicals were 0.1954, 0.2314, 0.4083, and 0.3874 mg/mL, respectively.ConclusionWe optimized an analytical method for in depth analysis of the newly authorized food resource SLPN. Together, an instant beverage with antioxidant activity, rich in nutrients and secondary metabolites, was manufactured from SLPN, which may improve the utilization of SLPN.

The plant hormone abscisic acid (ABA) regulates the plant response to environmental stress; therefore, ABA priming is an effective strategy for enhancing stress tolerance in rice. In this study, we investigated the priming effects of 1 and 5 µM ABA on the biochemical and physiological traits associated with seedling growth performance in two rice cultivars exposed to saline (100 mM NaCl) and alkaline (15 mM Na2CO3) stress via root drenching. ABA pretreatment effectively reduced damage in rice seedlings by mitigating the increases in Na+/K+ ratio, membrane injury, contents of Na+, malondialdehyde, hydrogen peroxide, and superoxide anion radical, and prevented reductions in K+ and total chlorophyll contents, and ROS-related enzyme activities in both cultivars under saline and alkaline stresses. Rice seedlings with ABA pretreatment under alkaline stress had a stronger ability to maintain ion homeostasis, eliminate ROS, and induce changes in endogenous ABA levels via the upregulation of OsHKT1;5, OsSOS1, OsNHX5, OsPOX1, OsCATA, OsNCED3, OsSalT, and OsWsi18 and downregulation of OsRbohA than under saline stress. The saline–alkaline (SA)-sensitive cultivar demonstrated greater sensitivity to the priming effect of ABA than that of the SA-tolerant cultivar under both stress conditions. These findings have implications for rice adaptation to SA soils.

Modifying saline–alkali soil is crucial for ensuring food security and expanding arable land. Microorganisms play a key role in driving various biochemical processes in agricultural ecosystems. However, limited information exists on the changes in the microbial community and soil structure in soda saline-alkali soil under modified conditions. In this study, we examined the changes in soil physicochemical properties of saline–alkali soil altered by rice planting alone and by combined application of phosphogypsum in the Songnen Plain. The results demonstrated that phosphogypsum significantly improved the soil’s physicochemical properties; it notably reduced salinity and alkalinity while enhancing nutrient structure. Additionally, the utilization efficiency of carbon (C), nitrogen (N), and phosphorus (P) increased. Fungal community diversity also significantly improved, influenced mainly by soil water content (SWC), total organic carbon (TOC), soil organic matter (SOM), total nitrogen (TN) and sodium ion (Na+). TOC, SOM, TN, ESP, and Na+ served as the primary drivers affecting the fungal community. Our findings indicate that combining rice planting with phosphogypsum application effectively modifies saline–alkali soil, regulates fungal community structure, and enhances long-term soil health. Furthermore, the beneficial effects of phosphogypsum on saline–alkali soil persist for persists for several years, largely owing to its role in promoting microbial community growth.

Soybean (Glycine max) is the main oilseed crop that provides vegetable oil for human nutrition. The main objective of its breeding research is to increase the total oil content. In the Kennedy pathway, Diacylglycerol acyltransferase (DGAT) is a rate-limiting enzyme that converts diacylglycerol (DAG) to triacylglycerol (TAG). Here, the AhDGAT3 gene was cloned from peanut and overexpressed in the wild-type (WT) Arabidopsis. The total fatty acid content in T3AhDGAT3 transgenic Arabidopsis seeds was 1.1 times higher on average than that of the WT. Therefore, AhDGAT3 was transferred into the WT (JACK), and four T3 transgenic soybean lines were obtained, which proved to be positive using molecular biological detection. Specific T-DNA insertion region location information was also obtained via genome re-sequencing. The results of high-performance gas chromatography showed that the contents of oleic acid (18:1) composition and total fatty acids in transgenic soybean plants were significantly higher than that of the WT. However, linoleic acid (18:2) was much lower compared to the WT. The agronomic trait survey showed that the quantitative and yield traits of AhDGAT3 transgenic soybean were better than those of the WT. These results suggest that fatty acids in transgenic soybeans, especially oleic acid and total fatty acid, are enhanced by the over-expression of AhDGAT3.

Tea tree [Camellia sinensis var. sinensis or assamica (L.) O. Kuntze], an important crop worldwide, is usually pruned to heights of 70 to 80 cm, forming pruned tea tree (PTT) plantations. Currently, PTTs are transformed into unpruned tea tree (UPTT) plantations in Yunnan, China. This has improved the quality of tea products, but the underlying reasons have not been evaluated scientifically. Here, 12 samples of sun-dried green teas were manufactured using fresh leaves from an UPTT and the corresponding PTT. Using sensory evaluation, it was found that the change reduced the bitterness and astringency, while increasing sweetness and umami. Using high performance liquid chromatography detection showed that the contents of free amino acids (theanine, histidine, isoleucine and phenylalanine) and catechin gallate increased significantly (P < 0.05), whereas the content of alanine decreased significantly (P < 0.05). A liquid chromatography–mass spectrometry-based metabolomics analysis showed that the transformation to UPTT significantly decreased the relative levels of the majority of flavonols and tannins (P < 0.05), as well as γ-aminobutyric acid, caffeine and catechin (epigallocatechin, catechin, epigallocatechin gallate, gallocatechin gallate), while it significantly increased the relative contents of catechins (gallocatechin, epicatechin, epicatechin gallate and catechin gallate), phenolic acids and some amino acids (serine, oxidized glutathione, histidine, aspartic acid, glutamine, lysine, tryptophan, tyramine, pipecolic acid, and theanine) (P < 0.05). In summary, after transforming to UPTT, levels of amino acids, such as theanine increased significantly (P < 0.05), which enhanced the umami and sweetness of tea infusions, while the flavonoids (such as kaempferol, myricetin and glycosylated quercetin), and caffeine contents decreased significantly (P < 0.05), resulting in a reduction in the bitterness and astringency of tea infusions and an increase in tea quality.

Building information modeling (BIM) is a crucial information technology that promotes the transformation and upgrading of the construction industry. It has been widely used in various stages of construction projects, including design, construction, and operation. However, BIM technology still faces numerous obstacles in practice. From the perspective of construction practitioners, this study constructs a structural equation model to explore the obstacles encountered by construction practitioners in the process of applying BIM technology. Task–technology fit, effort expectancy, performance expectancy, user trust, and facilitating conditions can significantly improve practitioners’ behavioral intention, with task–technology fit having the most significant impact on behavioral intention. Facilitating conditions and behavioral intention significantly affect usage behavior, while perceived cost does not significantly affect behavioral intention. The multiple-group analysis found that in the path of performance expectancy on behavioral intention, males have a significant effect while females do not; in the path of facilitating conditions on behavioral intention, higher education levels have a significant effect while lower education levels do not; in the path of facilitating conditions on behavioral behavior, lower usage time has a significant effect while higher usage time does not. Suggestions for promoting the application of BIM technology are proposed in this article to improve its utilization rate. This study provides more perspectives and ideas for future research on BIM diffusion.

We aimed to determine the optimal combination of amendments to increase rice yields in saline-sodic soil. The effects of different proportions of phosphogypsum (P), farmyard fertilizer (F), and wood peat (W) across the main growth period of rice were studied. A total of 14 treatments were designed based on the “3414” fertilizer effect field experiment scheme, with 3 factors (P, F, and W) and 4 application levels per factor. Application of a combination of P, F, and W reduced soil pH and electrical conductance (EC) (p < 0.05), increasing rice yields. The theoretical rice yield after treatment P2F2W2 (P 30, F 50, and W 30 t·ha−1) was 5819.20 kg·ha−1, which was 32.52-fold higher than that after P0F0W0 (P, F, and W, 0 t·ha−1). Panicle weight, number of total filled grains, total grain weight, and seed-setting rate were 9.76, 17.35, 32.11, and 3.96 times higher than those in the control treatment, respectively. Compared with the control P0F0W0 treatment, soil pH in P2F2W2 in 0–5, 5–10, 10–15, and 15–20 cm depth decreased by 12.69, 12.32, 11.18, and 10.70%, respectively, and soil EC was 1.06-fold, and 70.79, 49.30, and 47.76% higher, respectively. Overall, we found that the P2F2W2 treatment, with a combination of P, 29.09–32.38 t·ha−1; F, 40.36–46.97 t·ha−1; and W, 19.57–23.95 t·ha−1 was optimal in this experiment.

Alcoholic fatty liver disease (AFLD) is caused by long-term heavy alcohol consumption; therefore, useful and practical methods for the prevention of AFLD are urgently needed. The edible flower of Dendrobium officinale contains diverse flavonoids, and has shown antioxidant activity as well as antihypertensive and anti-inflammatory effects. In this study, an AFLD model was established, the protective effect of D. officinale flower (DOF) ethanol extract on AFLD was evaluated, and its mechanisms were investigated by analyzing gut microbiota and short-chain fatty acids (SCFAs). DOF extract (DOFE) supplementation promoted alcohol metabolism, restored hepatic antioxidant capacity, alleviated oxidative stress, reduced inflammatory factor levels, and inhibited dyslipidemia induced by alcohol intake in chronic alcohol-exposed mice, especially in the high DOFE group. Moreover, DOFE supplementation increased the diversity, structure, and composition of the gut microbiota in mice, restored some of the abnormal SCFA levels caused by AFLD, and helped restore intestinal function. DOFE supplementation significantly increased the relative abundance of Akkermansia, suggesting that Akkermansia may be a potential target of the protective effect of DOFE. Therefore, DOFE supplementation to improve the composition of the gut microbiota may be an effective therapeutic strategy for the prevention of AFLD.

Tea polyphenol (TPs) oxidation caused by polyphenol oxidase (PPO) in manufacturing is responsible for the sensory characteristics and health function of fermented tea, therefore, this subject is rich in scientific and commercial interests. In this work, an in vitro catalysis of TPs in liquid nitrogen grinding of sun-dried green tea leaves by PPO was developed, and the changes in metabolites were analyzed by metabolomics. A total of 441 metabolites were identified in the catalyzed tea powder and control check samples, which were classified into 11 classes, including flavonoids (125 metabolites), phenolic acids (67 metabolites), and lipids (55 metabolites). The relative levels of 28 metabolites after catalysis were decreased significantly (variable importance in projection (VIP) > 1.0, p < 0.05, and fold change (FC) < 0.5)), while the relative levels of 45 metabolites, including theaflavin, theaflavin-3′-gallate, theaflavin-3-gallate, and theaflavin 3,3′-digallate were increased significantly (VIP > 1.0, p < 0.05, and FC > 2). The increase in theaflavins was associated with the polymerization of catechins catalyzed by PPO. This work provided an in vitro method for the study of the catalysis of enzymes in tea leaves.

With the continuous increase in saline–alkali land, sustainable development of the global environment and ecology have been seriously affected. This study compared the absorption and accumulation patterns of 11 elements in different parts (roots, stems and leaves) of different leaf Na regulation strategies of the pioneer plant Chenopodiaceae in saline–alkali land and evaluated the effects of soil nutrient status and soil salinity on the distribution of plant elements. The results showed that the changes in the content of Ca, Mg and Na in plants are affected by the salt-tolerant type and on different parts. Soil salinity had no significant effect on element concentrations in different parts of plants. The Pearson correlation coefficient showed that the correlation between plants and soil elements was different, and different parts of plants had the characteristics of selective absorption of soil elements. The salt tolerance type and soil mineral element concentrations explained most of the variation observed in element concentrations in Chenopodiaceae plants; the soil salinity property played only a minor role. It was concluded that the genetic factors are the prerequisite in the composition pattern of leaf elements in Chenopodiaceae, and soil factors are the key to determining element accumulation. These conclusions provide an effective reference for evaluating plant breeding and its response to environmental change in saline–alkali arid areas in Hulunbuir grassland and other parts of the world.

Application of sand can ameliorate rice paddy fields converted from saline–sodic land. However, the requirement of huge amount of sand has been limiting its practical application. In this study, flushing during saline sodic-sensitive stages of rice plant growth was incorporated into the ameliorating system to reduce the sand usage. A split-plot design was adopted with sand application (SA) with two levels as main plots and flushing during the sensitive stages (FL) with two levels as subplots in a hard saline–sodic soil, Northeast China. Four treatments included CK (no-sand, no-flush flooding), NF (non-sand, flush flooding), SN (sand, no-flush flooding), and SF (sand, flush flooding). The results showed that both SA and FL significantly affected all the investigated yield parameters. The combined effect of SA and FL on the grain yield was additive in the first year in respect of the effect on panicle density and seed weight per panicle; while it showed synergistic effect on the seed weight per panicle and grain yield in the second year. The rice yield in different treatments was in the order of SF > SN > NF > CK in both years, with the highest yield (4.37 t ha−1) obtained by SF treatment in the second year. Our results demonstrate that half the traditional amount of sand in combination with water-flushing during the saline–sodic-sensitive growth stages of rice is sufficiently effective in ameliorating saline–sodic soil and thereby enhancing rice grain yield in saline–sodic paddy fields.

The spectral features of soils are a comprehensive representation of their physicochemical parameters, surface states, and internal structures. To date, spectral measurements have been mostly performed for powdered soils and smooth aggregate soils, but rarely for cracked soils; a common state of soda-saline soils. In this study, we measured the spectral features of 57 saline soil samples in powdered, aggregate, and cracked states for comparison. We then explored in depth the factors governing soil spectral features to build up simple and multiple linear regression models between the spectral features and physicochemical parameters (salt content, Na+, pH, and electronic conductivity (EC)) of saline soils in different states. We randomly selected 40 samples to construct the models, and used the remaining 17 samples for validation. Our results indicated that the regression models worked more effectively in predicting physicochemical parameters for cracked soils than for other soils. Subsequently, the crack ratio (CR) was introduced into the regression models to modify the spectra of soils in powdered and aggregate states. The accuracy of prediction was improved, evidenced by a 2⁻11% decrease in the parameters mean absolute error (MAE).

BackgroundManagement regimes for vegetation restoration of degraded grasslands can significantly affect the process of ecological succession. However, few studies have focused on variation in the soil seed bank during vegetation restoration under different management regimes, especially in saline-alkaline grassland habitats. Our aim was to provide insights into the ecological effects of grassland management regimes on soil seed bank composition and vegetation establishment in mown, fenced, transplanted and natural grassland sites, all dominated by the perennial rhizomatous grass Leymus chinensis.MethodologyWe studied species composition and diversity in both the soil seed bank and aboveground vegetation in differently managed grasslands in Northeast China. An NMDS (nonmetric multidimensional scaling) was used to evaluate the relationship between species composition, soil seed banks, aboveground vegetation and soil properties.Principal findingsFenced and mown grassland sites had high density and species richness in both the soil seed bank and aboveground vegetation. The Transplanted treatment exhibited the highest vegetation growth and seed production of the target species L. chinensis. Seeds of L. chinensis in the soil occurred only in transplanted and natural grassland. Based on the NMDS analysis, the number of species in both the soil seed bank and aboveground vegetation were significantly related to soil Na+, Cl-, RSC (residual sodium carbonate), alkalinity, ESP (exchangeable sodium percentage) and AP (available phosphorus).ConclusionsSoil seed bank composition and diversity in the saline-alkaline grassland were significantly affected by the management regimes implemented, and were also significantly related to the aboveground vegetation and several soil properties. Based on vegetative growth, reproductive output and maintenance of soil seed bank, the transplanting was identified as the most effective method for relatively rapid restoration of the target species L. chinensis. This approach could be beneficial for the restoration of dominant species in a wide range of degraded grassland ecosystems.

In order to broaden the application field of proanthocyanidins (PCs) from Zijuan tea, it is necessary to establish an environmental and economic extraction method of PCs from Zijuan tea. Based on the single‐factor experiment, Box‐Behnken response surface methodology was used to study the effects of solid–liquid ratio, the concentration of citric acid solution, ultrasonic power, ultrasonic time, and ultrasonic temperature on the yield of PCs from Zijuan tea. The results showed that the optimum extraction conditions were as follows: 1:35.3 (m/V) solid–liquid ratio, 0.08% citric acid solution, 233.0 W ultrasonic power, 64.0°C ultrasonic temperature, and 48.6 min ultrasonic time. Under these conditions, the yield of PCs was 5.18 ± 0.13 mg/g. Meanwhile, the half inhibitory concentration (IC50) of PCs on 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) and hydroxyl radical (·OH) were 0.5417 and 0.4825 mg/mL, respectively; antimicrobial activity of PCs on several strains tested showed antimicrobial effect as follows: Bacillus subtilis >Staphylococcusaureus >Escherichiacoli >Saccharomycescerevisiae. Therefore, the results provided a theoretical basis for the application of PCs in food development. Novelty impact statement: The extraction conditions significantly affected the yield of proanthocyanidins (PCs) from Zijuan tea. While Zijuan tea extracted with 0.08% the citric acid solution (1:35.3 [m/V] solid–liquid ratio) and ultrasonic instrument (233.0 W ultrasonic power, 64.0°C ultrasonic temperature, and 48.6 min ultrasonic time) could be used as a potential food additive, exhibiting a promising antioxidant potential for food product applications. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the effects of different fertilizer types and application rates on ammonia volatilization loss and to explore nitrogen distribution and nitrogen use efficiency using the 15N isotope tracing technique in different alkaline salt-affected conditions in the Songnen Plain, Northeast China. The results showed a decreasing trend in ammonia volatilization loss from ammonium nitrate and ammonium sulfate, but not that from urea, as the electrical conductivity gradient increased, whereas the reverse trend was found as the pH gradient increased. Ammonia volatilization loss increased in moderately salt-affected soil compared with that in slightly salt-affected soil, particularly during the tillering stage, regardless of the N fertilizer rate. The percentage of N absorbed by rice plants increased from urea but decreased from the soil as the amount of nitrogen was increased. Interestingly, the N retention rate in soil decreased and rice grain yield and nitrogen agronomic efficiency increased as the amount of nitrogen increased in both salt-affected soil conditions. The nitrogen application amount of highest N physiological efficiency was 225 kg.N/ha. Considering high rice production and a minimal environmental threat, we should fully consider controlling ammonia volatilization losses by adjusting the fertilizer type and the crop stage when the fertilizer is applied. [ABSTRACT FROM AUTHOR]

Leymus chinensis (Trin.) Tzvel. (Poaceae) is a dominant plant in the western Songnen Plain of northeastern China. Soil saliniza-tion, N deficiency, and current management practices have resulted in grassland degradation in the region. The objective of this study was to investigate the effect of N application onL. chinensis. A 3-yr field experiment was conducted in two nearby fields at the Da'an Sodic Land Experiment Station (DASLES) from 2009 to 2011. Both fields were classified as moderate saline-sodic grassland (MSSL) and severe saline-sodic grassland (SSSL), respectively. Nitrogen application rates were 0 (no fertilizer as control), 30, 60, 90, 120, 150, 180, and 210 kg N ha-1. Nitrogen application improved herbage yield from 2.0 t ha-1 without N to more than 10.7 t ha-1 with 180 kg ha-1 N in MSSL, and from 1.0 t ha-1 without N to 4.9 t ha-1 with 180 kg ha-1 N in SSSL, herbage yields increased 5.4 and 4.9 times in MSSL and SSSL, respectively. Nitrogen use efficiency (NUE) was generally higher in MSSL than that in SSSL, the highest values of average NUE were the treatments with 120 kg N ha-1 in MSSL and 150 kg N ha-1 in SSSL based on the results of regression analysis. Our overall results support N applications of 90 to 120 kg N ha-1 in MSSL and 120 to 150 kg N ha-1 in SSSL. Nitrogen application can improve L. chinensis yield, and prevent grassland degradation in the region. [ABSTRACT FROM AUTHOR]

Aims Leymus chinensis is an original dominant plant in the Songnen grassland, and it has great value for restoration of severely degraded land. However, seeds are dormant, and low germination percentage is a problem for restoring L.chinensis grassland. The mechanism of seed dormancy is not been well understood. The primary aims of the present study were to investigate the dormancy mechanism of L.chinensis seeds (caryopses) with reference to the role of embryo-covering layers, endogenous hormones and temperature. Methods Changes in concentration of the endogenous hormones GA3, indoleacetic acid (IAA), zeatin riboside (ZR) and abscisic acid (ABA) in L.chinensis seeds from anthesis to maturity were measured by the enzyme-linked immunosorbent assay method. Germination at different stages of maturity were tested at 16/28°C, 5/28°C and 5/35°C for intact seeds with glumes (control), intact seeds with glumes removed (naked-whole seeds) and intact seeds with glumes and one-half of the endosperm removed (naked-half seeds). Important Findings Of the four endogenous hormones monitored, only the concentration of ZR differed significantly between the beginning and the end of seed development (increased); the GA3/ABA ratio also did not differ. Rank of germination percentage of control at the three temperature regimens was 5/28°C > 16/28°C > 5/35°C. Germination percentage of the naked-half seeds reached 100% under the three temperature regimens. We concluded that dormancy of L.chinensis seeds is not mainly controlled by endogenous hormones. Germination temperature, mechanical resistance of glumes and inhibition of endosperm are the main factors controlling dormancy and germination of L.chinensis seeds. [ABSTRACT FROM PUBLISHER]

Planting rice (OryzasativaL.) is an effective and feasible approach for improving salt-affected soils, especially in saline-sodic soils. Improved rice is the main biological measure for rapid treatment and utilization of a saline-sodic paddy field. Reasonable application of nitrogen fertilizer is an important measure for obtaining saline-sodic soil high yield. Dongdao 4 (D-4), Dongdao 2 (D-2), Changbai 9 (C-9), and Baijing 1 (B-1)) were studied by a field experiment in this paper. On the growth, yield, and yield component responses of different nitrogen levels (150 kg N/ha, 225 kg N/ha and 300 kg N/ha), and the nitrogen uptake of four saline-tolerant rice cultivars at different nitrogen application levels was calculated, which provided a useful reference for the rational application of nitrogen fertilizer in a salinesodic paddy field. The results showed that: biomass of four kinds of rice accumulates over time and reached their maximums in September, with the biomasses of D-2 and D-4 reaching the maximum of 225 kg N/ha, and C-9 and B-1 reaching the maximum at 300 kg N/ha, which is related to rice varieties; the yields of four salt-tolerant rice plants reached the highest in 150 kg N/ha; applied nitrogen fertilizer reasonably was beneficial to increase the number of spikes and the number of effective grains per spike, in this experiment, the optimum amount of nitrogen is 150 kg N/ha, and the number of spikes and the number of effective grains per spike also were major factors in increasing production. With 1000-grain weight, primary and secondary branches made no significant contribution to the yield; the N uptake of four kinds of rice gradually increased over time and reached the maximum in September. There was no significant difference in the nitrogen grain production efficiency of 4 rice varieties under different nitrogen application rates; with the increase of nitrogen application rate, partial productivity of nitrogen fertilizer nitrogen of 4 rice varieties all decreased. Therefore, reasonable application of nitrogen fertilizer promoted the uptake and transfer of nitrogen to the plant. [ABSTRACT FROM AUTHOR]