摘要：
Summer-autumn tea leaves are abundant, yet their utilization remains low. Our study enhances the quality and flavor of Golden Flower loose tea (GFLT) from fresh summer-autumn tea leaves by using a special "Golden Flower" fungus (strain ACF-2). The strain ACF-2, identified as Aspergillus cristatus with yellow cleistothecium and isolated from Fu Brick Tea, was characterized by colony morphology, microstructural analyses, and phylogenetic examination using a 3-gene dataset (BenA, CaM, RPB2). Inoculation of raw dark tea products with A. cristatus led to a significant increase in tea water extract and a reduction in tea polyphenols, soluble sugars, flavonoids, and total amino acids, thereby enhancing the quality and flavor of GFLT. HS-SPME-GC-MS analysis of GFLT aroma revealed that A. cristatus substantially improved the tea's aroma profile. 9 volatile compounds-(Z)-jasmone I, beta-cyclocitral, linalool oxide I, linalool, hexanal, 1-octen-3-ol, (Z)-citral, citral, and methyl salicylate, were found to be significantly elevated in GFLT compared to the controls. Our findings provide both theoretical and practical insights into optimizing the utilization of summer-autumn tea leaves, identifying the "Golden Flower" fungus, and understanding its impact on GFLT quality. In summary, fermenting A. cristatus to produce GFLT may be a new channel to utilize summer-autumn tea.
摘要：
Soil microbes regulate various biogeochemical cycles on Earth and respond rapidly to climate change, which is accompanied by changes in soil pH. However, the long-term patterns of these changes under future climate scenarios remain unclear. We propose a core-bacteria-forecast model (CoBacFM) to model soil pH changes by shifts of core bacterial groups under future scenarios using a curated soil microbiota dataset of global grasslands. Our model estimates that soil pH will increase in 63.8%–67.0% of grassland regions and decrease in 10.1%–12.4% of regions. Approximately 32.5%–32.9% of regions will become more alkaline by 5.6%, and these areas expand in all future scenarios. These results were supported by 14 warming simulation experiments. Using bacterial responses as bioindicators of soil pH, the CoBacFM method can accurately forecast pH changes in future scenarios, and the changing global climate is likely to result in the alkalization of grasslands.
摘要：
Bulb rot of lily ( Lilium brownii var. viridulum), ), caused by Fusarium commune, is a serious soilborne disease of lily plants. In this study, several bacterial isolates were obtained from the rhizosphere of healthy lily plants and evaluated for biocontrol potential. Among the obtained isolates, GX1 had the highest level of antifungal activity in vitro, inhibiting the growth of F. commune by 52.0 %, relative to the control (CK). The isolate was identified as Bacillus velezensis based on its morphology and 16S rRNA and gyrB gene sequence analysis. The fermentation broth of GX1 after 12 d of fermentation at 25 degrees C (pH 7) exhibited strong antifungal activity. A crude lipopeptide extracts of GX1 fermentation broth was as effective (50.3 %) at inhibiting the mycelial growth of F. commune as living cultures of GX1. GX1 possesses fenD, bmyB, srfAA and bacA antimicrobial peptide (AMP) genes, which may be the primary source of its antifungal activity. GX1 significantly reduced the disease severity index of lily bulb rot in pot experiments, indicating that B. velezensis GX1 has substantial potential for the biological control of lily bulb rot.
摘要：
Some pathogens colonize plant leaves, but others invade the roots, including the vasculature, causing severe disease symptoms. Plant innate immunity has been extensively studied in leaf pathosystems; however, the precise regulation of immunity against vascular pathogens remains largely unexplored. We previously demonstrated that loss of function of the receptor kinase FERONIA (FER) increases plant resistance to the typical vascular bacterial pathogen Ralstonia solanacearum. Here, we show that upon infection with R. solanacearum, root xylem cell walls in Arabidopsis thaliana become highly lignified. FER is specifically upregulated in the root xylem in response to R. solanacearum infection, and inhibits lignin biosynthesis and resistance to this pathogen. We determined that FER interacts with and phosphorylates the transcription factor RESPONSIVE TO DESICCATION 26 (RD26), leading to its degradation. Overexpression and knockout of RD26 demonstrated that it positively regulates plant resistance to R. solanacearum by directly activating the expression of lignin-related genes. Tissue-specific expression of RD26 in the root xylem confirmed its role in vascular immunity. We confirmed that the FER-RD26 module regulates lignin biosynthesis and resistance against R. solanacearum in tomato (Solanum lycopersicum). Taken together, our findings unveil that the FER-RD26 cascade governs plant immunity against R. solanacearum in vascular tissues by regulating lignin deposition. This cascade may represent a key defense mechanism against vascular pathogens in plants.
关键词：
CaAFR1;CaMYB61;Khib;cellulose and hemicellulose;histone deacetylases;stem lodging
摘要：
Plant stems constitute the most abundant renewable resource on earth. The function of lysine (K)-2-hydroxyisobutyrylation (K(hib)), a novel post-translational modification (PTM), has not yet been elucidated in plant stem development. Here, by assessing typical pepper genotypes with straight stem (SS) and prostrate stem (PS), we report the first large-scale proteomics analysis for protein K(hib) to date. K(hib)-modifications influenced central metabolic processes involved in stem development, such as glycolysis/gluconeogenesis and protein translation. The high K(hib) level regulated gene expression and protein accumulation associated with cell wall formation in the pepper stem. Specially, we found that CaMYB61 knockdown lines that exhibited prostrate stem phenotypes had high K(hib) levels. Most histone deacetylases (HDACs, e.g., switch-independent 3 associated polypeptide function related 1, AFR1) potentially function as the "erasing enzymes" involved in reversing K(hib) level. CaMYB61 positively regulated CaAFR1 expression to erase K(hib) and promote cellulose and hemicellulose accumulation in the stem. Therefore, we propose a bidirectional regulation hypothesis of "K(hib) modifications" and "K(hib) erasing" in stem development, and reveal a novel epigenetic regulatory network in which the CaMYB61-CaAFR1 molecular module participating in the regulation of K(hib) levels and biosynthesis of cellulose and hemicellulose for the first time.
关键词：
CRISPR/Cas9;eukaryotic translation initiation factor 4E (eIF4E);watermelon
摘要：
Watermelon is one of the most important cucurbit crops, but its production is seriously affected by viral infections. Although eIF4E proteins have emerged as the major mediators of the resistance to viral infections, the mechanism underlying the contributions of eIF4E to watermelon disease resistance remains unclear. In this study, three CleIF4E genes and one CleIF(iso)4E gene were identified in the watermelon genome. Among these genes, CleIF4E1 was most similar to other known eIF4E genes. To investigate the role of CleIF4E1, CRISPR/Cas9 technology was used to knock out CleIF4E1 in watermelon. One selected mutant line had an 86 bp deletion that resulted in a frame-shift and the expression of a truncated protein. The homozygous mutant exhibits developmental defects in plant growth, leaf morphology and reduced yield. Furthermore, the mutant was protected against the zucchini yellow mosaic virus, but not the cucumber green mottled mosaic virus. In summary, this study preliminarily clarified the functions of eIF4E proteins in watermelon. The generated data will be useful for elucidating eIF4E-related disease resistance mechanisms in watermelon. The tissue-specific editing of CleIF4E1 in future studies may help to prevent adverse changes to watermelon fertility.
摘要：
The research is aimed to elucidate the role of plant hormones in regulating the development of hybrid embryos in Hydrangea macrophylla. Fruits from the intraspecific cross of H. macrophylla 'Otaksa' × 'Coerulea' were selected at the globular, heart, and torpedo stages of embryo development. Transcriptome sequencing and differential gene expression analysis were conducted. The results showed that fruit growth followed a single "S-shaped growth curve, with globular, heart, and torpedo embryos appearing at 30, 40, and 50 d post-pollination, respectively, and the embryo maintaining the torpedo shape from 60 to 90 d. A total of 12,933 genes was quantified across the three developmental stages, with 3359, 3803, and 3106 DEGs in the S1_vs_S2, S1_vs_S3, and S2_vs_S3 comparisons, respectively. Among these, 133 genes related to plant hormone biosynthesis and metabolism were differentially expressed, regulating the synthesis and metabolism of eight types of plant hormones, including cytokinin, auxin, gibberellin, abscisic acid, and jasmonic acid. The pathways with the most differentially expressed genes were cytokinin, auxin, and gibberellin, suggesting these hormones may play crucial roles in embryo development. In the cytokinin pathway, CKX (Hma1.2p1_0579F.1_g182670.gene, Hma1.2p1_1194F.1_g265700.gene, and NewGene_12164) genes were highly expressed during the globular embryo stage, promoting rapid cell division in the embryo. In the auxin pathway, YUC (Hma1.2p1_0271F.1_g109005.gene and Hma1.2p1_0271F.1_g109020.gene) genes were progressively up-regulated during embryo growth; the early response factor AUX/IAA (Hma1.2p1_0760F.1_g214260.gene) was down-regulated, while the later transcriptional activator ARF (NewGene_21460, NewGene_21461, and Hma1.2p1_0209F.1_g089090.gene) was up-regulated, sustaining auxin synthesis and possibly preventing the embryo from transitioning to maturity. In the gibberellin pathway, GA3ox (Hma1.2p1_0129F.1_g060100.gene) expression peaked during the heart embryo stage and then declined, while the negative regulator GA2ox (Hma1.2p1_0020F.1_g013915.gene) showed the opposite trend; and the gibberellin signaling repressor DELLA (Hma1.2p1_1054F.1_g252590.gene) increased over time, potentially inhibiting embryo development and maintaining the torpedo shape until fruit maturity. These findings preliminarily uncover the factors affecting the development of hybrid H. macrophylla embryos, laying a foundation for further research into the regulatory mechanisms of H. macrophylla hybrid embryo development.
摘要：
<jats:p>Seedless is a highly valued commercial characteristic in the citrus industry, both for fresh consumption and for processed markets. In this study, the ‘Succari Sweet Orange’ (WT) and its seedless mutant ‘Juxiangyuan’ (MT), which originated from a bud mutation, were selected to study the formation of a citrus seedless phenotype. Microscopic analysis of MT’s floral organs, including anther and ovary cross-sections, provides insights into its seedless phenotype compared to the original seeded cultivar. Additionally, pollen features, viability, and in vitro germination were examined to determine the cause of seedlessness. MT exhibited significant developmental deformities in both male and female gametes, with pollen grain analysis indicating a high rate of deformity (41.48%), low viability (9.59%), and minimal in vitro germination (9.56%). Hybridization experiments were conducted to assess male and female sterility and pollen incompatibility. Both WT and MT exhibited parthenocarpic development. Notably, MT fruit produced with an average of 3.51 seeds pollinated to WT, despite severe pollen abortion of MT. MT, however, produced seedless fruit through self-breeding or cross-breeding with other varieties, demonstrating stable female sterility. Despite reduced pollen quantity and viability in the seedless mutant ‘Juxiangyuan’, its seedlessness primarily stems from female sterility. This study contributed to a deeper understanding of seedless formation in ‘Juxiangyuan’ and provided valuable information relevant to its commercial cultivation.</jats:p>
关键词：
Congou black tea;mixed varieties;non-violate components;violate components
摘要：
The eight trigrams represent the Chinese culture of tolerance and acceptance and express the richness of the biochemical composition and quality of the mixed processing black tea. Summary Congou black tea is mainly processed from single variety leaves, with obvious variety characteristics. This study investigated the effects of mixed processing withered leaves varieties on sensory quality, the volatile and non‐volatile compounds of seven Congou black tea samples. Sensory quality evaluation revealed that the Congou black tea with three leaves varieties were fresher, more floral and had coordinate taste. The total quality score was in the order: MPH > H > M&H > M > M&P > H&P > P. However, samples MPH and M&H have a higher content of theaflavins and amino acids, especially theanine. Furthermore, 130 volatile substances were identified in seven black teas by using HS‐SPME/GC–MS. M&H and MPH have more aroma types and total amount than that of M, P and H. The mixed processing of withered leaves may fully use the catalysis of endogenous enzymes to increase the 19 kinds of black tea key aromas including Benzyl alcohol, trans‐2‐hexenyl hexanoate, Hexyl hexanoate and Methyl jasmonate. Thus, blended processing can enhance the taste, aroma and LC quality of black tea.
摘要：
Soil microbial activity is generally limited by the availability of carbon (C), nitrogen (N), or phosphorus (P) in agricultural ecosystems. Soil ecoenzymatic activity (EEA), ecoenzymatic stoichiometry (EES), and vector characteristics were examined to assess microbial nutrient limitation. Investigating soil microbial nutrient limitation can provide insight into nutrient cycling in tea plantations with different tea cultivars. However, the dynamics of different tea cultivars on soil microbial nutrient limitations and their effect on tea quality remains poor. To address this issue, soil and plant samples were collected from a tea plantation cultivating five representative tea cultivars in Hunan Province, China. Baojing Huangjincha No. 1 (HJC1) and Huangjincha No. 2 (HJC2) were the extra early-sprouting cultivars, Zhuyeqi (ZYQ) and Zijuan (ZJ) were the middle-sprouting cultivars, and Zhenghedabai (ZHDB) was the late-sprouting cultivar, respectively. The results indicated that differences in EEA and EES were significant among five treatments. Notably, ZYQ and ZJ exhibited markedly lower activities of carbon (C), nitrogen (N), and phosphorus (P) acquiring enzymes compared to HJC1 and HJC2, whereas ZHDB showed significantly higher ecoenzymatic activities. Despite a general limitation in C and P for soil microorganisms across all cultivars (VL ranging from 1.42 to 1.59 and VA ranging from 58.70 degrees to 62.66 degrees), the degree of microbial nutrient limitation varied. Specifically, ZYQ experienced a pronounced P limitation (VA = 62.66 degrees, N:P enzyme = 0.52), as evidenced by increased vector angles and decreased N:P enzyme values. Although C limitation was most pronounced in ZYQ (VL = 1.59), it did not significantly differ among the cultivars. These findings suggest that tea cultivars can influence the P limitation of microbial communities. Further analysis revealed that microbial nutrient limitations might adversely affect tea quality via impeding enzyme secretion. This study highlights the critical role of nutrient cycling within the soil-microorganism-plant ecosystem and emphasizes the influence of soil microbial nutrient limitations on tea quality within tea plantations. It is recommended that in the management of tea plantation fertilization, managers need to consider the influence of cultivars and develop specialized cultivar fertilizers.
通讯机构：
[Fang, K ] H;Hunan Agr Univ, Coll Informat & Intelligent Sci & Technol, Changsha 410128, Peoples R China.
关键词：
mulberry leaf Fu brick tea;volatile compounds;aroma attributes;sensory evaluation;OPLS-DA
摘要：
This study aimed to investigate the aroma effects of key volatile compounds in a new type of mulberry leaf Fu brick teas (MTs) and traditional Fu brick teas (FTs). Headspace solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS), sensory evaluation, and chemometrics were used to determine the differences in key flavour qualities between the two. The results showed that a total of 139 volatile components were identified, with aldehydes, ketones, and alcohols dominating. Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) combined with the odour activity value (OAV) showed that seven aroma compounds had an OAV > 10, including 2-(4-methylcyclohex-3-en-1-yl) propan-2-ol with floral and fruity aroma and green attributes, 6-methylhept-5-en-2-one, (E)-6,10-dimethyl-5,9-Undecadien-2-one, (3E,5E)-octa-3,5-dien-2-one, Benzaldehyde, and (E)-3,7,11,15-tetramethylhexadec-2-en-1-ol, which were more abundant in MTs than FTs; Cedrol with sweet aroma attributes was more consistent in MTs than FTs, and we suggest that these odour compounds are important aroma contributors to MTs. Taken together, these findings will provide new insights into the mechanism of formation of the characteristic attributes of aroma in MTs.
摘要：
Uncaria rhynchophylla is an evergreen vine plant, belonging to the Rubiaceae family, that is rich in terpenoid indole alkaloids (TIAs) that have therapeutic effects on hypertension and Alzheimer’s disease. GATA transcription factors (TF) are a class of transcription regulators that participate in the light response regulation, chlorophyll synthesis, and metabolism, with the capability to bind to GATA cis-acting elements in the promoter region of target genes. Currently the charactertics of GATA TFs in U. rhynchophylla and how different light qualities affect the expression of GATA and key enzyme genes, thereby affecting the changes in U. rhynchophylla alkaloids have not been investigated. In this study, 25 UrGATA genes belonging to four subgroups were identified based on genome-wide analysis. Intraspecific collinearity analysis revealed that only segmental duplications were identified among the UrGATA gene family. Collinearity analysis of GATA genes between U. rhynchophylla and four representative plant species, Arabidopsis thaliana, Oryza sativa, Coffea Canephora, and Catharanthus roseus was also performed. U. rhynchophylla seedlings grown in either red lights or under reduced light intensity had altered TIAs content after 21 days. Gene expression analysis reveal a complex pattern of expression from the 25 UrGATA genes as well as a number of key TIA enzyme genes. UrGATA7 and UrGATA8 were found to have similar expression profiles to key enzyme TIA genes in response to altered light treatments, implying that they may be involved in the regulation TIA content. In this research, we comprehensively analyzed the UrGATA TFs, and offered insight into the involvement of UrGATA TFs from U. rhynchophylla in TIAs biosynthesis. Identify the GATA gene family from U. rhynchophylla and analyze the expression levels of key enzyme genes and UrGATA genes under different lights.
期刊：
Current Plant Biology,2024年38:100330 ISSN：2214-6628
通讯作者：
Huan Zhao<&wdkj&>Qi Tang
作者机构：
[Yingying Shao; Detian Mu; Zhiguo Lu; Yu Zhou; Ying Lu; Lina Zhu; Yao Zhang; Xinghui Liu; Qi Tang] College of Horticulture, National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Hunan Agricultural University, Changsha 410128, China;[Limei Pan; Ya Qin] Guangxi Key Laboratory of for High-Quality Formation and Utilization of Dao-Di Herbs, National Center for TCM Inheritance and Innovation, Guangxi Botanical Garden of Medicinal Plants, Nanning, China;[Huan Zhao] School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China;CSIRO Agriculture and Food, Canberra, ACT 2601, Australia;[Deyou Qiu] State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
通讯机构：
[Huan Zhao] S;[Qi Tang] C;College of Horticulture, National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Hunan Agricultural University, Changsha 410128, China<&wdkj&>School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China
摘要：
Uncaria rhynchophylla (Gouteng), as an evergreen woody vine belong to Rubiaceae family, is a traditional medicinal herb in China. Its terpenoid indole alkaloids (TIAs), which have good antidepressant and combined therapeutic effects on Alzheimer's disease, have attracted widespread attention. However, the content of TIAs is relatively low in U.rhynchophylla, which is unable to meet the growing market demand. The basic helix loop-helix (bHLH) transcription factor family exists in all three eukaryotic kingdoms and can participate in regulating secondary metabolite pathways. So far, there has been no comprehensive analysis of the bHLH gene in U. rhynchophylla, and their role in TIAs is almost unknown. In this study, a total of 171 UrbHLH genes (UrbHLHs) were unevenly distributed on 22 chromosomes and divided into 23 subfamilies. In addition, the physicochemical properties of UrbHLHs were analyzed. Most UrbHLHs in each subgroup had similar gene structures and conserved motifs. Intraspecific collinearity analysis showed that UrbHLH1 may be related to the biosynthesis of TIAs. Subcellular localization experiments revealed that UrbHLH1 is located in the nucleus; Dual luciferase reporter gene analysis (Dual-LUC) showed that UrbHLH1 could activate the expression of UrG10H and Ur10HGO in the TIAs synthesis pathway of U. rhynchophylla. Finally, using yeast one hybrid (Y1H) it was found that the promoter regions of these two genes both have E-box binding elements, which can be bound by UrbHLH1 and produced strong interactions. Therefore, UrbHLH1 may participate in the synthesis of TIAs pathway. In conclusion, this study provides foundation data on the role of UrbHLH transcription factors in regulating TIAs of U. rhynchophylla.
摘要：
The object of this study was to trace TwHf-derived toxins in raw honey and clarify their acute toxic effect related to the addition of honey or sugars. TwHf flowers, raw honey from TwHf planting base and from beekeepers in high-risk area were detected using LC-MS/MS. The results revealed five target toxins were detected in TwHf flowers; only celastrol was detected in one raw honey sample, as a food safety risk factor, celastrol had been traced back to TwHf flowers from raw honey. In a series of acute toxic tests on zebrafish, toxification effects were observed when honey, mimic honey or sugar was mixed with toxins. The degree of toxicity varied among various sugar-based solutions. At the same mass concentration, they follow this order: raw honey/mimic honey > glucose > fructose. The main toxic target organs of triptolide and celastrol with honey were the heart and liver.
通讯作者：
Jian'an Huang<&wdkj&>Zhonghua Liu<&wdkj&>Jian'an Huang Jian'an Huang Jian'an Huang<&wdkj&>Zhonghua Liu Zhonghua Liu Zhonghua Liu
作者机构：
[Hongzhe Zeng; Kuofei Wang; Changwei Liu; Jie Ouyang; Shuai Wen; Fang Zhou; Jingyi Tang; Wenwen Fang; Lin Yue; Jian'an Huang; Zhonghua Liu; Hongzhe Zeng Hongzhe Zeng Hongzhe Zeng; Kuofei Wang Kuofei Wang Kuofei Wang; Changwei Liu Changwei Liu Changwei Liu; Jie Ouyang Jie Ouyang Jie Ouyang; Shuai Wen Shuai Wen Shuai Wen; Fang Zhou Fang Zhou Fang Zhou; Jingyi Tang Jingyi Tang Jingyi Tang; Wenwen Fang Wenwen Fang Wenwen Fang; Lin Yue Lin Yue Lin Yue; Jian'an Huang Jian'an Huang Jian'an Huang; Zhonghua Liu Zhonghua Liu Zhonghua Liu] Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China, Hunan Agricultural University, Changsha, China
通讯机构：
[Jian'an Huang; Zhonghua Liu; Jian'an Huang Jian'an Huang Jian'an Huang; Zhonghua Liu Zhonghua Liu Zhonghua Liu] K;Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China, Hunan Agricultural University, Changsha, China
摘要：
(1) This study may be the first study to evaluate the effects of oolong tea with different storage time in db/db T2DM mice.(2) All three aged oolong tea extracts (2001, 2011, 2020) can effectively alleviate type 2 diabetes mellitus (T2DM), and 2011 aged oolong tea extract exhibited relatively optimal ability to alleviate T2DM.(3) With storage time of oolong tea increasing, oolong tea’s ability to inhibit fat ectopic deposition in liver increases and the ability to activate INSR/IRS/PI3K/AKT/GSK‐3β/GYS‐mediated hepatic glycogen synthesis signaling pathway decreases. Abstract An important concern for tea consumers is whether appropriate storage can effectively improve the ability of oolong tea to alleviate type 2 diabetes mellitus (T2DM). In this study, the antidiabetic effects of three aged oolong tea (2001, 2011, and 2020) extracts (aged TEs) in db/db T2DM mice were investigated and compared for the first time. The results showed that aged oolong tea extracts (aged TEs) alleviated the abnormal fasting blood glucose levels, lipid profiles, insulin resistance, and reduced ectopic fat deposition in liver. Moreover, aged TEs alleviated T2DM‐related tissue damage and activated insulin receptor (INSR)/insulin receptor substrate (IRS)/phosphatidylinositol‐3 kinase (PI3K)/phosphatidylinositol‐3 kinase (AKT)/glycogen synthase kinase 3 beta (GSK‐3β)/glycogen synthase (GYS)‐mediated hepatic glycogen synthesis signaling pathway. In addition, aged TEs altered gut microbiota composition and gut metabolite profiles associated with T2DM. Together, all three aged TEs (400 mg/kg/day in mice, a human equivalent dose of 7 g/60 kg/day), especially 2011, can effectively alleviate T2DM, and proper storage can effectively improve the ability of oolong tea to alleviate T2DM.
摘要：
The objective of this study is to explore the influence of extraction factors, including extraction temperatures, extraction time, and tea-water ratios, on the sensory quality and aroma characteristics of instant Pu-erh tea (IPET). Sensory evaluation, quantitative descriptive analysis (QDA) and HS-SPME-GC x GC-TOF/MS were utilized for analysis. The result showed that the optimal process condition of IPET was a tea-to-water ratio 1:8, an extraction temperature 75 C-degrees, and an extraction time 60 min. A total of 235 volatile compounds were identified and 65 key odor-active compounds with ROAV>1 in all samples. Based VIP > 1, 19 key differential odor-active compounds were identified, including linalool oxide I, 1-dodecanol, linalool oxide II, etc. Further Pearson correlation analysis of key differential odor-active compounds and aroma characteristics showed that positive correlations between woody and ethyl nonanoate and 1-dodecanol, and between herbal and 1-methylnaphthalene. This research provides theoretical support for the production of high-quality IPET.
摘要：
Liquid chromatography-mass spectrometry (LC-MS) combined with multivariate analysis were used to characterize the nonvolatile compounds of broken green tea and explore the effect of isolated scenting on metabolic profile and taste quality of broken green tea in this research. A total of 236 nonvolatile compounds were identified and 13 compounds were believed to be the key characteristic taste compounds of scented broken green tea. Meanwhile, the optimal isolated scenting time of broken green tea was determined to be 10h based on the sensory evaluation and PLS results. The contents and types of flavonoids, organic acids and catechins lead to the difference of taste quality at different scenting times. Overall, these findings provided a theoretical basis for scenting to improve the taste of broken green tea, and provide a new idea for improving the taste of broken green tea.
通讯机构：
[Xia, B ] H;Hunan Agr Univ, Coll Food Sci & Technol, East Renmin Rd, Changsha 410128, Hunan, Peoples R China.
关键词：
Chitin degradation;Chitin-binding domain;Enzyme engineering;Fibronectin III domain;N-acetyl-D-glucosamine
摘要：
N-acetyl-D-glucosamine and its dimer are degradation products of chitin waste with great potential in therapeutic and agricultural applications. However, the hydrolysis of insoluble chitin by chitinases remains a major bottleneck. This study investigated the biochemical properties and catalytic mechanisms of PoChi chitinase obtained from Penicillium oxalicum with a focus on enhancing its efficiency during the degradation of insoluble chitin. Recombinant plasmids were engineered to incorporate chitin-binding (ChBD) and/or fibronectin III (FnIII) domains. Notably, PoChi-FnIII-ChBD exhibited the highest substrate affinity (K(m)=2.7mg/mL) and a specific activity of 15.4U/mg, which surpasses those of previously reported chitinases. These findings highlight the potential of engineered chitinases in advancing industrial biotechnology applications and offer a promising approach to more sustainable chitin waste management.
