Myrica Rubra Research Articles

不同林分土壤磷形态与磷酸酶特征

PDF HTML阅读 XML下载 导出引用 引用提醒 不同林分土壤磷形态与磷酸酶特征 DOI: 10.5846/stxb202102130434 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（32171761，U21A20187）；中南林业科技大学研究生科技创新基金项目（CX20191006，CX202102023） Characteristics of soil phosphorus fractions and phosphatases activity in different plantations Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以湖南省平江县国有芦头林场的次生林以及经人工翻垦种植的油茶（Camellia oleifera）、黄桃（Amygdalus persica）、杨梅（Myrica rubra）和杉木（Cunninghamia lanceolata）四种人工林为研究对象，比较了不同林分土壤理化性质、磷酸酶活性与磷形态特征，分析了三者之间的相关性，探讨了次生林转变为人工林后，土壤磷形态和磷酸酶的变化特征以及驱动土壤磷素形态变化的关键因子。结果表明：（1）次生林土壤有机碳（SOC），全氮（TN）、铵态氮（NH4+-N）含量与磷酸酶活性显著高于其他四种林分。（2）五种林分中土壤残余磷（Residual-P）含量最高，是林地土壤主要的磷素存在形态。林分转变后，黄桃林与杉木林树脂提取态无机磷（Resin-Pi）显著增加，黄桃林与油茶林NaHCO3提取态磷（NaHCO3-Pi、NaHCO3-Po）含量显著增加，而四种人工林的NaOH提取态有机磷（NaOH-Po）含量均显著降低。可利用磷、中等可利用磷与稳定态磷含量及其占全磷的比例在五种林分中差异显著，其中黄桃林与油茶林可利用磷占全磷比例较高；杨梅林和杉木林中等可利用磷占总磷比例较高；油茶林与次生林中稳定态磷所占全磷比例较高。（3）相关分析表明土壤中可利用磷与全钾（TK）呈显著正相关，中等可利用磷与硝态氮（NH3--N）呈显著正相关，稳定态磷与SOC、TN、NH4+-N均呈显著正相关，磷酸酶活性与SOC、TN、NH4+-N显著正相关。综上所述，次生林转变为人工林不仅改变了土壤中总磷的含量，而且影响了不同磷形态之间的转化，导致土壤中磷的赋存状况发生改变。 Abstract:In order to clarify the differences in soil phosphorus forms and phosphatase activities in different forest types, we investigated the characteristics of soil properties, phosphorus (P) fractions, and phosphatase activities in a secondary forest and four artificial plantations (Camellia oleifera, Amygdalus persica, Myrica rubra and Cunninghamia lanceolata) in Lutou National Station for Scientific Observation and Research of Forest Ecosystems, Hunan Province. Correlations among soil properties, phosphorus fractions and phosphatase activities were analyzed, and the influencing factors driving the differences in soil phosphorus forms and phosphatase activities were identified. The results showed that:(1) the contents of soil organic carbon (SOC), total nitrogen (TN), ammonium nitrogen (NH4+-N) and the activities of phosphatase in the secondary forest were higher than in the four plantations. (2) the content of residual-P was the highest in the five forest types, and residual-P was the dominant phosphorus form in forest soils. After forest conversion, resin extractable inorganic P (Resin-Pi) increased significantly in Amygdalus persica and Cunninghamia lanceolata plantations. The contents of NaHCO3 extractable P (NaHCO3-Pi, NaHCO3-Po) increased significantly in Amygdalus persica and Camellia oleifera plantations, whereas the content of NaOH extracted organic P (NaOH-Po) decreased significantly in all plantations. The contents and proportions of easily-available P, moderately-available P and non-available P in soils differed significantly among the five forest types. The proportion of easily-available P in total P was higher in Amygdalus persica and Camellia oleifera plantations than in other forests, while a higher proportion of moderately-available P in total P was found in Myrica rubra plantations and Cunninghamia lanceolata plantations. The proportion of non-available P in total P was higher in Camellia oleifera and the secondary forest compared with other forests. (3) correlation analysis demonstrated that easily-available P was positively correlated with total potassium (TK), moderately-available P was positively correlated with nitrate nitrogen (NH3--N), non-available P was positively correlated with SOC, TN, NH4+-N, and phosphatase activity was positively correlated with SOC, TN, NH4+-N. In conclusion, the conversion of secondary forest to plantations not only changed the soil total P contents, but also affected the transformation of phosphorus forms, resulted in the differences of the occurrence of P in soil. 参考文献 相似文献 引证文献

First Report of Epicoccum sorghinum Causing leaf spot on Platostoma palustre in Malaysia.

Platostoma palustre (family Lamiaceae), locally known as 'Black Cincau', is an herb processed as herbal drinks in Malaysia. In November 2021, brown lesions were observed on leaf samples of P. palustre with an incidence of approximately 10% in a nursery in Penampang, Sabah province (5°55'30.4"N 116°04'35.7"E). The lesions developed into larger chlorotic spots with aging of leaves. Five samples of infected leaves were collected, excised (5 × 5 mm), and then surface sterilized with 75% ethanol for 1 minute, washed with 2% sodium hypochlorite solution for 1 minute, rinsed, and air dried before inoculated onto potato dextrose agar (PDA). Inoculated plates were incubated at 25°C. Three isolates were isolated from the samples, which showed cottony aerial mycelia with light purple concentric rings appeared on the reverse side of the colony after 3 days. Pycnidia which were spheroid and measured 64.0 to 114.1 × 41.2 to 88.0 μm (n= 30). Conidia, unicellular, hyaline, oval and measured 3.8 to 4.9 × 2.0 to 2.7 μm (n= 30). Chlamydospores were observed, either unicellular or multicellular. NaOH test on oatmeal agar positive, brownish red. Further, the genomic DNA of pathogens (UMS, UMS02 and UMS03) was extracted from fresh mycelia (7-day-old) using lysis buffer. Large Sub Unit (LSU), β-tubulin (tub) and RNA polymerase II (RPB2) gene were amplified using LR0R/LR7, T10/Bt2b and RPB2-5F2/RPB2-7cR primers (Rehner and Samuel, 1994; O'Donnell and Cigelnik, 1997; Liu et al. 1999) respectively. The sequences of isolate UMS, UMS02 and UMS03 which deposited in Genbank were OM238129, ON386254, ON386255 (LSU), OM048108, ON366806, ON366807 (tub), and ON003417, ON366804, ON366805 (RPB2). They had 99-100% homology to the LSU (1328/1328 bp) of Epicoccum sorghinum isolate Lido01 (OM501128), tub (422/425 bp) of isolate BJ-F1 (MF987525), and RPB2 (596/596 bp) of isolate HYCX2 (MK836295). Phylogenetic analysis by maximum likelihood method generated from the combined tub, LSU and RPB2 sequences indicated that the isolates formed a supported clade to the related Epicoccum sorghinum type sequences. Morphological, NaOH test and molecular characterization matched the description of E. sorghinum (Boerema et al. 2004; Li et al. 2020). Koch's postulates were performed by spray inoculation (106 conidia/mL) on the leaves of three healthy P. palustre seedlings with isolate UMS, while water was sprayed on three additional P. palustre seedlings served as controls. The plants were maintained in a greenhouse at room temperature 25 to 28°C with a relative humidity of 80 to 90%. All inoculated plants exhibited the symptoms similar to those of the nursery collection occurred after 8 days post inoculation. No symptoms occurred on controls. The experiment was repeated twice. The reisolated pathogen was morphologically identical to E. sorghinum. E. sorghinum was reported previously on Myrica rubra in China (Li et al. 2020). To our knowledge, this is the first report of E. sorghinum causing leaf spot on P. palustre in Malaysia. Our findings expand the host range of E. sorghinum in Malaysia.

Extracts from Chinese Bayberry Leaves as Natural Additives Effectively Inhibit the Formation of Biogenic Amines in the Factory-Grade Brewing Soy Sauce

Extracts from Chinese Bayberry Leaves as Natural Additives Effectively Inhibit the Formation of Biogenic Amines in the Factory-Grade Brewing Soy Sauce

Visual preference of plant features in different living environments using eye tracking and EEG.

Plants play a very important role in landscape construction. In order to explore whether different living environment will affect people's preference for the structural features of plant organs, this study examined 26 villagers and 33 college students as the participants, and pictures of leaves, flowers and fruits of plants as the stimulus to conduct eye-tracking and EEG detection experiments. We found that eye movement indicators can explain people's visual preferences, but they are unable to find differences in preferences between groups. EEG indicators can make up for this deficiency, which further reveals the difference in psychological and physiological responses between the two groups when viewing stimuli. The final results show that the villagers and the students liked leaves best, preferring aciculiform and leathery leaves; solitary, purple and capitulum flowers; and medium-sized, spathulate, black and pear fruits. In addition, it was found that the overall attention of the villagers when watching stimuli was far lower than that of the students, but the degree of meditation was higher. With regard to eye movement and EEG, the total duration of fixations is highly positively correlated with the number of fixations, and the average pupil size has a weak negative correlation with attention. On the contrary, the average duration of fixations has a weak positive correlation with meditation. Generally speaking, we believe that Photinia×fraseri, Metasequoia glyptostroboides, Photinia serratifolia, Koelreuteria bipinnata and Cunninghamia lanceolata are superior landscape building plants in rural areas and on campuses; Pinus thunbergii, Myrica rubra, Camellia japonica and other plants with obvious features and bright colours are also the first choice in rural landscapes; and Yulania biondii, Cercis chinensis, Hibiscus mutabilis and other plants with simple structures are the first choice in campus landscapes. This study is of great significance for selecting plants for landscape construction and management according to different environments and local conditions.

New insights into the function of plant tannase with promiscuous acyltransferase activity.

Plant tannases (TAs) or tannin acyl hydrolases, a class of recently reported carboxylesterases in tannin-rich plants, are involved in the degalloylation of two important groups of secondary metabolites: flavan-3-ol gallates and hydrolyzable tannins. In this paper, we have made new progress in studying the function of tea (Camellia sinensis) (Cs) TA-it is a hydrolase with promiscuous acyltransferase activity invitro and invivo and promotes the synthesis of simple galloyl glucoses and flavan-3-ol gallates in plants. We studied the functions of CsTA through enzyme analysis, protein mass spectrometry, and metabolic analysis of genetically modified plants. Firstly, CsTA was found to be not only a hydrolase but also an acyltransferase. In the two-step catalytic reaction where CsTA hydrolyzes the galloylated compounds epigallocatechin-3-gallate or 1,2,3,4,6-penta-O-galloyl-β-d-glucose into their degalloylated forms, a long-lived covalently bound Ser159-linked galloyl-enzyme intermediate is also formed. Under nucleophilic attack, the galloyl group on the intermediate is transferred to the nucleophilic acyl acceptor (such as water, methanol, flavan-3-ols, and simple galloyl glucoses). Then, metabolic analysis suggested that transient overexpression of TAs in young strawberry (Fragaria × ananassa) fruits, young leaves of tea plants, and young leaves of Chinese bayberry (Myrica rubra) actually increased the total contents of simple galloyl glucoses and flavan-3-ol gallates. Overall, these findings provide new insights into the promiscuous acyltransferase activity of plant TA.

Comparative analysis of the potential physiological and molecular mechanisms involved in the response to root zone hypoxia in two rootstock seedlings of the Chinese bayberry via transcriptomic analysis.

The negative effects of waterlogging can be effectively improved through the use of waterlogging-resistant rootstocks. However, the underlying physiological and molecular mechanisms of Chinese bayberry (Morella rubra) rootstock tolerance to waterlogging have not yet been investigated. This study aims to unravel the molecular regulation mechanisms underlying waterlogging-tolerant rootstocks. Two rootstocks, Morella cerifera (tolerant) and Morella rubra (sensitive), were selected for root zone hypoxia treatments, assessments of hormone levels and antioxidant enzyme activity, and transcriptomic analysis. While the contents of abscisic acid (ABA) and brassinosteroid (BR) in the roots of M. rubra decreased significantly after root zone hypoxia treatment, there were no significant changes in M. cerifera. Both the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content increased in M. cerifera but were decreased in M. rubra. Transcriptome sequencing identified 1,925 (928 up- and 997 downregulated) and 733 (278 up- and 455 downregulated) differentially expressed genes (DEGs) in the two rootstocks. The gene set enrichment analysis showed that 84 gene sets were enriched after root zone hypoxia treatment, including 57 (35 up- and 22 downregulated) and 14 (five up- and nine downregulated) gene sets derived from M. cerifera and M. rubra, respectively, while the remaining 13 gene sets were shared. KEGG pathway analysis showed specific enrichment in six pathways in M. cerifera, including the mitogen-activated protein kinase (MAPK), tyrosine metabolism, glycolysis/gluconeogenesis, ribosome, cyanoamino acid metabolism, and plant-pathogen interaction pathways. Overall, these results provide preliminary insights into the molecular mechanisms of Chinese bayberry tolerance to waterlogging.

Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins alleviate insulin-resistance via activating PI3K/AKT pathway in HepG2 cells

Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins (BLPs) were natural bioactive compounds in the treatment of obesity and diabetes with a unique structural characteristic. This study aimed to investigate the effect of BLPs on hepatic glucose metabolism in insulin-resistant HepG2 cells and elucidate the underlying mechanism. With the supplementation of BLPs, the glucose consumption and glucose uptake in IR-HepG2 cells were increased. BLPs promoted glycogen synthesis via up-regulating p-GSK3β and GYS2 expression, and attenuated gluconeogenesis by down-regulating PEPCK and G6Pase expression. It was attributed to the activation of PI3K/AKT signal pathway by BLPs, which was confirmed using the PI3K inhibitor LY294002. Moreover, BLPs remarkably reduced the expression of miR-29a, miR-423 and miR-122, which involved in hepatic glucose metabolism. Our results provide an insight of the hypoglycemic potential of BLPs on the hepatic glucose metabolism, suggesting that BLPs can be further used as a novel ingredient in functional food.

Pulsed light reduces postharvest losses of Chinese bayberries by affecting fungal microbiota during cold storage

Non-thermal sterilization technology is considered a safe and effective approach in controlling postharvest losses of fruit. In this study, the effects of pulsed light (PL) on qualities of Chinese bayberries during storage at 10 °C, 95% RH for 12 d were investigated. At the same time, high-throughput sequencing was operated to identify fungal microbiota on Chinese bayberries. The results showed that PL treatment could inhibit the decay incidence and polyphenol oxidase (PPO) activity, maintain fruit firmness and enhance phenylalanine ammonia-lyase (PAL) activity, with no effect on titratable acid (TA), total soluble solids (TSS), malondialdehyde (MDA) content and superoxide dismutase (SOD) activity. Additionally, the PL treatment maintained alpha diversity and altered beta diversity. At the species level, the abundance of Monographella nivalis and Colletotrichum cordylinicota were reduced in PL samples, while Hanseniaspora uvarum and Diaporthe spp were enriched. M. nivalis and C. cordylinicota were positively correlated with weight loss and decay index according to canonical correspondence analysis (CCA). The data of microbial correlation network indicated that PL treatment reduced pathogenic fungal microbiotas and made fungal community more complex and steadier. This study demonstrated that PL affects fungal community by inhibiting plant pathogens, increasing the amounts of endophytes and consolidating microbial networks. It provides new insights into the dynamics of the microbiome of Chinese bayberries after PL treatment.

Comparative plastomes of Carya species provide new insights into the plastomes evolution and maternal phylogeny of the genus.

Carya, in the Juglandiodeae subfamily, is to a typical temperate-subtropical forest-tree genus for studying the phylogenetic evolution and intercontinental disjunction between eastern Asia (EA) and North America (NA). Species of the genus have high economic values worldwide for their high-quality wood and the rich healthy factors of their nuts. Although previous efforts based on multiple molecular markers or genome-wide SNPs supported the monophyly of Carya and its two EA and NA major subclades, the maternal phylogeny of Carya still need to be comprehensively evaluated. The variation of Carya plastome has never been thoroughly characterized. Here, we novelly present 19 newly generated plastomes of congeneric Carya species, including the recently rediscovered critically endangered C. poilanei. The overall assessment of plastomes revealed highly conservative in the general structures. Our results indicated that remarkable differences in several plastome features are highly consistent with the EA-NA disjunction and showed the relatively diverse matrilineal sources among EA Carya compared to NA Carya. The maternal phylogenies were conducted with different plastome regions and full-length plastome datasets from 30 plastomes, representing 26 species in six genera of Juglandoideae and Myrica rubra (as root). Six out of seven phylogenetic topologies strongly supported the previously reported relationships among genera of Juglandoideae and the two subclades of EA and NA Carya, but displayed significant incongruencies between species within the EA and NA subclades. The phylogenetic tree generated from full-length plastomes demonstrated the optimal topology and revealed significant geographical maternal relationships among Carya species, especially for EA Carya within overlapping distribution areas. The full-length plastome-based phylogenetic topology also strongly supported the taxonomic status of five controversial species as separate species of Carya. Historical and recent introgressive hybridization and plastid captures might contribute to plastome geographic patterns and inconsistencies between topologies built from different datasets, while incomplete lineage sorting could account for the discordance between maternal topology and the previous nuclear genome data-based phylogeny. Our findings highlight full-length plastomes as an ideal tool for exploring maternal relationships among the subclades of Carya, and potentially in other outcrossing perennial woody plants, for resolving plastome phylogenetic relationships.

Alcohol extracts of Chinese bayberry branch induce S-phase arrest and apoptosis in HepG2 cells.

The alcohol extracts of Chinese bayberry (Myrica rubra) branches (MRBE) are rich in flavonoids which have a variety of medicinal benefits, but their effects on human HepG2 were unknown. In this study, the effects of MRBE on HepG2 cell growth and its potential for inhibiting cancer were explored. The results displayed that MRBE inhibited HepG2 proliferation both by arresting cells in S phase and promoting apoptosis. Quantitative reverse-transcription PCR (qRT-PCR), western blotting, and immunofluorescence showed that MRBE induced S-phase arrest by upregulating p21, which in turn downregulated cyclin and cyclin-dependent kinase messenger RNA (mRNA) and protein. Apoptosis was induced by blocking the expression of BCL-2 and suppression of the Raf/ERK1 signaling pathways. These results indicated that MRBE may have the potential for treatment of human liver cancer, highlighting novel approaches for developing new pharmacological tools for the treatment of this deadly type cancer. Meanwhile, it provides a new direction for the medicinal added values of Chinese bayberry, which helped to broaden the diversified development of its industry chain.

Genome-wide analysis of UDP-glycosyltransferase gene family and identification of members involved in flavonoid glucosylation in Chinese bayberry (Morella rubra).

Glycosylation was catalyzed by UDP-glycosyltransferase (UGT) and was important for enriching diversity of flavonoids. Chinese bayberry (Morella rubra) has significant nutritional and medical values because of diverse natural flavonoid glycosides. However, information of UGT gene family was quite limited in M. rubra. In the present study, a total of 152 MrUGT genes clustered into 13 groups were identified in M. rubra genome. Among them, 139 MrUGT genes were marked on eight chromosomes and 13 members located on unmapped scaffolds. Gene duplication analysis indicated that expansion of MrUGT gene family was mainly forced by tandem and proximal duplication events. Gene expression patterns in different tissues and under UV-B treatment were analyzed by transcriptome. Cyanidin 3-O-glucoside (C3Glc) and quercetin 3-O-glucoside (Q3Glc) were two main flavonoid glucosides accumulated in M. rubra. UV-B treatment significantly induced C3Glc and Q3Glc accumulation in fruit. Based on comprehensively analysis of transcriptomic data and phylogenetic homology together with flavonoid accumulation patterns, MrUFGT (MrUGT78A26) and MrUGT72B67 were identified as UDP-glucosyltransferases. MrUFGT was mainly involved in C3Glc and Q3Glc accumulation in fruit, while MrUGT72B67 was mainly involved in Q3Glc accumulation in leaves and flowers. Gln375 and Gln391 were identified as important amino acids for glucosyl transfer activity of MrUFGT and MrUGT72B67 by site-directed mutagenesis, respectively. Transient expression in Nicotiana benthamiana tested the function of MrUFGT and MrUGT72B67 as glucosyltransferases. The present study provided valuable source for identification of functional UGTs involved in secondary metabolites biosynthesis in M. rubra.

Unveiling interaction mechanisms between myricitrin and human serum albumin: Insights from multi-spectroscopic, molecular docking and molecular dynamic simulation analyses

Myricitrin is a natural polyhydroxy flavonoid and is mainly derived from the bark and leaves of the Chinese Bayberry tree (Myrica rubra). It has different pharmacological activities, including antioxidative, anti-inflammatory, hypoglycemic, antiviral, liver protection and cholagogue properties, and may be added to foods, pharmaceuticals, and cosmetic products for antioxidant purposes. In this study, the interaction mechanism between myricitrin and human serum albumin (HSA) was investigated using spectroscopic methods, molecular docking techniques, and molecular dynamic simulations. We showed that the HSA/myricitrin interaction exhibited a static fluorescence quenching mechanism, and that binding processes were spontaneous in nature, with the main forces exemplified by hydrogen bonding, hydrophobic interactions, and electrostatic interactions. Fluorescence spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, synchronous fluorescence spectroscopy, three-dimensional (3D) fluorescence spectroscopy, micro-Fourier transform infrared spectroscopy (micro-FTIR), and circular dichroism (CD) spectroscopy showed that myricitrin binding altered the HSA conformation to some extent. Competitive binding and molecular docking studies showed that the preferred binding of myricitrin on HSA was in the sub-structural domain IIA (Site I); molecular dynamic simulations revealed that myricitrin interacted with HSA to produce a well stabilized complex, and it also generated a conformational change in HSA. The antioxidant capacity of the HSA-myricitrin complex was reduced when compared with free myricitrin. The identification of HSA-myricitrin binding mechanisms provides valuable insights for the application of myricitrin to the food and pharmaceutical industries.

Soil quality and r – K fungal communities in plantations after conversion from subtropical forest

Intensive clear-cutting of natural forests and conversion to monoculture plantations are ongoing worldwide, leading to the degradation of soil quality and microbial functions. Here, we compared soil quality index (SQI) and fungal communities in a natural forest (Forest) and four 5-year-old monoculture plantations, including Camellia oleifera (Oil), Amygdalus persica (Peach), Myrica rubra (Berry) and Cunninghamia lanceolate (Fir) in a subtropical region of China. After conversion, soil pH in the plantations rose up to 0.31, but organic carbon and total nitrogen contents, sucrase, acid protease, glutaminase, acid and alkaline phosphatase activities decreased by 83%, 59%, 40%, 64%, 66%, 94% and 59%, respectively. Correspondingly, the SQI dropped by 65%. High-throughput sequencing of the ITS1 region demonstrated an increase in α-diversity and a striking difference in β-diversity of fungi following conversion. Changes in the dominant fungal taxa following forest conversion to plantations were interpreted by r- and K-selection of life strategies. Conversion increased the fungal groups with r-strategies, such as Ascomycota and Zygomycota, but decreased the fungal groups with K-strategies, such as Basidiomycota. Genera affiliated to those phyla including Pseudophialophora, Rhytisma increased, but Russula decreased. Redundancy analysis and structural equation modeling indicated that the diversity and composition of fungal communities changed with soil degradation, which was mainly driven by increased pH and total phosphorus content, but decreased C/N ratio and C and N related enzymes activities. Overall, the conversion of forest to monoculture plantations decreased soil quality and the abundance of K-strategists, retarded the decomposition of persistent organic matter, but boosted the prevalence of r-strategists in a more diverse fungal community.

Cyanidin-3-O-glucoside extracted from the Chinese bayberry (Myrica rubra Sieb. et Zucc.) alleviates antibiotic-associated diarrhea by regulating gut microbiota and down-regulating inflammatory factors in NF-κB pathway.

Chinese bayberry has been used to treat diarrhea in China for more than 2,000 years, but the mechanism is not clear. Due to the extensive use of antibiotics, antibiotic-associated diarrhea (AAD) is becoming more and more common in clinic, but there is no effective drug for the treatment. The present study aimed to explore the therapeutic effect of Chinese bayberry on AAD for the first time, and explained the underlying mechanism from different aspects. The BALB/c mice model was established by intragastric administration of lincomycin (3 g/kg). Successfully modeled mice were treated with purified water, dried bayberry powder suspension (100 mg/kg), C3G suspension (40 mg/kg) and montmorillonite powder suspension (40 mg/kg), respectively. The changes of body weight, diarrhea index, diarrhea status score were recorded and calculated regularly. 16S rRNA gene sequencing, intestinal immunofluorescence and inflammatory factor detection were further performed. The treatment with dried bayberry powder suspension and C3G suspension could rapidly reduce the diarrhea score and diarrhea index, increase food intake and restore body weight gain. The gut microbiota richness and diversity were significantly increased after dried bayberry powder suspension and C3G suspension treatments, typically decreased bacterial genera Enterococcus and Clostridium senus stricto 1. In addition, intake of Chinese bayberry powder and C3G significantly decreased the level of p65 phosphorylation, and up-regulated the expression of intestinal tight junction protein claudin-1 and ZO-1. Chinese bayberry fruit had the effect of alleviating AAD, and C3G was supposed to play the predominant role. The mechanism was indicated to be related with restoring the homeostasis of gut microbiota, inhibiting the level of harmful bacteria and increasing the abundance of beneficial bacteria, down-regulating TNF-α, IL-6, and IL-12 factors to reduce inflammation, restoring intestinal tight junction proteins and reducing intestinal permeability.

Novel application of HS-GC-IMS with PCA for characteristic fingerprints and flavor compound variations in NFC Chinese bayberry (Myrica rubra) juice during storage

The flavor fingerprint of NFC Chinese bayberry (Myrica rubra) juice treated by high hydrostatic pressure (HHP) was developed, and the volatile flavor compound variations formed during storage at 4 °C for 28 days were investigated by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) fingerprinting combined with principal component analysis (PCA). During the bayberry juice storage period, the HS-GC-IMS provided information on the characteristics and intensity of 52 volatile flavor compounds (ten terpenes, fifteen aldehydes, fourteen esters, nine alcohols, three ketones and one furan) and was used to observe the changes in flavor compounds in bayberry juice during storage. The results showed that the contents of (E)-2-hexenal, (Z)-3-hexen-1-ol, linalool and 6-methyl-5-hepten-2-one increased first with prolonged storage time. While the methyl caproate and methyl isobutyrate contents continued to decrease, the 3-pentanone, 2-methylbutanal and 2-methacrolein contents increased gradually. In addition, ethanol (note “alcohol”) and ethyl acetate (note “overripe”) were found to contribute to off-flavor accumulation. The visual plots for HS-GC-IMS and PCA had good consistency, and their combination was excellent for characterizing the aroma characteristics of bayberry juice from different storage periods. This work can provide useful knowledge for understanding the flavors of NFC Chinese bayberry during storage.

Investigation of Potential Use of Soybean Protein Isolate–Chinese Bayberry Tannin Extract Cross-Linked Films in Packaging Applications

The possibility of using commercial bayberry tannin (BT) from a Chinese source as a cross-linker and functional additive to develop soybean protein isolate (SPI)-based films was explored in this study by using the solvent casting method. In particular, the impacts of BT loading on the tensile strength, microstructure, thermal stability, water resistance and antioxidant capacity were fully investigated. The results reveal that SPI incorporated with BT yielded a phenolic–protein hybrid whose relevant films exhibited an improvement in tensile strength of around two times greater compared with native SPI as a result of the formed interactions and covalent cross-links, which could be proven using FTIR spectroscopy. The introduction of BT also led to the compact microstructure of SPI–BT films and enhanced the thermal stability, while the water vapor permeability was reduced compared with the control SPI film, especially at high loading content of tannin. Additionally, the use of BT significantly promoted the antioxidant capacity of the SPI-based films according to DPPH radical scavenging assay results. On this basis, Chinese bayberry tannin is considered a promising natural cross-linker and multifunctional additive that can be dedicated to developing protein-derived films with antioxidant activity for food packaging applications.

Frozen-Phase High-Pressure Destruction Kinetics of Escherichia coli as Influenced by Application Mode, Substrate, and Enrichment Medium.

The synergistic effect of frozen-phase high pressure (HP) on the inactivation of E. coli ATCC 25922 cultures in suspension medium, Chinese bayberry juice (pH 3.0), and carrot juice (pH 6.5) was evaluated. The survivor count of E. coli remained at 3.36 log CFU/mL on a nonselective brain heart infusion (BHIA) medium, while no survivor was detected on a selective violet red bile agar (VRBA) medium after a 5 min hold pressure at 250 MPa in a frozen culture suspension. BHIA was suitable for safe testing of the injured E coli cells after HP treatment in frozen state. Frozen Chinese bayberry juice showed higher sensitivity to HP treatment for its matrix property with high sterilizing efficiency at 170 MPa. Two pulses exhibited a significant inactivation effect in frozen samples compared with one pulse, especially for the Chinese bayberry juice with different pressure levels. The destruction kinetics of HP pulse mode followed the first-order rate kinetics with a Zp value of 267 MPa in frozen carrot juice. Our results evaluated the influenced factors of frozen HP destruction effects, including the medium, substrate, and application mode. The frozen HP destruction kinetics of pulses afford us better understanding of the technology application in the food industry.

First Report of Leaf Spot Caused by Colletotrichum fructicola on Myrica rubra in China.

Myrica rubra is an important fruit tree with high nutritional and economic value, which is widely cultivated in multiple regions of China. In January 2021, an unknown disease which caused leaf spot with approximately 20% (n=100 investigated plants) of incidence was discovered on the leaves of M.rubra in Jiujiang City of Jiangxi Province (29.71° N, 115.97° E). The initial symptoms were small pale brown spots (1 to 2 mm diameter) on the leaves, which gradually expanded into round or irregular dark brown spots with the occurrence of the disease, and the lesion developed necrotic tissues in the center at later stages, eventually leading the leaves to chlorotic and wilted. Ten diseased leaves with typical symptoms were collected and the leaf tissue (5 × 5 mm) at junction of diseased and healthy portion were cut. The surfaces were disinfected with 75% ethanol for 45 s, 1% sodium hypochlorite for 1 min, and rinsed in sterile water for 3 times then transferred to potato dextrose agar (PDA) at 28 ± 1 ℃ for 3 days. Five fungal single isolates with similar morphology were purified from single spores. On PDA medium, the colonies initially appeared white with numerous aerial hyphae, and the center of the colony turned gray at later stages, less sporulation. While on modified czapek-dox medium (Peptone 3g, K2HPO4 1g, MgSO4·7H2O 0.5g, KCl 0.5g, FeSO4 0.01g, Maltose 30g, Agar 15g, Distilled water 1000 mL, pH=7.0), the mycelia of the colony were sparse and produced a large number of small bright orange particles (conidial masses). Conidia were single-celled, transparent, smooth-walled, 1-2 oil globule, cylindrical with slightly blunt rounded ends, 14.45-18.44 × 5.54-6.98 μm (av=16.27 μm × 6.19 μm, n=50) in size. These morphological characteristics of the pathogen were similar to the descriptions of Colletotrichum fructicola (Ruan et al, 2017; Yang et al, 2021). To further confirm the identity of the pathogen, genomic DNA from a representative isolate was extracted with DNA Extraction Kit (Yeasen, Shanghai, China), and the internal transcribed spacer (ITS), glyceraldehyde-3-phosphatedehydrogenase (GAPDH), calmodulin gene (CAL), actin (ACT) and chitin synthase 1 (CHS 1) were amplified by using the primers ITS1/ITS4 (Gardes et al, 1993), GDF/GDR (Templeton et al, 1992), CL1C/CL2C (Weir et al, 2012), ACT-512F/ACT-783R and CHS-79F/CHS-345R (Carbone et al, 1999), respectively. The PCR amplified sequences were submitted to GenBank (GenBank Accession No. ITS, MW740334; GAPDH, MW759805; CAL, MW759804; ACT, MW812384; CHS-1, MW759803) and aligned with GenBank showed 100% identity with C. fructicola (GenBank Accession No. ITS, MT355821.1 (546/546 bp); GAPDH, MT374664.1 (255/255 bp); CAL, MK681354.1 (741/741 bp); ACT, MT364655.1 (262/262 bp); CHS, MT374618.1 (271/271 bp)). Phylogenetic tree using the maximum likelihood methods with Kimura 2-parameter model and combined ITS-ACT-GAPDH-CHS-CAL concatenated sequences, bootstrap nodal support for 1000 replicates in MEGA7.0, revealed that the isolate was assigned to C. fructicola strain (ICMP 18581 and CBS 125397) (Yang et al. 2021) with 98% bootstrap support. Pathogenicities of were tested on fifteen healthy M. rubra plants (five for wounded inoculation, five for nonwounded inoculation, and five for controls) in the orchard. Twenty leaves were marked from each plant, and disinfected the surface with 75% ethanol. Ten μL spore suspension (1.0 × 106 conidia/ml) of each isolate from 7-day-old culture were inoculated on the surface of 20 needle-wounded and 20 nonwounded leaves, respectively. Healthy leaves were inoculated with sterile water as controls by the same method. All inoculated leaves were sprayed with sterile water and covered with plastic film to remained humidification. After 5 days, all the wounded leaves which were inoculated with C. fructicola showed similar symptoms to those observed on the original leaves. Symptoms of nonwounded leaves were milder than the wounded inoculated leaves, while control leaves remained healthy. Finally, the C. fructicola was re-isolated from the inoculated leaves. C. fructicola has been reported on Juglans regia, Peucedanum praeruptorum, Paris polyphylla var. Chinensis in China (Wang et al, 2017; Ma et al, 2020; Zhou et al, 2020). As far as we know, this is the first report of C. fructicola causing leaf spot on M.rubra in China. This result contributes to better understand the pathogens causing diseases of M.rubra in this region of China and develop effective control strategies.

An Anthocyanin-Related Glutathione S-Transferase, MrGST1, Plays an Essential Role in Fruit Coloration in Chinese Bayberry (Morella rubra).

Chinese bayberry (Morella rubra) is a fruit tree economically important in China and accumulates abundant amounts of anthocyanins in fruit as it ripens. Owing to the fact that all anthocyanin containing fruit tissues in Chinese bayberry are edible and anthocyanins can provide various health benefits in human body, the mechanisms underpinning anthocyanin accumulation in this fruit are worthy of investigation. It has been known that in plants anthocyanins are synthesized in the cytoplasmic surface of the endoplasmic reticulum and subsequently transported into the vacuole for storage, and glutathione S-transferases (GSTs) have been verified to be involved in this process. But the characterization and functionalization of the GST counterpart in Chinese bayberry is not available. The GST anthocyanin transporter MrGST1 was discovered to be related with anthocyanin accumulation in fruit from distinct developmental stages of “Biqi,” a staple cultivar that accumulates over 1 mg/g anthocyanins in ripe fruit. The expression of MrGST1 was well associated with anthocyanin accumulation either in fruit collected at six developmental stages or in ripe fruit from 12 cultivars. MrGST1 was found to be responsible for the transport of anthocyanins but not proanthocyanidins when the Arabidopsis tt19 mutant was functionally complemented. Transient ectopic expression of MrGST1 in combination with MrMYB1.1 and MrbHLH1 dramatically boosted pigmentation in Nicotiana tabacum leaves in contrast to MrMYB1.1 and MrbHLH1. The promoter of MrGST1 comprised eight MYB binding sites (MBSs) according to cis-element analysis. Data from yeast one-hybrid assay and dual-luciferase tests demonstrated that MrMYB1.1 exerted considerable transactivation effect on the MrGST1 promoter by recognizing the MBS4, the fourth MBS from the ATG start site. Our results together provided molecular evidence for the contribution of MrGST1 in regulating anthocyanin accumulation in Chinese bayberry fruit.

A comparative metabolomics study of anthocyanins and taste components in Chinese bayberry (Morella rubra) with different flesh colors.

The Chinese bayberry (Morella rubra Sieb. et Zucc.) is grown commercially in China and other Asian countries for its flavorful and appealing fruit. Here, two bayberry varieties differing in both color and flavor, namely, BDK (‘Baidongkui’) and DK (‘Dongkui’), in China were compared. A total of 18 anthocyanins, three proanthocyanidins, and 229 primary metabolites were identified in the pulp of the two varieties; these were analyzed and compared using ultra-performance liquid chromatography-tandem mass spectrometry. The DK pulp showed higher concentrations of all 18 anthocyanins compared with BDK, apart from peonidin-3,5-O-diglucoside which was not detected in BDK and which was responsible for the formation of pink pulp in BDK. Principal component analysis and cluster analysis of the primary metabolites indicated that the two bayberry varieties had distinct metabolite profiles with approximately 37% (85/229) of the primary metabolome being significantly different. Of these, 62 metabolites were down-regulated and 23 metabolites were up-regulated in BDK relative to DK. Our results suggested that the flavor of the BDK fruit was different from DK, which could be explained by the reduced saccharide, organic acid, amino acid, and proanthocyanidin contents. These findings enhance our understanding of the metabolites responsible for color and taste differences in the Chinese bayberry.