通讯机构:
[Xu Zhao; Xiaoyuan Yan] S;State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China<&wdkj&>University of Chinese Academy of Sciences, Beijing, China
期刊:
Chemical Engineering Journal,2023年451:138820 ISSN:1385-8947
通讯作者:
Qiang, Qinping
作者机构:
[Xu, Li; Liu, Bitao; Zhou, Zhi] Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Peoples R China.;[Xu, Li; Liu, Chong; Liu, Bitao; Zhou, Wei; Qiang, Qinping; Peng, Lingling; Ma, Xu; Lang, Tianchun; Xu, Yuqing; Guan, Wei] Chongqing Univ Arts & Sci, Res Inst New Mat Technol, Chongqing 402160, Peoples R China.;[Zhong, Yang] Offshore Oil Engn Co, Tianjin 300461, Peoples R China.;[Nikolaevich, Yakovlev Alexey] TF Gorbachev Kuzbass State Tech Univ, 28, Vesennyaya St, Kemerovo 650000, Russia.
通讯机构:
[Qinping Qiang; Tianchun Lang] R;[Zhi Zhou; Bitao Liu] S;Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160, China<&wdkj&>Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160, China<&wdkj&>School of Chemistry and Materials Science, Hunan Agricultural University, Changsha 410128, China<&wdkj&>School of Chemistry and Materials Science, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160, China
摘要:
Abstract: Gibberellin regulates plant growth, development, and metabolic processes. However, the underlying mechanism of the substantial effect of gibberellin on stem height and secondary metabolites in forage ramie is unclear. Therefore, this study combined transcriptomic and metabolomics analyses to identify the mechanisms regulating growth and secondary metabolite contents in forage ramie following exogenous gibberellin application. Exogenous gibberellin application significantly reduced the lignin content in the leaves but not in the stems. At the same time, gibberellin significantly increased the total flavonoid and chlorogenic acid contents in both the stems and leaves. In addition, 293 differentially expressed genes (DEGs) and 68 differentially expressed metabolites (DEMs) were identified in the leaves. In the stems, 128 DEGs and 41 DEMs were identified. The DEGs PER42, FLS, CYP75A, and PNC1 were up-regulated in the leaves, affecting phenylpropane metabolism. The joint analysis of the DEMs and DEGs revealed that the changes in the DEGs and DEMs in the leaves and stems improved the substrate efficiency in the phenol propane pathway and inhibited lignin synthesis in plants, thus shifting to flavonoid pathway synthesis. In conclusion, gibberellin treatment effectively reduces the lignin content in forage ramie while increasing the flavonoid and chlorogenic acid contents. These findings provide empirical and practical guidance for breeding for forage quality in ramie and the improvement and cultivation control of forage ramie. Keywords: gibberellin; transcriptome; metabolome; lignin; flavonoids
作者机构:
[Hu, Ang] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Peoples R China.;[Wang, Jianjun; Hu, Ang; Meng, Fanfan] Chinese Acad Sci, Nanjing Inst Geog & Limnol, State Key Lab Lake Sci & Environm, Nanjing 210008, Peoples R China.;[Wang, Jianjun; Meng, Fanfan] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Tanentzap, Andrew J.] Trent Univ, Sch Environm, Ecosyst & Global Change Grp, Peterborough, ON K9L 0G2, Canada.;[Tanentzap, Andrew J.] Univ Cambridge, Dept Plant Sci, Ecosyst & Global Change Grp, Cambridge CB2 3EA, England.
通讯机构:
[Jianjun Wang] S;State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academic of Sciences, Nanjing210008, China<&wdkj&>University of Chinese Academy of Sciences, Beijing100049, China
关键词:
dark matter;microbes;dissolved organic matter;global change
摘要:
Abstract: The probiotic role of lactic acid bacteria (LAB) in regulating intestinal microbiota to promote human health has been widely reported. However, the types and quantities of probiotics used in practice are still limited. Therefore, isolating and screening LAB with potential probiotic functions from various habitats has become a hot topic. In this study, 104 strains of LAB were isolated from and identified in traditionally fermented vegetables, fresh milk, healthy infant feces, and other environments. The antibacterial properties—resistance to acid, bile salts, and digestive enzymes—and adhesion ability of the strains were determined, and the biological safety of LAB with better performance was studied. Three LAB with good comprehensive performance were obtained. These bacteria had broad-spectrum antibacterial properties and good acid resistance and adhesion ability. They exhibited some tolerance to pig bile salt, pepsin, and trypsin and showed no hemolysis. They were sensitive to the selected antibiotics, which met the required characteristics and safety evaluation criteria for probiotics. An in vitro fermentation experiment and milk fermentation performance test of Lactobacillus rhamnosus (L. rhamnosus) M3 (1) were carried out to study its effect on the intestinal flora and fermentation performance in patients with inflammatory bowel disease (IBD). Studies have shown that this strain can effectively inhibit the growth of harmful microorganisms and produce a classic, pleasant flavor. It has probiotic potential and is expected to be used as a microecological agent to regulate intestinal flora and promote intestinal health. It can also be used as an auxiliary starter to enhance the probiotic value of fermented milk. Keywords: lactic acid bacteria; probiotics; antibacterial; safety evaluation; flavor; screening
期刊:
Journal of Plant Growth Regulation,2023年42(7):4095-4105 ISSN:0721-7595
通讯作者:
Meng Li
作者机构:
[Li, Meng; Li, Jian; Ji, Xiaomin; Mao, Rongjie] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Cao, Fuxiang] Hunan Agr Univ, Coll Hort & Landscape, Changsha 410004, Peoples R China.
通讯机构:
[Meng Li] C;College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China
关键词:
CCoAOMT;Lignin;Poplar (Populus tomentosa);Arabidopsis thaliana;Dove tree (Davidia involucrata Baill.)
摘要:
Rapid lignification and high lignin accumulation occur in the endocarps of the dove tree (Davidia involucrata) during a short developmental phase. Through transcriptome analysis, we identified a gene named DiCCoAOMT1 that plays a vital role in the rapid lignification process. The expression profile of the DiCCoAOMT1 gene was endocarp-specific, and its encoding product showed strong O-methyltransferase activity in vitro. Here, we overexpressed the DiCCoAOMT1 gene in both Arabidopsis and poplar (Populus tomentosa) to verify its function of lignin biosynthesis and accumulation. Increased plant height and lengthened pods arose in transgenic Arabidopsis lines, while elongated petioles were observed in transgenic poplar lines. Moreover, the stems exhibited enlarged xylem area, reduced pith area, and more compact cell architecture in both transgenic Arabidopsis and poplar lines. The lignin content was elevated by 26% and 20% on average in the stems of transgenic Arabidopsis and poplar lines, respectively. Furthermore, the lignin composition was altered in the transgenic lines indicated by the elevated S/G ratio. Taken together, we proposed that overexpressing the DiCCoAOMT1 gene can effectively increase lignin biosynthesis and change lignin monomer composition in both herb and woody plants. The endocarp-specific expression pattern of the DiCCoAOMT1 gene is assumed to be a key point to form the highly lignified structure in a short period, thus causing the long-period dormancy of Davidia seeds.
摘要:
BACKGROUND: Intestinal senescence is associated with several aging-related diseases. l-Theanine (LTA) has demonstrated strong potential as an antioxidant and antisenescence agent. This study investigated the regulatory effect of LTA on cellular senescence using an in vitro model of d-galactose (D-Gal)-induced senescence in the rat epithelial cell line, intestinal epithelioid cell-6 (IEC-6). RESULTS: Treatment of IEC-6 cells with 40 mg/mL D-Gal for 48 h resulted in the successful development of the senescent cell model. Compared with D-Gal alone, both LTA preventive and delayed intervention increased cell viability and the ratio of JC-1 monomers to aggregates, increased the antioxidant capacity, and decreased the advanced glycation end product (AGE) levels and the overall number of senescent cells. Preventive and delayed intervention with 1000 mu M LTA alleviated the D-Gal-induced cell cycle arrest by regulating p38, p53, CDK4, and CDK6 expression at the mRNA and protein levels, and further induced CycD1 proteins. Moreover, LTA preventive intervention reduced apoptosis to a greater degree than delayed intervention by upregulating the expression of the receptors of AGEs, Bax, Bcl-2, and NF-kappa B at the mRNA and protein levels. CONCLUSION: Our findings indicate that LTA intervention could attenuate senescence in IEC-6 cells by regulating the cell cycle and inhibiting apoptosis. (c) 2023 Society of Chemical Industry.
摘要:
Electrontransfer (ET) is the essence of most biogeochemical processesrelated to element cycling and contaminant attenuation, whereas ETbetween different minerals and the controlling mechanism remain elusive.Here, we used surface-associated Fe-(II) as a proxy to explore ET betweenreduced nontronite NAu-2 (rNAu-2) and Fe (hydr)-oxides in their coexistingsystems. Results showed that ET could occur from rNAu-2 to ferrihydritebut not to goethite, and the ET amount was determined by the numberof reactive sites and the reduction potential difference between rNAu-2and ferrihydrite. ET proceeded mainly through the mineral-mineralinterface, with a negligible contribution of dissolved Fe2+/Fe3+. Control experiments by adding K+ andincreasing salinity together with characterizations by X-ray diffraction,scanning electron microscopy/energy-dispersive spectrometry, and atomicforce microscopy suggested that ferrihydrite nanoparticles insertedthe interlayer space in rNAu-2 where structural Fe-(II) in rNAu-2 transferredelectrons mainly through the basal plane to ferrihydrite. This studyimplicates the occurrence of ET between different redox-active mineralsthrough the mineral-mineral interface. As minerals at differentreduction potentials often coexist in soils/sediments, the mineral-mineralET may play an important role in subsurface biogeochemical processes. Electron transfer from Fe-(II)-bearingclay minerals to Fe(hydr)-oxides proceeds mainly through the mineral-mineral interface,with the interior structural Fe-(II) and expandable interlayer spacein clay minerals serving as the major electron reservoir and reactionsite, respectively.
关键词:
Small berry pomace;Nutrition;Phytochemical;Antioxidant activity;Metabolomics
摘要:
Small berry pomaces (SBPs) are poorly utilized as an inexpensive source of bioactive compounds. This study investigated the impact of compounding treatment on nutritional and antioxidant characteristics of combined SBPs, in comparison with single SBP. The results showed that the amounts of protein, minerals, dietary fiber (DF) and anthocyanidins were significantly (p < 0.05) higher in combined SBPs than in combined fruits. Moreover, the combined SBPs were characterized by an elevated abundance of minerals and anthocyanidins (6 kinds, and 5 kinds, respectively), substantiating the effectiveness of compounding treatment on SBP nutrition. A total of 776 secondary phytochemicals were detected in combined SBPs by a widely targeted metabolomics approach. Each SBP contained approximately 100 kinds of unique natural antioxidants. Furthermore, the combined SBPs group had the highest antioxidant activity compared with single SBP. Meanwhile, the antioxidant activities determined in combined SBPs were higher than arithmetic mean value of single SBP. The synergism and interaction of active components in different sources of SBPs play vital role in the high antioxidant capacity of combined SBPs. All the results provide reference for the comprehensive development and utilization of fruit residues. The SBPs should be highly prized for their substantial amount of nutritional and bioactive constituents, including protein, DF, essential minerals and secondary metabolites. These secondary metabolites are positively associated with antioxidant benefits. The present study summarizes the knowledge about bioactive compounds and antioxidant activities of combined SBPs group and discusses the relevant mechanisms. A conclusion can be educed that combined process is an effective way to improve properties of the pomaces.
摘要:
L. monocytogenes (L. m) is one of the most common causes of foodborne diseases. To enable timely monitoring of L. m contamination, a highly efficient and sensitive electrochemical biosensor was developed for the precise determination of L.m. The biosensor was prepared by sequentially modifying glassy carbon electrode (GCE) with silicon methylene blue (Si@MB), gold nanoparticles (AuNPs) and aptamer (Apt). Differential pulse voltammetry (DPV) was used to quantify L.m. This biosensor could be finished in 1.5 h, which significantly reduced the detection time. The resulting electrochemical biosensor achieved good linear (102-107 CFU/mL) and excellent detection limit of 2.6 CFU/mL. Moreover, the novel strategy has been successfully applied to actual samples, with the recoveries ranging from 84.7% to116.0% in lettuce and from 80.0% to 110% in fresh-cut fruit. This biosensor shows great potential application in monitoring bacterial food contamination and infectious diseases.
摘要:
Abstract: Heat stress (HS) has become one of the major abiotic stresses that severely constrain rice growth. Abscisic acid (ABA) plays an important role in plant development and stress response. However, the effect of different concentrations of exogenous ABA on HS tolerance in rice still needs to be further elucidated. Here, we found that high concentrations of exogenous ABA increased HS damage in seedlings, whereas 10−12 M ABA treatment increased fresh and dry weight under HS relative to mock seedlings. Our further data showed that, in response to HS, 10−5 M, ABA-treated seedlings exhibited a lower chlorophyll content, as well as transcript levels of chlorophyll biosynthesis and antioxidant genes, and increased the accumulation of reactive oxygen species (ROS). In addition, the transcript abundance of some heat-, defense-, and ABA-related genes was downregulated on 10−5 M ABA-treated seedlings under HS. In conclusion, high concentrations of exogenous ABA reduced the HS tolerance of rice seedlings, and this negative effect could be achieved by regulating the accumulation of ROS, chlorophyll biosynthesis, and the transcription levels of key genes in seedlings under HS. Keywords: rice (Oryza sativa L.); seedling; ABA; heat stress; reactive oxygen species
通讯机构:
[Wang, Z ; Yang, HL ] H;Hunan Agr Univ, Coll Environm & Ecol, Changsha 410128, Hunan, Peoples R China.;Hunan Prov Key Lab Rural Ecosyst Hlth Dongting La, Changsha 410128, Hunan, Peoples R China.;Hunan Normal Univ, Coll Life Sci, Changsha 410006, Hunan, Peoples R China.
关键词:
Cadmium and lead;Combined exposure;Spiders;Silk production;Web-weaving behavior
摘要:
The combined exposure of multiple metals imposes a substantial burden on the ecophysiological functions in organisms; however, the precise mechanism(s) remains largely unknown. Here, adult female A. ventricosus were exposed to single and combined exposure to cadmium (Cd) and lead (Pb) through the food chain. The aim was to explore the combined toxicity of these metals on silk production and web-weaving behavior at physiological, cellular morphological, and transcriptomic levels. The Cd and Pb combined exposure significantly inhibited the ability of silk production and web-weaving, including reduced silk fiber weight and diameter of single strands, lowered weaving position, induced nocturnal weaving, and increased instances of no-web, and showed a dose-response relationship on the Cd and Pb bioaccumulation. Concurrently, severe oxidative stress and degenerative changes in cells were observed. In addition, the combined pollution of Cd and Pb demonstrated synergistic effects, influenced by variations in concentration, on the enrichment of metals, inhibition of silk weight, oxidative damage, and cellular degeneration. At the transcriptome level, the upregulated ampullate spidroin genes and downregulated amino acid anabolic genes, upregulated Far genes and downregulated cytoskeleton-related TUBA genes, and overexpressed AChE and Glu genes may tend to present promising potential as biomarkers for silk protein synthesis, cellular degeneration, and neurotransmitter induction. This study offers an enormous capability for a comprehensive understanding of the eco-toxicological effects and mechanisms of multiheavy metals pollution.
摘要:
The retention and fate of Roxarsone (ROX) onto typical reactive soil minerals were crucial for evaluating its potential environmental risk. However, the behavior and molecular-level reaction mechanism of ROX and its substituents with iron (hydr)oxides remains unclear. Herein, the binding behavior of ROX on ferrihydrite (Fh) was investigated through batch ex-periments and in-situ ATR-FTIR techniques. Our results demonstrated that Fh is an effective geo-sorbent for the retention of ROX. The pseudo-second-order kinetic and the Langmuir model successfully described the sorption process. The driving force for the binding of ROX on Fh was ascribed to the chemical adsorption, and the rate-limiting step is simultaneously dominated by intraparticle and film diffusion. Isotherms results revealed that the sorption of ROX onto Fh appeared in uniformly distributed monolayer adsorption sites. The two-dimensional correlation spectroscopy and XPS results implied that the nitro, hydroxyl, and arsenate moiety of ROX molecules have participated in binding ROX onto Fh, signifying that the predominated mechanisms were attributed to the hydrogen bonding and surface com-plexation. Our results can help to better understand the ROX-mineral interactions at the molecular level and lay the foundation for exploring the degradation, transformation, and remediation technologies of ROX and structural analog pollutants in the environment.(c) 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
作者机构:
[Song, Fengmei; Tang, Xiaomin; Cao, Yi; Zhao, Weichao] Univ South China, Sch Publ Hlth, Hengyang Med Sch, Hunan Prov Key Lab Typ Environm Pollut & Hlth Haza, Hengyang 421001, Peoples R China.;[Huang, Chaobo] Nanjing Forestry Univ NFU, Coll Chem Engn, Nanjing 210037, Peoples R China.;[Dai, Xuyan] Hunan Agr Univ, Econ Coll, Changsha 410128, Peoples R China.
通讯机构:
[Yi Cao] H;Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
摘要:
Abstract: Simple Summary Nano-ZnO has emerged as a popular study subject for the addition of trace elements in the manufacture of animal feed. However, the current research has not studied how different particle sizes of nano-ZnO affect the broiler. In the current study, we studied the impact of two different nano-ZnO particle sizes in broilers. Finally, it was discovered that ZnO nanoparticles could enhance broiler growth performance, promote the development of immune organs, enhance generalized immunity, have some anti-inflammatory effects, and enrich beneficial intestinal bacteria. The effects of the above improvements were negatively correlated with the nanoparticles’ particle sizes. Abstract The effects of dietary supplementation with two particle sizes of nano zinc oxide (ZnO) on growth performance, immune function, intestinal morphology, and the gut microbiome were determined in a 42-day broiler chicken feeding experiment. A total of 75 one-day-old Arbor Acres broilers were randomized and divided into three groups with five replicates of five chicks each, including the conventional ZnO group (NC), the nano-ZnO group with an average particle size of 82 nm (ZNPL), and the nano-ZnO group with an average particle size of 21 nm (ZNPS). Each group was supplemented with 40 mg/kg of ZnO or nano-ZnO. Our results revealed that birds in the ZNPS group had a higher average daily gain and a lower feed-to-gain ratio than those in the NC group. ZNPS significantly increased the thymus index and spleen index, as well as the levels of serum metallothionein (MT), superoxide dismutase (SOD), and lysozyme (LZM). The ZNPS treatments reduced interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α) levels and increased IL-2 and interferon (IFN)-γ levels compared to that in the NC group. Additionally, compared with the birds in the NC group, those in the nano-ZnO group had a higher villus height to crypt depth ratio of the duodenum, jejunum, and ileum. Bacteroides increased in the ZNPS group at the genus level. Further, unidentified_Lachnospiraceae, Blautia, Lachnoclostridium, unidentified_Erysipelotrichaceae, and Intestinimonas were significantly increased in the ZNPL group. In conclusion, nano-ZnO improved the growth performance, promoted the development of immune organs, increased nonspecific immunity, improved the villus height to crypt depth ratio of the small intestine, and enriched the abundance of beneficial bacteria. Notably, the smaller particle size (21 nm) of nano-ZnO exhibited a more potent effect. Keywords: broiler chickens; nano-ZnO; growth performance; immune function; gut microbiome
摘要:
RNA N6-methyladenosine (m(6)A ) modification is one of the principal post-transcriptional modifications and plays a dynamic role in testicular development and spermatogenesis. However, the role of m(6)A in porcine testis is understudied. Here, we performed a comprehensive analysis of the m(6)A transcriptome-wide profile in Shaziling pig testes at birth, puberty, and maturity. We analyzed the total transcriptome m(6)A profile and found that the m(6)A patterns were highly distinct in terms of the modification of the transcriptomes during porcine testis development. We found that key m(6)A methylated genes (AURKC, OVOL, SOX8, ACVR2A, and SPATA46) were highly enriched during spermatogenesis and identified in spermatogenesis-related KEGG pathways, including Wnt, cAMP, mTOR, AMPK, PI3K-Akt, and spliceosome. Our findings indicated that m(6)A methylations are involved in the complex yet well-organized post-transcriptional regulation of porcine testicular development and spermatogenesis. We found that the m(6)A eraser ALKBH5 negatively regulated the proliferation of immature porcine Sertoli cells. Furthermore, we proposed a novel mechanism of m(6)A modification during testicular development: ALKBH5 regulated the RNA methylation level and gene expression of SOX9 mRNA. In addition to serving as a potential target for improving boar reproduction, our findings contributed to the further understanding of the regulation of m(6)A modifications in male reproduction.
通讯机构:
[Dongling Zhang] D;[Xiaoying Yu] C;[Yanlin Li] I;Department of Horticulture, University of Georgia, Athens, USA<&wdkj&>College of Horticulture, Hunan Agricultural University, Changsha, China<&wdkj&>Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, China<&wdkj&>Hunan Mid-subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, China<&wdkj&>Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China<&wdkj&>College of Horticulture, Hunan Agricultural University, Changsha, China<&wdkj&>Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding, Ministry of Education, Changsha, China<&wdkj&>Hunan Mid-subtropical Quality Plant Breeding and Utilization Engineering Technology Research Center, Changsha, China
关键词:
Leaf colour;Pigmentation;Anthocyanin;Synthesis pathway;Loropetalum chinense var. Rubrum
摘要:
Loropetalum chinense var. rubrum (L. chinense var. rubrum) is a precious, coloured-leaf native ornamental plant in the Hunan Province. We found an L. chinense var. rubrum tree with three different leaf colours: GL (green leaf), ML (mosaic leaf), and PL (purple leaf). The mechanism of leaf coloration in this plant is still unclear. Therefore, this study aimed to identify the metabolites and genes involved in determining the colour composition of L. chinense var. rubrum leaves, using phenotypic/anatomic observations, pigment content detection, and comparative metabolomics and transcriptomics. We observed that the mesophyll cells in PL were purple, while those in GL were green and those in ML were a mix of purple-green. The contents of chlorophyll a, b, carotenoids, and total chlorophyll in PL and ML were significantly lower than those in GL. While the anthocyanin content in PL and ML was significantly higher than that in GL. The metabolomics results showed the differences in the content of cyanidin 3-O-glucoside, delphinidin 3-O-glucoside, cyanidin 3,5-O-diglucoside, pelargonidin, and petunidin 3,5-diglucoside in ML, GL, and PL were significant. Considering that the change trend of anthocyanin content change was consistent with the leaf colour difference, we speculated that these compounds might influence the colour of L. chinense var. rubrum leaves. Using transcriptomics, we finally identified nine differentially expressed structural genes (one ANR (ANR1217); four CYP75As (CYP75A1815, CYP75A2846, CYP75A2909, and CYP75A1716); four UFGTs (UFGT1876, UFGT1649, UFGT1839, and UFGT3273) and nine transcription factors (two MYBs (MYB1057 and MYB1211), one MADS-box (MADS1235), two AP2-likes (AP2-like1779 and AP2-like2234), one bZIP (bZIP3720), two WD40s (WD2173 and WD1867) and one bHLH (bHLH1631) that might be related to flavonoid biosynthesis and then impacted the appearance of colour in L. chinense var. rubrum leaves. This study revealed potential molecular mechanisms associated with leaf coloration in L. chinense var. rubrum by analyzing differential metabolites and genes related to the anthocyanin biosynthesis pathway. It also provided a reference for research on leaf colour variation in other ornamental plants.
摘要:
Allelopathy has been considered a good explanation for the successful invasion of some invasive plants. However, the real latitudinal and longitudinal allelopathic effects on native species have rarely been documented since many exotics have spread widely. We conducted a Petri dish experiment to determine the latitudinal and longitudinal allelopathic patterns of an invasive alligator weed (Alternanthera philoxeroides) on a common crop (Lactuca sativa) in China, and find what determines the allelopathic intensity. The results showed that the allelopathic effects of A. philoxeroides increased with the latitude while decreased with the longitude. This indicated that A. philoxeroides used its allelopathy to gain competitive advantages more in its recent invaded communities than that in its early invaded ones as A. philoxeroides is expanding from southeast China to northwest China. Furthermore, we found that the allelopathic intensity of A. philoxeroide was negatively correlated to the leaf contents of soluble carbohydrate (SC), carbon (C) and nitrogen (N), but that was positively correlated to the leaf contents of soluble protein (SP), free amino acids (FAA), plant polyphenol (PP), phosphorus (P) and potassium (K). These results suggested that the allelopathic intensity of A. philoxeroide was more determined by the limited P and K nutrients as well as the intermediate allelochemicals (SP, FAA, PP) rather than the unlimited C, N and SC. Thus, we can speculate that the negative or positive effects of plant aqueous extracts are a function of not only the extract concentrations but also the trade-offs between inhibition and promotion of all components in the extracts. Then we could reduce the allelopathic effects of A. philoxeroide by controlling the component contents in the plant tissues, by fertilization or other managements, especially in the plant recent invaded communities.
摘要:
Innate immunity is the first line of defense against viral pathogens. Retinoic Acid-Inducible Gene 1 (RIG-I) is a pattern recognition receptor that recognizes virus-associated double-stranded RNA and initiates the interferon responses. Besides signal transduction, RIG-I exerts direct antiviral functions to displace viral proteins on dsRNA via its Helicase activity. Nevertheless, this effector-like activity of RIG-I against herpesviruses remains largely unexplored. It has been previously reported that herpesviruses deamidate RIG-I, resulting in the abolishment of its Helicase activity and signal transduction. In this study, we discovered that RIG-I possessed signaling-independent antiviral activities against murine gamma herpesviruses 68 (γHV68, murid herpesvirus 4). Importantly, a Helicase-dead mutant of RIG-I (K270A) demonstrated comparable inhibition on herpesviruses lytic replication, indicating that this antiviral activity is Helicase-independent. Mechanistically, RIG-I bound the Replication and Transcription Activator (RTA) and diminished its nuclear localization to repress viral transcription. We further demonstrated that RIG-I blocked the nuclear translocation of ORF21 (Thymidine Kinase), ORF75c (vGAT), both of which form a nuclear complex with RTA and RNA polymerase II (Pol II) to facilitate viral transcription. Moreover, RIG-I retained ORF59 (DNA processivity factor) in the cytoplasm to repress viral DNA replication. Altogether, we illuminated a previously unidentified, Helicase-independent effector-like function of RIG-I against γHV68, representing an exquisite host strategy to counteract viral manipulations on innate immune signaling. IMPORTANCE: Retinoic acid-inducible gene I (RIG-I), a member of DExD/H box RNA helicase family, functions as a key pattern recognition receptor (PRR) responsible for the detection of intracellular double-stranded RNA (dsRNA) from virus-infected cells and induction of type I interferon (IFN) responses. Nevertheless, our understanding of the helicase-independent effector-like activity of RIG-I against virus infection, especially herpesvirus infection, remains largely unknown. Herein, by deploying murine gamma herpesviruses 68 (γHV68) as a model system, we demonstrated that RIG-I possessed an interferon and helicase-independent antiviral activity against γHV68 via blocking the nuclear trafficking of viral proteins, which concomitantly repressed the viral early transcription and genome replication thereof. Our work illuminates a previously unidentified antiviral strategy of RIG-I against herpesvirus infection.