Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in trees.One possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced leaves.However,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly documented.An experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence period.The aim was to identify potential nutritional consequences of droughts for trees.Monitoring nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(i.e.resorption efficiency),thus reducing the K reserve in trees for the next growing season.This result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study site.Reduced foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also observed.In addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree nutrition.The calcium(Ca)negative resorption decreased,with no apparent consequence in our study site.Our results show that nutrient exchanges in the canopy and the partitioning of the green leaf pool can be modified by drought events,and may have consequences on tree nutrition.

Influence of soaking Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China

To investigate the effects of drinking the soaking of Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China.It has been reported that longevity is closely related to metabolism and the gut microbiota.The 16S rRNA sequencing and liquid chromatography-mass spectrometry(LC-MS)were used to analysis fecal samples and explore the factors affecting longevity in the region.Interestingly,we discovered,that elderly individuals who had been drinking the soaking of M.domeri(Bois)Chev.leaves for a long time exhibited higher diversity of the gut microbiota than without drinking the soaking,notably.The proportions of Ruminococcaceae and Prevotella were decreased in those who did not drink this soaking.In addition,a total of 106 metabolites were characterized,and the people of long-lived people(>90 years old)and elderly people(<90 years old)who drinking soaking of M.domeri(Bois)Chev.leaves significantly altered the gut microbiota and upregulated levels of haplopine,farnesol,genipic acid,momordicinin,2-hydroxyestrone,hydroxyphenyllactic acid,caffeic acid,sophoraflavanone B,and soyasaponin I.We preliminarily determined that M.domeri(Bois)Chev.leaves consumption may be an important factor affecting longevity in this area.

Changes in Polyphenols and Antioxidant Activities of Yingshan Yunwu Tea during Digestion in Vitro

[Objectives]To explore the change rule of polyphenol content and antioxidant activity of coarse old leaves of Yingshan Yunwu Tea in the process of human digestion.[Methods]The coarse and old leaves of Yunwu tea in Yingshan,Huanggang,Hubei Province were selected as the research object,and their digestion in vitro was simulated.The total polyphenol content was determined by Folin-phenol reagent colorimetric method,and the DPPH radical scavenging activity and total antioxidant activity were determined.[Results]After simulated gastrointestinal digestion in vitro,the polyphenol content and antioxidant activity of coarse old leaf tea soup showed a downward trend.After gastrointestinal digestion,the polyphenol content in tea infusion separately decreased by 31.8%and 8.5%;the scavenging rate of DPPH free radical was 97%before digestion,decreased to 92%after gastric digestion and 65%after intestinal digestion,which decreased by 5%and 27%,respectively;after gastrointestinal digestion,the total antioxidant capacity of tea soup decreased by 4.7%and 3.1%,respectively.[Conclusions]This study provided a reference for the development and application of coarse old leaves of Yingshan Yunwu tea,and provided a reference for the nutritional value evaluation and comprehensive utilization of coarse old leaves,so as to make the best use of coarse tea leaves and reduce the waste of resources.

The Protective Effects of Flavonoids from Scutellaria Baicalensis Georgi Stems and Leaves on Oligodendrocyte Damage Induced by Aβ1-42

Aim: This study aimed to investigate the protective effects of flavonoids from the stem and leaves of Scutellaria baicalensis Georgi (SSFs) against Aβ1-42-induced oligodendrocytes (OL) damage. Methods: Immunofluorescence was used for the detection of myelin-associated glycoprotein (MAG), a characteristic protein of rat oligodendrocytes (OLN-93 cells). To evaluate the potential protective effects of SSFs on OLN-93 cells injured by Aβ1-42, an injury model was established by subjecting OLN-93 cells to Aβ1-42 exposed. Cell morphology was examined using an inverted microscope, while cell viability was assessed using the colorimetric method of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Additionally, lactate dehydrogenase (LDH) was measured using the pyruvic acid reduction assay. The Ginkgo biloba leaf extract (GBE) injection was used as a positive control. Results: A total of >95% of the MAG immunofluorescence-positive cells were identified as oligodendrocytes. Gradually increasing concentrations of SSFs impaired the cells, and the maximum nondetrimental dose for OLN-93 cells was 75 mg/L. This study assessed the effects of SSFs on OLN-93 cells damaged by Aβ1-42. The results indicated that SSFs significantly improved OLN-93 cell morphological abnormal changes, increased the OLN-93 cell survival rate, and reduced LDH release. Conclusion: SSFs can alleviate Aβ1-42-induced damage of OL.

乘船环游世界

很多人都有环游世界的梦想。有一家公司推出了乘坐游轮环游世界的方案,全程需要三年时间。主题语境:环球旅行篇幅:364词建议用时:7分钟1 Have you ever dreamed of giving it all up, leaving it all behind and hitting the road to escape all your responsibilities? It sounds good, doesn't it? But it also sounds expensive. Now a cruise company is launching a 3-year, 210,000-kilometer, escape-your-dailylife cruise for a relatively affordable $30,000 per person per year.

快逃!

One day in November 1647,Jacob Armitage hurried through the New Forest to the house of Arnwood.“You must leave this house immediately,”he said to Edward Beverley.“Come with me to pack your things.You must come to my home and stay there.”“But why,Jacob?”Edward asked the old man“.Why?”

Isotherm, Kinetic and Thermodynamic Studies for the Sorption of Mercury (II) onto Activated Carbon from <i>Rosmarinus officinalis</i>Leaves

The present work deals with the equilibrium adsorption of Hg(II) onto carbonized Rosmarinus officinalis leaves (ACROL) as a new adsorbent from aqueous solution and it has been investigated. ACROL samples were prepared by physical carbonization at 773 K for 1 h. Titration method was used to determine the concentration of Hg(II) before and after adsorption onto ACROL by ethylenediaminetetraacetic acid, EDTA, as chelating agent. Batch equilibrium studies were carried out under different experimental conditions such as Hg(II) concentration and temperature. The relationship between the amount of Hg(II) onto ACROL can be described using four tow-parameter isotherm models. The equilibrium sorption data were analyzed using Freundlich, Langmuir, Dubinin-Radushkevich (DRK) and Temkin isotherms. The experimental results were found to fit the Langmuir isotherm model with a monolayer adsorption capacity of 588.2 mg/g at 318 K, while they were found to fit the Freundlich isotherm model at 298 K. The KL was decreased with increasing temperature, indicating a bond strength between Hg(II) and ACROL decreased with increasing temperature and sorption is exothermic. From DRK isotherm, free energy, E, was higher than 31 kJ/mol suggesting the Hg(II) adsorption onto ACROL chemical sorption. The thermodynamic studies revealed that the process is spontaneous nature of Hg(II) adsorption by ACROL and exothermic. The findings from this research show that ACROL has capability to remove Hg(II) from aqueous solutions.

Process Optimization of Extraction Technique of Polysaccharide from Leaves of Dendrobium officinale

[Objectives] To optimize the extraction process of polysaccharides from leaves of Dendrobium officinale. [Methods]The polysaccharides from D. officinale were extracted by internal boiling method. The extraction rate of polysaccharides from D. officinale was studied.Based on the single factor experiment,the L_9( 3~3) orthogonal experiment was designed to optimize the extraction process of polysaccharides from D. officinale. [Results]The optimum process for extracting polysaccharides from D. officinale by internal boiling method was as follows:1. 00 g of D. officinale powder was desorbed with 6. 0 mL of 20% ethanol for 20 min,35. 0 mL of 90℃ water was rapidly added,and the extraction time was 5 min. [Conclusions] Under this condition,the extraction rate of polysaccharides from D. officinale was 12. 31%,which was 3. 75 percentage points higher than that of traditional reflux extraction.

Physicians Leaving an Academic Position for Private Practice

Introduction When interviewing a medical resident for a potential fellowship in Cardiovascular medicine,the majority of candidates indicate an interest in academic cardiology.However,few opt for an academic career and many decide during fellowship that private practice is best for them.I have no problem with that decision.The focus of this manuscript in on those who opt for an academic career and for several reasons decide,after a few years,to leave the academic program and often leave gaping holes in the multiple aspects of the program,that require attention of the chief of cardiology.

Preventing of Early School Leaving: Sport as Protective Factor

The study aims to highlight the contribution of sport as a tool for preventing early school leaving and developing psychophysical well-being.School,territory and sports association can,with appropriate institutional partnership actions,implement training interventions in this sense.Through an analysis of the scientific literature we want to highlight the important value of sports practice especially in school age.Organized sports activities contribute to the development of skills related to socio-relational well-being.Full awareness of one’s own cognitive and social skills allows improving self-perception.Sport,therefore,becomes a tool for preventing and contrasting early school leaving,a real protective factor that limits the decrease in motivation to school attendance and favors school performance.

Applicability of the Method of Linear Dimensions to Estimate Leaf Area in Improved Genotypes of Coffea arabica and Coffea canephora

There are different methods to determinate leaf area in coffee plants;however, methodologies that allow measurement of leaf area accurately and in nondestructive ways are very important, as they are less economically costly and enable measurements on the same leaf over time, making it possible to describe accurate patterns of growth. The objective of this study was to investigate the applicability of the method to estimate leaf area using linear dimensions of leaves for improved genotypes of Coffea arabica L. and Coffea canephora Pierre ex A. Froehner. The experiment was conducted in two separated competition fields, each one following factorial schemes 10 × 2, with 10 genotypes and 2 methods to obtain the leaf area: measuring linear dimensions, and using equation model (estimated leaf area) and leaf area integrator (real leaf area). The genotypes for both Coffea arabica L. and Coffea canephora Pierre ex A. Froehner have different leaf areas, making it possible to discriminate groups of genotypes for both species using the size of their leaves as classification criteria. Even with the differences between genotypes, the pattern of leaf shape remains similar, confirming the applicability of the method to estimate leaf area using linear dimensions of leaves for improved genotypes, such as the model proposed by Barros, without the occurrence of loss of accuracy for the improved genotypes, for both Arabica and Conilon coffee, studied in this experiment.

The Great British Bake off

The most popular TV programme in the UK was a reality show called The Great British Bake Off.Each week,ordinary people compete to make the best cakes and bread within a time limit.The competition takes place in a very large tent in a big garden.There are two judges,and each week they choose a "Star Baker"(the best baker).They also choose one person who must leave the competition.At the end of ten weeks there is one winner.

Leaving a Legacy

APRIL 27, 1994 is a day South Africans will never forget. It marked the first democratic elections, historically ending more than 300 years of colonial and white minority rule, It also heralded the election of Nelson Mandela. an icon in the country＇s pursuit of freedom, as South Africa＇s president.

Antioxidant,antimicrobial,and α-glucosidase inhibitory activities of saponin extracts from walnut(Juglans regia L.) leaves

Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.

Mutations in the miRNA165/166 binding site of the HB2 gene result in pleiotropic effects on morphological traits in wheat

Leaf,spike,stem,and root morphologies are key factors that determine crop growth,development,and productivity.Multiple genes that control these morphological traits have been identified in Arabidopsis,rice,maize,and other plant species.However,little is known about the genomic regions and genes associated with morphological traits in wheat.Here,we identified the ethyl methanesulfonate-derived mutant wheat line M133 that displays multiple morphological changes that include upward-curled leaves,paired spikelets,dwarfism,and delayed heading.Using bulked segregant RNA sequencing(BSR-seq)and a high-resolution genetic map,we identified TraesCS1D02G155200(HBD2)as a potential candidate gene.HB-D2 encodes a class III homeodomain-leucine zipper(HD-ZIP III)transcription factor,and the mutation was located in the miRNA165/166 complementary site,resulting in a resistant allele designated rHb-D2.The relative expression of rHb2 in the mutant plants was significantly higher(P<0.01)than in plants homozygous for the WT allele.Independent resistant mutations that disrupt the miRNA165/166 complementary sites in the A-(rHb-A2)and B-genome(rHb-B2)homoeologs showed similar phenotypic alterations,but the relative intensity of the effects was different.Transgenic plants expressing rHb-D2 gene driven by the maize UBIQUITIN(UBI)promoter showed similar phenotypes to the rHb-D2 mutant.These results confirmed that HB-D2 is the causal gene responsible for the mutant phenotypes.Finally,a survey of 1397 wheat accessions showed that the complementary sites for miRNA165/166 in all three HB2 homoeologs are highly conserved.Our results suggest that HB2 plays an important role in regulating growth and development in wheat.

VG,encoding a thylakoid formation protein,regulates the formation of variegated leaves in tomato

Leaf-color mutations have been studied extensively in plants.However,to better understand the complex mechanisms underlying the formation of leaf color,it is essential to continue discover novel genes involved in the process of leaf color development.In this study,we identified a variegated-leaf(vg)mutant in tomato that exhibited defective phenotypes in thylakoids and photosynthesis.To clone the vg locus,an F2population was constructed from the cross between the vg mutant(Solanum lycopersicum)and the wild tomato LA1589(S.pimpinellifolium).Using the map-based cloning approach,the vg locus was mapped on chromosome 7 and narrowed down to a 128 kb region that contained 21 open reading frames(ORFs).The expression levels of ORF9,ORF10,and ORF13 were significantly lower in vg than in the wild-type plants,while the ORF11 transcript level was elevated in vg.We then mutagenized ORF9,ORF10,and ORF13 by the CRISPR/Cas9 system in the wild-type tomato background and found that only the ORF10 mutation reproduced the phenotype of variegated leaves,indicating that ORF10 represents VG and its down-regulated expression was responsible for the variegated leaf phenotype.ORF10 encodes a thylakoid formation protein and its mutant lines showed reduced levels of chlorophyll synthesis and photosynthesis.Taken together,these results suggest that VG is necessary for chloroplast development,chlorophyll synthesis,and photosynthesis in tomato.

Tomato LysM receptor kinase 4 mediates chitin-elicited fungal resistance in both leaves and fruit

Fungal infection is a major cause of crop and fruit losses.Recognition of chitin,a component of fungal cell walls,endows plants with enhanced fungal resistance.Here,we found that mutation of tomato LysM receptor kinase 4(SlLYK4)and chitin elicitor receptor kinase 1(SlCERK1)impaired chitin-induced immune responses in tomato leaves.Compared with the wild type,sllyk4 and slcerk1 mutant leaves were more susceptible to Botrytis cinerea(gray mold).SlLYK4 extracellular domain showed strong binding affinity to chitin,and the binding of SlLYK4 induced SlLYK4-SlCERK1 association.Remarkably,qRT–PCR analysis indicated that SlLYK4 was highly expressed in tomato fruit,andβ-GLUCURONIDASE(GUS)expression driven by the SlLYK4 promoter was observed in tomato fruit.Furthermore,SlLYK4 overexpression enhanced disease resistance not only in leaves but also in fruit.Our study suggests that chitin-mediated immunity plays a role in fruit,providing a possible way to reduce fungal infection-related fruit losses by enhancing the chitin-induced immune responses.

Polyphenolic Compounds and Antioxidant Activity of Sea Buckthorn(Hippophae rhamnoides L.)

The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valorization.The aim of the study was to estimate(by HPLC-MS/MS)the qualitative and quantitative content of polyphenolic compounds in different parts of H.rhamnoides(HR),and to determine the level of antioxidant activity of leaves and fruits(by DPPH,ABTS methods and ferrozine test).Up to 19 compounds were identified in different parts of HR.The fruits are rich in flavonoids,including various glycosides of flavonols isorhamnetin,quercetin,and kaempferol.Two isorhamnetin glycosides were not identified in the leaves,while isorhamnetin-3-rhamnosylglactosides and the ellagitannins hippophaenin B,stachyurin and casuarinin were present only in the leaves of the plant.The bark and roots contained considerably more catechins,but minimal flavonols than the fruits and leaves of HR.The total phenolics and flavonols were most abundant in water infusions from leaves of HR(especially quercetin-3-O-glucoside-7-O-rhamnoside),compared to methanolic extracts.No significant differences in the quantitative and qualitative content of the fresh and dried leaves were detected.The highest antioxidant activity by all three methods was detected in the leaves of HR.In addition to the fruits,the leaves may have a perspective as a source of biologically active substances of HR.

Spatiotemporal miRNA and transcriptomic network dynamically regulate the developmental and senescence processes of poplar leaves

Poplar is an important afforestation and urban greening species.Poplar leaf development occurs in stages,from young to mature and then from mature to senescent;these are accompanied by various phenotypic and physiological changes.However,the associated transcriptional regulatory network is relatively unexplored.We first used principal component analysis to classify poplar leaves at different leaf positions into two stages:developmental maturity(the stage of maximum photosynthetic capacity);and the stage when photosynthetic capacity started to decline and gradually changed to senescence.The two stages were then further subdivided into five intervals by gene expression clustering analysis:young leaves,the period of cell genesis and functional differentiation(L1);young leaves,the period of development and initial formation of photosynthetic capacity(L3-L7);the period of maximum photosynthetic capacity of functional leaves(L9-L13);the period of decreasing photosynthetic capacity of functional leaves(L15-L27);and the period of senescent leaves(L29).Using a weighted co-expression gene network analysis of regulatory genes,high-resolution spatiotemporal transcriptional regulatory networks were constructed to reveal the core regulators that regulate leaf development.Spatiotemporal transcriptome data of poplar leaves revealed dynamic changes in genes and miRNAs during leaf development and identified several core regulators of leaf development,such as GRF5 and MYB5.This in-depth analysis of transcriptional regulation during leaf development provides a theoretical basis for exploring the biological basis of the transcriptional regulation of leaf development and the molecular design of breeding for delaying leaf senescence.