Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures;crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transe...Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures;crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transects were located at random in woody vegetation using quadrats 20 m × 20 m which were located every 100 m along 1 km long transects. For every host tree substrate sampled, tree species was identified and bark texture was determined. Presence and location of epiphytes were determined through direct observation. Epiphytes were collected, dried and weighed, so as to apportion biomass between rough and smooth bole textures, crown and trunk as well as stem inclination. Rough bole textured stems had more epiphytes of 1967 kg (89%) than smooth bole substrates of 313.48 kg (11%) and also inclined stems had higher biomass of 85% than vertical stems of 14.64% (χ2 = P < 0.005). Trunk had less biomass of 32% and crown had higher biomass of 68% (Mann Whitney U test 0.002 < P < 0.05). It was concluded that epiphytes were more abundant on rough bole textured substrates and in crown than stem. It would appear that rough bole textured substrates provided better physical anchorage and stability against dislodging forces of wind and rain water, hence being suitable for epiphyte establishment and survival. Inclined substrates on the other hand provided a suitable habitat for accumulation of debris and moisture retention, seed settling, germination, and maximum exposure to sunlight all of which support germination and growth of epiphytes. Further research is required to determine successional colonization, incidences of host species specificity, rain water interception and retention and impact of fire on epiphyte biomass as these are important water catchment attributes.展开更多
Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a com...Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.展开更多
Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes.Little is known about the processes and rates of their death and decomposition when ...Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes.Little is known about the processes and rates of their death and decomposition when they fall from the canopy,which limits our understanding of their role in forest carbon sequestration and nutri-ent cycling.In the temperate rainforest of the Quinault River Valley,Washington State,our aim was to test hypotheses regarding four elements of disturbance that might contribute to their decline.Methods We established set of experiments in which we placed samples of canopy epiphytes and their branch segments:(i)in the canopy versus forest floor microenvironment(stratum);(ii)attached to live versus dead branch substrates;(iii)subjected to physical disruption and‘jarring’;and(iv)in direct versus indirect con-tact with the forest floor.Over the 2-year study,we assigned a non-destructive‘vitality index’(based on color and appar-ent mortality and dryness)to each sample every 2-3 months to compare effects of the experimental treatments and analyzed with a statistical model and post hoc pairwise comparisons of treatments.Important Findings The canopy versus ground stratum and live/dead branch status sig-nificantly affected epiphyte vitality.Effects of physical disruption and ground contact were not significant.There were seasonal effects(low vitality during the sampling times in the summer,revitalization upon sampling times in the winter)for all treatments except samples in contact with the ground.One implication of these results relates to effects of climate change,which is predicted to shift to hotter,drier summers and wetter winters.Climate change may affect forest dynamics and nutrient cycling in unpredictable ways.Results also point to future experiments to understand biotic and abiotic effects on epiphyte disturbance and dynamics.展开更多
Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canop...Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.展开更多
Denitrifying bacteria in epiphytic biofilms play a crucial role in nitrogen cycle in aquatic habitats.However,little is known about the connection between algae and denitrifying bacteria and their assembly processes i...Denitrifying bacteria in epiphytic biofilms play a crucial role in nitrogen cycle in aquatic habitats.However,little is known about the connection between algae and denitrifying bacteria and their assembly processes in epiphytic biofilms.Epiphytic biofilms were collected from submerged macrophytes(Patamogeton lucens and Najas marina L.)in the Caohai Lake,Guizhou,SW China,from July to November 2020 to:(1)investigate the impact of abiotic and biotic variables on denitrifying bacterial communities;(2)investigate the temporal variation of the algae-denitrifying bacteria co-occurrence networks;and(3)determine the contribution of deterministic and stochastic processes to the formation of denitrifying bacterial communities.Abiotic and biotic factors influenced the variation in the denitrifying bacterial community,as shown in the Mantel test.The co-occurrence network analysis unveiled intricate interactions among algae to denitrifying bacteria.Denitrifying bacterial community co-occurrence network complexity(larger average degrees representing stronger network complexity)increased continuously from July to September and decreased in October before increasing in November.The co-occurrence network complexity of the algae and nirS-encoding denitrifying bacteria tended to increase from July to November.The co-occurrence network complexity of the algal and denitrifying bacterial communities was modified by ammonia nitrogen(NH_(4)^(+)-N)and total phosphorus(TP),pH,and water temperature(WT),according to the ordinary least-squares(OLS)model.The modified stochasticity ratio(MST)results reveal that deterministic selection dominated the assembly of denitrifying bacterial communities.The influence of environmental variables to denitrifying bacterial communities,as well as characteristics of algal-bacterial co-occurrence networks and the assembly process of denitrifying bacterial communities,were discovered in epiphytic biofilms in this study.The findings could aid in the appropriate understanding and use of epiphytic biofilms denitrification function,as well as the enhancement of water quality.展开更多
The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyro...The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyropia katadae,two nori species of Neopyropia living at the same tidal level but with distinct physiological states and living habits,were investigated to understand the differences between them and the effects of epiphytic bacteria on their differential characteristics.Analysis of 16S rRNA gene sequences and real-time quantitative PCR(qPCR)of thalli and seawater samples(n=24)revealed notable differences in microbial diversity and community structure between the two species.Bacteroidetes dominated the bacterial communities in association with N.yezoensis,whereas Proteobacteria were predominant in N.katadae.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt2)analysis revealed enriched genes that related to the ABC transport system,iron complex outer membrane receptor proteins,and proliferation in N.yezoensis,whereas N.katadae exhibited enrichment of genes that related to energy supply as well as cell wall and cell membrane production.The results of qPCR indicate a higher abundance of epiphytic bacteria on surface of N.yezoensis than those on surface of N.katadae.The findings indicate that differences in the living environments of N.yezoensis and N.katadae may result in distinct structural composition and abundance of epiphytic bacteria on their surfaces,thereby conferring specific biological functionalities to each microbial community,and the epiphytic bacteria may shape the living habits of hosts to some extents.This study provided a basis for understanding the close association between surface microorganisms and algal bodies,and the physiological and ecological characteristics of nori species.展开更多
In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC)...In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.展开更多
A study on the spatial and seasonal variations of the associate macroalgae and epiphytes of Thalassia testudinum was carried out in Bahía de Nuevitas. Sixty-two species were identified: 3 Cyanophyta, 25 Chlorophy...A study on the spatial and seasonal variations of the associate macroalgae and epiphytes of Thalassia testudinum was carried out in Bahía de Nuevitas. Sixty-two species were identified: 3 Cyanophyta, 25 Chlorophyta, 8 Phaeophyceae, 23 Rhodophyta and 3 Magnoliophyta, with two new records for Cuba and 43 for the area. The differences in the specific composition of the macroalgae communities are determined by a space component related to the type of affectation in each area. The morpho-functional groups of macroalgae in the station with more nutrient influence were mainly foliaceous and filamentous. In the stations far from the city, the predominant morpho-types were the leathery and articulate calcareous indicators of lower nitrification levels. The abundance and diversity of macroalgae in the site affected by fisheries were lower due to the damage by bottom trawls. Seasonal variations were found in the relative abundance of the species, not in the diversity, which makes evident seasonal changes in the structure of the seaweeds, where some species replace others in the community.展开更多
Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is c...Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is consistently threatened by illegal trade and habitat transformation.Here,we identified areas critical for orchid conservation in the biogeographic province of Megamexico.For this purpose,we evaluated orchid endemism,phylogenetic diversity,and phylogenetic endemism within Megamexico and characterized orchid life forms.Our results indicate that the majority of the regions with the highest estimates of endemism and phylogenetic endemism are in southern Mexico and northern Central America,mostly located on the Pacific side of Megamexico.Among the most important orchid lineages,several belong to epiphytic lineages such as Pleurothallidinae,Laeliinae and Oncidiinae.We also found that species from diverse and distantly related lineages converge in montane forests where suitable substrates for epiphytes abound.Furthermore,the southernmost areas of phylogenetic diversity and endemism of Megamexico are in unprotected areas.Thus,we conclude that the most critical areas for orchid conservation in Megamexico are located in southern Mexico and northern Central America.We recommend that these areas should be given priority by the Mexican system of natural protected areas as complementary conservation areas.展开更多
The article presents information about the taxonomy and ecology of lichens in the Ohaliksai River basin. According to the conducted studies, 11 families <span>of the Lecanoromycetes class (Parmeliaceae, </spa...The article presents information about the taxonomy and ecology of lichens in the Ohaliksai River basin. According to the conducted studies, 11 families <span>of the Lecanoromycetes class (Parmeliaceae, </span></span><span style="font-size:10.0pt;font-family:"">Lecanoraceae</span><span style="font-size:10.0pt;font-family:"">, Ramalinaceae, M</span><span style="font-size:10.0pt;font-family:"">e<span>gasporaceae, Physciaceae, Teloschistaceae, Peltigeraceae, Collemataceae, Ca</span>n<span>delariaceae, Umbilicariaceae, Physciaceae), 1 family of the Eurotiomycetes cla</span>ss (Verrucariaceae) and 1 family Lichinaceae of the class Lichinomycetes were identified, 18 groups and 23 species were noted as widespread. The taxonomic<span> analysis and ecological characteristics of the identified specie</span>s are presented.展开更多
Vascular epiphytes are one of the most important forest components,contributing to microclimatic maintenance.These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high t...Vascular epiphytes are one of the most important forest components,contributing to microclimatic maintenance.These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high temperature and humidity typical of this biome.In recent years,the Brazilian Amazon has undergone dramatic changes in its landscape,mainly due to the increase in deforestation and fire rates.We present here the floristic composition and analyze the community structure of epiphytic angiosperms of an urban forest fragment in Eastern Amazon.A total of 71 epiphytic individuals were recorded belonging to eight species and four families.Orchidaceae was the most representative family,corroborating the pattern for surveys of epiphytic diversity in the Neotropical region.Epiphytic species were found on 24 individuals of 10 tree species.The epiphytic importance value(IVe)was low for all species,except for Aechmea tocantina and Rhipsalis baccifera.Cactaceae was the family with the highest IVe.Most epiphytes were found in the crown of trees(83.1%).The diversity index of the fragment was H’=1.80 and the equity index was J=0.87,reflecting the absence of highly dominant species.Conservation of urban forest fragments is necessary for the maintenance of epiphytic flora and ecosystem services.展开更多
Various species of mangrove trees thrive in the mangrove forests of Calabarzon,Philippines including species of Avicennia marina,Rhizophora mucronata,and Rhizophora apiculata,which house various lichen species but ver...Various species of mangrove trees thrive in the mangrove forests of Calabarzon,Philippines including species of Avicennia marina,Rhizophora mucronata,and Rhizophora apiculata,which house various lichen species but very little available information on the diversity of these epiphytes is known.A survey of 90 decaying mangrove woods from 3 mangrove sites in Calabarzon including Laiya Batangas,Tanza Cavite and Pagbilao Quezon recorded a total of 40 lichen species classified under 25 genera and 14 families.Rhizophora apiculata(bakawang lalaki)was found the most preferred lichen establishment host as it housed 23 lichen species followed by Rhizophora mucronata(bakawang babae)with 17 lichen species and Avicenia marina with 7 lichen species.Lichens that belong to family Arthoniaceae,Caliciaceae,Parmeliaceae,Collemataceae,and Graphidaceae were the highest recorded.Most of these manglicolous lichens were classified as crustose(60%)and foliose(40%)lichens.Out of these manglicolous lichens identified,29 species were found to be new records of lichens in the Philippines.展开更多
This study describes the anatomy of sterile leaves of Elaphoglossum discolor (Kuhn) C. Chr., E. flaccidum (Fée) T. Moore and E. laminarioides (Bory ex Fée) T. Moore, the most representative species of the ge...This study describes the anatomy of sterile leaves of Elaphoglossum discolor (Kuhn) C. Chr., E. flaccidum (Fée) T. Moore and E. laminarioides (Bory ex Fée) T. Moore, the most representative species of the genus in the Ecological Park of Gunma in Pará State. It reports the main diagnostic characters and provides new systematic data for the group. In addition, it locates the production and accumulation sites of bioactive compounds to determine possible adaptive strategies of these species in the Amazon rainforest environment. Diagnostic structural features include stoma typology, central veins and margin forms, type of mesophyll, and the presence of schlerenchymatous sheaths in the cortex, among others. Among the bioactive compounds related to defense adaptation are phenolic compounds, which occur in all three species, and alkaloids and mucilage, which are exclusive to E. laminarioides. Of the three species studied, E. laminarioides has features that make it the best suited to the rainforest environment.展开更多
To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microc...To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microcystis strains in a laboratory experiment.Results showed that both Mcracystis cell extracts exerted obvious damages to plant biomass,photosynthesis,primary and secondary metabolism measures,and resistance of plant antioxidant systems,with MC-producing Microcystis having stronger effects due to the presence of MCs.Cyanotoxins other than MCs responsible for the negative effects from both strains needs further identification.The Shannon diversity and Chao1 indices of epiphytic and planktonic bacteria were decreased by the cell extracts from both Microcystis strains.However,epiphytic and planktonic bacterial communities responded differently to cell extracts at the genus level.The dominant genera of planktonic bacteria including Enterobacter,Pseudomonas,and Novosphingobium from phylum Proteobacteria,Chryseobacterium from phylum Bacteroidetes,and Microbacterium from Actinobacteriota in the treatments with cell extracts were previously reported to have strains with algicidal and MC-degrading capabilities.B acterial genes associated with energy production and conversion,amino acid transport and metabolism,and inorganic ion transport and metabolism,were more abundant in both treatments than the control for planktonic bacteria,but less abundant for epiphytic bacteria.We speculate that planktonic bacterial communities have the potential to use and degrade substances derived from Microcystis cell extracts,which may be beneficial for M.spicatum to alleviate damages from Microcystis.Further research is needed to verify the structure and function dynamics of epiphytic and planktonic bacteria in the interaction between cyanobacteria and submerged macrophytes.展开更多
Mycorrhizal fungi are essential for the growth and development of both epiphytic(growing on trees)and lithophytic(growing on rocks)orchids.Previous studies indicate that in lowland tropical areas,orchid mycorrhizal fu...Mycorrhizal fungi are essential for the growth and development of both epiphytic(growing on trees)and lithophytic(growing on rocks)orchids.Previous studies indicate that in lowland tropical areas,orchid mycorrhizal fungal compositions are correlated with the life form(i.e.,epiphytic,lithophytic,or terrestrial)of their host plants.We therefore tested if a similar correlation exists in an orchid distributed at higher elevations.Coelogyne corymbosa is an endangered ornamental orchid species that can be found as a lithophyte and epiphyte in subtropical to subalpine areas.Based on high-throughput sequencing of the fungal internal transcribed spacer 2(ITS2)-rDNA region of mycorrhizae of C.corymbosa,we detected 73 putative mycorrhizal fungal Operational Taxonomic Units(OTUs).The OTUs of two dominant lineages(Cantharellales and Sebacinales)detected from C.corymbosa are phylogenetically different from those of other species within the genus Coelogyne,indicating that different orchid species prefer specific mycorrhizal fungi.We also found that the Non-metric multidimensional scaling(NMDS)plots of orchid mycorrhizal fungi were not clustered with life form,the variations among orchid mycorrhizal fungal communities of different life forms were not significant,and most of the OTUs detected from epiphytic individuals were shared by the lithophytic plants,suggesting that orchid mycorrhizal associations of C.corymbosa were not affected by life form.These findings provide novel insights into mycorrhizal associations with endangered ornamental orchids.展开更多
Denitrifying bacteria are a crucial component of aquatic ecosystem in nitrogen cycle.However,the denitrifying bacterial community dynamics and structure in epiphytic biofilms remain unexplored.The abundance of denitri...Denitrifying bacteria are a crucial component of aquatic ecosystem in nitrogen cycle.However,the denitrifying bacterial community dynamics and structure in epiphytic biofilms remain unexplored.The abundance of denitrification gene(nir)and structure of nirS-denitrifying bacterial community in the epiphytic biofilms collected in July and November of 2018 from a typical plateau lake(Caohai Wetland,Guizhou,China)were studied by Real-time Quantitative Polymerase Chain Reaction(qPCR)and highthroughput sequencing.Results show that the gene abundance of nirK was higher than that of nirS(P<0.05),and it was significantly different during the growth period(July)than the decline period(November).The denitrifying bacterial species was similar in the two months and shared 76.18%of OTUs.Proteobacteria(56.55%±22.15%)was the dominant phylum in all the samples.Epiphytic biofilms between growth period and decline period displayed significantly different microbial community structures due to differences in species abundance.Water temperature was the crucial factor that affected the denitrifying microbial community structure in our study.Environmental factors explain only partially the dynamic characteristics of denitrifying microbial communities,implying that the stochastic processes affected the construction of denitrifying microbial communities.As the null model analysis results show,dispersal limitation(stochastic)and undominated processes significantly influenced the assembly of denitrifying microbial communities.This study broadened our understanding of the denitrifying bacterial community structure and its function on epiphytic biofilms in freshwater ecosystems with new information provided.展开更多
Plants harbor diverse fungal communities both on their surfaces(epiphytic)and inside of plant tissues(endophytic),and these fungi play important roles in plant health and vigor.However,comparisons of epiphytes and end...Plants harbor diverse fungal communities both on their surfaces(epiphytic)and inside of plant tissues(endophytic),and these fungi play important roles in plant health and vigor.However,comparisons of epiphytes and endophytes have rarely been performed.In this study,the soil,epiphytic and endophytic fungal assemblages of greenhouse-grown tomato plants were extensively examined and compared by Illumina sequencing of 18S rRNA amplicons.The fungal communities differed in both size and composition.The soil communities were the richest and most abundant,while the endophytes showed the lowest richness and diversity.The diversity of endophytes also differed in different tissues,with the highest diversity occurring in the roots.In both the epiphytic and endophytic samples,the majority of fungi corresponded to ascomycetes,amongwhich Sordariomycetes,Dothideomycetes and Eurotiomyceteswere the most frequent classes.Themajor non-ascomycete fungi were associated only with the class Exobasidiomycetes(Basidiomycota).At the order level,the epiphytes showed similar distribution patterns in the stems and leaves,but among the endophytes,distinct fungal orders were enriched in different tissues.Capnodialeswas recorded as amajor fungal group in the stems,leaves and seeds,and Saccharomycetales was specifically enriched in the pericarp and jelly around seeds.The present data suggested that different drivers shaped epiphytic and endophytic fungi communities and deepened our knowledge of the complex plant-fungus interaction in tomato.展开更多
The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history ...The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history of the marine biodiversity. In fact, the digs expose fossil leaf of Posidonia oceanica with epiphytic communities of microorganisms. Posidonia oceanica is a seagrass endemic to theMediterraneanthat forms large meadows whose remains can persist in the sediment for thousands of years. In this communication, we report results of analyses carried out using both molecular and morphological techniques on sub-fossil leaves of P. oceanica and their associated epiphytic communities.展开更多
Tara (Caesalpinia spinose Molina Kuntz) is a native plant of the Bolivian Andes. A number of projects have promoted the cultivation of this species over the last 20 years, in efforts to make use of its medicinal, food...Tara (Caesalpinia spinose Molina Kuntz) is a native plant of the Bolivian Andes. A number of projects have promoted the cultivation of this species over the last 20 years, in efforts to make use of its medicinal, food and industrial properties. However, as tara plantations have grown, so too has the incidence of disease affecting the species, leading to economic losses. The aim of the present work was to identify the causal agent of wilting in tara, and to determine the incidence of the disease in nursery-grown plants. Three experimental plots (R1-R3) were established in plantlet production bedsat the ESFOR nursery in order to assess the incidence of wilting. Plant spacing was 1 × 1 m. At the two leaf stage, samples of diseased and apparently healthy plants were taken to the laboratory for the isolation of pathogens. Both the apparently healthy and diseased plants gave rise to the same kinds of fungal colony on PDA. Microscopic examination revealed microconidia, macroconidia, phialides and chlamydospores suggesting the causal agent to be Fusarium oxysporum. Over the (up to) 84-day period following thinning, the incidence of wilting for 2010 was R1 = 2.56%, R2 = 3.15% and R3 = 2.22% per 14 days, and for 2013 it was R1 = 1.24%, R2 = 2.45% and R3 = 2.13% per 14 days;the apparent infection rates for 2010 were rR1 = 0.0003/day, rR2 = 0.0003/day and rR3 = 0.0003/day, and for 2013 they were rR1 = 0.0003/day, rR2 = 0.0004/day and rR3 = 0.0003/day. These values are characteristic of monocyclic epiphytic fungi such as F. oxysporum.展开更多
The established culture of gametophytes of the red alga Pyropia yezoensis (TU-1) is superficially colonized by epiphytic bacteria. By 16S rRNA sequencing, 6 bacterial species were identified, and a culturable bacteriu...The established culture of gametophytes of the red alga Pyropia yezoensis (TU-1) is superficially colonized by epiphytic bacteria. By 16S rRNA sequencing, 6 bacterial species were identified, and a culturable bacterium, Neptunomonas sp. BPy-1, was isolated. The 16S rRNA sequences of BPy-1 showed 100% identity with that of Neptunomonas sp. 0536, a probiotic bacterium found in greenshell mussels in New Zealand. Physiological tests revealed that 22 characters were identical between BPy-1 and 0536, but that 4 characters differed. BPy-1 cannot grow in the artificial seawater used for the culture of gametophytes. BPy-1 can grow in the artificial seawater with ethanol or butanol but not in methanol or propanol. To determine the effect of BPy-1 on gametophyte growth, BPy-1 colonization was reduced by 80% using a multi-enzyme cleaner. Changing the cleaner concentration yielded two types of gametophytes, a compressed or callus-like form and a nearly normal form. BPy-1 promoted the growth of the treated gametophytes with relatively normal form, while it showed less effect on compressed gametophytes. These findings suggested that BPy-1 promotes the growth of damaged gametophytes but does not affect the development of normal gametophytes.展开更多
文摘Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures;crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transects were located at random in woody vegetation using quadrats 20 m × 20 m which were located every 100 m along 1 km long transects. For every host tree substrate sampled, tree species was identified and bark texture was determined. Presence and location of epiphytes were determined through direct observation. Epiphytes were collected, dried and weighed, so as to apportion biomass between rough and smooth bole textures, crown and trunk as well as stem inclination. Rough bole textured stems had more epiphytes of 1967 kg (89%) than smooth bole substrates of 313.48 kg (11%) and also inclined stems had higher biomass of 85% than vertical stems of 14.64% (χ2 = P < 0.005). Trunk had less biomass of 32% and crown had higher biomass of 68% (Mann Whitney U test 0.002 < P < 0.05). It was concluded that epiphytes were more abundant on rough bole textured substrates and in crown than stem. It would appear that rough bole textured substrates provided better physical anchorage and stability against dislodging forces of wind and rain water, hence being suitable for epiphyte establishment and survival. Inclined substrates on the other hand provided a suitable habitat for accumulation of debris and moisture retention, seed settling, germination, and maximum exposure to sunlight all of which support germination and growth of epiphytes. Further research is required to determine successional colonization, incidences of host species specificity, rain water interception and retention and impact of fire on epiphyte biomass as these are important water catchment attributes.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB31000000)to D.-Z.L.and J.-B.Y.CAS Pioneer Hundred Talents Program to A.Z.+1 种基金the Project for Innovation Team of Yunnan Province(grant no.202105AE160012)to S.-B.Z.the Science and Technology Basic Resources Investigation Program of China(grant no.2021FY100200)to J.-B.Y.
文摘Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.
基金National Science Foundation(EHR 15-14494 and DEB 11-41833 to N.M.N.and DBI 1400456 to K.D.K.).
文摘Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes.Little is known about the processes and rates of their death and decomposition when they fall from the canopy,which limits our understanding of their role in forest carbon sequestration and nutri-ent cycling.In the temperate rainforest of the Quinault River Valley,Washington State,our aim was to test hypotheses regarding four elements of disturbance that might contribute to their decline.Methods We established set of experiments in which we placed samples of canopy epiphytes and their branch segments:(i)in the canopy versus forest floor microenvironment(stratum);(ii)attached to live versus dead branch substrates;(iii)subjected to physical disruption and‘jarring’;and(iv)in direct versus indirect con-tact with the forest floor.Over the 2-year study,we assigned a non-destructive‘vitality index’(based on color and appar-ent mortality and dryness)to each sample every 2-3 months to compare effects of the experimental treatments and analyzed with a statistical model and post hoc pairwise comparisons of treatments.Important Findings The canopy versus ground stratum and live/dead branch status sig-nificantly affected epiphyte vitality.Effects of physical disruption and ground contact were not significant.There were seasonal effects(low vitality during the sampling times in the summer,revitalization upon sampling times in the winter)for all treatments except samples in contact with the ground.One implication of these results relates to effects of climate change,which is predicted to shift to hotter,drier summers and wetter winters.Climate change may affect forest dynamics and nutrient cycling in unpredictable ways.Results also point to future experiments to understand biotic and abiotic effects on epiphyte disturbance and dynamics.
基金The National Natural Science Foundation of China under contract Nos 32170127 and 42176156the Fundamental Research Funds for the Central Universities under contract No.202141006。
文摘Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.
基金Supported by the National Natural Science Foundation of China(No.41867056)the Guizhou Provincial Key Technology R&D Program(Nos.2021470,2023216)。
文摘Denitrifying bacteria in epiphytic biofilms play a crucial role in nitrogen cycle in aquatic habitats.However,little is known about the connection between algae and denitrifying bacteria and their assembly processes in epiphytic biofilms.Epiphytic biofilms were collected from submerged macrophytes(Patamogeton lucens and Najas marina L.)in the Caohai Lake,Guizhou,SW China,from July to November 2020 to:(1)investigate the impact of abiotic and biotic variables on denitrifying bacterial communities;(2)investigate the temporal variation of the algae-denitrifying bacteria co-occurrence networks;and(3)determine the contribution of deterministic and stochastic processes to the formation of denitrifying bacterial communities.Abiotic and biotic factors influenced the variation in the denitrifying bacterial community,as shown in the Mantel test.The co-occurrence network analysis unveiled intricate interactions among algae to denitrifying bacteria.Denitrifying bacterial community co-occurrence network complexity(larger average degrees representing stronger network complexity)increased continuously from July to September and decreased in October before increasing in November.The co-occurrence network complexity of the algae and nirS-encoding denitrifying bacteria tended to increase from July to November.The co-occurrence network complexity of the algal and denitrifying bacterial communities was modified by ammonia nitrogen(NH_(4)^(+)-N)and total phosphorus(TP),pH,and water temperature(WT),according to the ordinary least-squares(OLS)model.The modified stochasticity ratio(MST)results reveal that deterministic selection dominated the assembly of denitrifying bacterial communities.The influence of environmental variables to denitrifying bacterial communities,as well as characteristics of algal-bacterial co-occurrence networks and the assembly process of denitrifying bacterial communities,were discovered in epiphytic biofilms in this study.The findings could aid in the appropriate understanding and use of epiphytic biofilms denitrification function,as well as the enhancement of water quality.
基金Supported by the National Natural Science Foundation of China(Nos.42276148,41976133)。
文摘The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyropia katadae,two nori species of Neopyropia living at the same tidal level but with distinct physiological states and living habits,were investigated to understand the differences between them and the effects of epiphytic bacteria on their differential characteristics.Analysis of 16S rRNA gene sequences and real-time quantitative PCR(qPCR)of thalli and seawater samples(n=24)revealed notable differences in microbial diversity and community structure between the two species.Bacteroidetes dominated the bacterial communities in association with N.yezoensis,whereas Proteobacteria were predominant in N.katadae.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt2)analysis revealed enriched genes that related to the ABC transport system,iron complex outer membrane receptor proteins,and proliferation in N.yezoensis,whereas N.katadae exhibited enrichment of genes that related to energy supply as well as cell wall and cell membrane production.The results of qPCR indicate a higher abundance of epiphytic bacteria on surface of N.yezoensis than those on surface of N.katadae.The findings indicate that differences in the living environments of N.yezoensis and N.katadae may result in distinct structural composition and abundance of epiphytic bacteria on their surfaces,thereby conferring specific biological functionalities to each microbial community,and the epiphytic bacteria may shape the living habits of hosts to some extents.This study provided a basis for understanding the close association between surface microorganisms and algal bodies,and the physiological and ecological characteristics of nori species.
文摘In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.
文摘A study on the spatial and seasonal variations of the associate macroalgae and epiphytes of Thalassia testudinum was carried out in Bahía de Nuevitas. Sixty-two species were identified: 3 Cyanophyta, 25 Chlorophyta, 8 Phaeophyceae, 23 Rhodophyta and 3 Magnoliophyta, with two new records for Cuba and 43 for the area. The differences in the specific composition of the macroalgae communities are determined by a space component related to the type of affectation in each area. The morpho-functional groups of macroalgae in the station with more nutrient influence were mainly foliaceous and filamentous. In the stations far from the city, the predominant morpho-types were the leathery and articulate calcareous indicators of lower nitrification levels. The abundance and diversity of macroalgae in the site affected by fisheries were lower due to the damage by bottom trawls. Seasonal variations were found in the relative abundance of the species, not in the diversity, which makes evident seasonal changes in the structure of the seaweeds, where some species replace others in the community.
基金The study was carried out with the support of CONACyT,which awarded an M.Sc.scholarship to BEGR(CVU935962)through the Instituto de Ecología,A.C.
文摘Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is consistently threatened by illegal trade and habitat transformation.Here,we identified areas critical for orchid conservation in the biogeographic province of Megamexico.For this purpose,we evaluated orchid endemism,phylogenetic diversity,and phylogenetic endemism within Megamexico and characterized orchid life forms.Our results indicate that the majority of the regions with the highest estimates of endemism and phylogenetic endemism are in southern Mexico and northern Central America,mostly located on the Pacific side of Megamexico.Among the most important orchid lineages,several belong to epiphytic lineages such as Pleurothallidinae,Laeliinae and Oncidiinae.We also found that species from diverse and distantly related lineages converge in montane forests where suitable substrates for epiphytes abound.Furthermore,the southernmost areas of phylogenetic diversity and endemism of Megamexico are in unprotected areas.Thus,we conclude that the most critical areas for orchid conservation in Megamexico are located in southern Mexico and northern Central America.We recommend that these areas should be given priority by the Mexican system of natural protected areas as complementary conservation areas.
文摘The article presents information about the taxonomy and ecology of lichens in the Ohaliksai River basin. According to the conducted studies, 11 families <span>of the Lecanoromycetes class (Parmeliaceae, </span></span><span style="font-size:10.0pt;font-family:"">Lecanoraceae</span><span style="font-size:10.0pt;font-family:"">, Ramalinaceae, M</span><span style="font-size:10.0pt;font-family:"">e<span>gasporaceae, Physciaceae, Teloschistaceae, Peltigeraceae, Collemataceae, Ca</span>n<span>delariaceae, Umbilicariaceae, Physciaceae), 1 family of the Eurotiomycetes cla</span>ss (Verrucariaceae) and 1 family Lichinaceae of the class Lichinomycetes were identified, 18 groups and 23 species were noted as widespread. The taxonomic<span> analysis and ecological characteristics of the identified specie</span>s are presented.
文摘Vascular epiphytes are one of the most important forest components,contributing to microclimatic maintenance.These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high temperature and humidity typical of this biome.In recent years,the Brazilian Amazon has undergone dramatic changes in its landscape,mainly due to the increase in deforestation and fire rates.We present here the floristic composition and analyze the community structure of epiphytic angiosperms of an urban forest fragment in Eastern Amazon.A total of 71 epiphytic individuals were recorded belonging to eight species and four families.Orchidaceae was the most representative family,corroborating the pattern for surveys of epiphytic diversity in the Neotropical region.Epiphytic species were found on 24 individuals of 10 tree species.The epiphytic importance value(IVe)was low for all species,except for Aechmea tocantina and Rhipsalis baccifera.Cactaceae was the family with the highest IVe.Most epiphytes were found in the crown of trees(83.1%).The diversity index of the fragment was H’=1.80 and the equity index was J=0.87,reflecting the absence of highly dominant species.Conservation of urban forest fragments is necessary for the maintenance of epiphytic flora and ecosystem services.
基金the College of Science,University of Santo Tomas the Fungal Biodiversity Ecogenomics and Systematics(FBeS)Group for their unwavering support in the performance of this study.
文摘Various species of mangrove trees thrive in the mangrove forests of Calabarzon,Philippines including species of Avicennia marina,Rhizophora mucronata,and Rhizophora apiculata,which house various lichen species but very little available information on the diversity of these epiphytes is known.A survey of 90 decaying mangrove woods from 3 mangrove sites in Calabarzon including Laiya Batangas,Tanza Cavite and Pagbilao Quezon recorded a total of 40 lichen species classified under 25 genera and 14 families.Rhizophora apiculata(bakawang lalaki)was found the most preferred lichen establishment host as it housed 23 lichen species followed by Rhizophora mucronata(bakawang babae)with 17 lichen species and Avicenia marina with 7 lichen species.Lichens that belong to family Arthoniaceae,Caliciaceae,Parmeliaceae,Collemataceae,and Graphidaceae were the highest recorded.Most of these manglicolous lichens were classified as crustose(60%)and foliose(40%)lichens.Out of these manglicolous lichens identified,29 species were found to be new records of lichens in the Philippines.
基金The authors thank Dr.Alejandra Vasco,New York Bo-tanical Garden(NYBG),for information on the systema-tics studies in the groupthe National Council for Sci-entific and Technological Development(CNPq)for the Master scholarship of the first author(CNPq 132809/2009-5).
文摘This study describes the anatomy of sterile leaves of Elaphoglossum discolor (Kuhn) C. Chr., E. flaccidum (Fée) T. Moore and E. laminarioides (Bory ex Fée) T. Moore, the most representative species of the genus in the Ecological Park of Gunma in Pará State. It reports the main diagnostic characters and provides new systematic data for the group. In addition, it locates the production and accumulation sites of bioactive compounds to determine possible adaptive strategies of these species in the Amazon rainforest environment. Diagnostic structural features include stoma typology, central veins and margin forms, type of mesophyll, and the presence of schlerenchymatous sheaths in the cortex, among others. Among the bioactive compounds related to defense adaptation are phenolic compounds, which occur in all three species, and alkaloids and mucilage, which are exclusive to E. laminarioides. Of the three species studied, E. laminarioides has features that make it the best suited to the rainforest environment.
基金Supported by the National Program for the Introduction of High-end Foreign Experts(No.G2021026024L)the National Natural Science Foundation of China(Nos.31700405,U1904124)+1 种基金the Major Public Welfare Projects in Henan Province(No.201300311300)the Breeding Project of Henan Normal University(No.HNU2021PL05)。
文摘To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microcystis strains in a laboratory experiment.Results showed that both Mcracystis cell extracts exerted obvious damages to plant biomass,photosynthesis,primary and secondary metabolism measures,and resistance of plant antioxidant systems,with MC-producing Microcystis having stronger effects due to the presence of MCs.Cyanotoxins other than MCs responsible for the negative effects from both strains needs further identification.The Shannon diversity and Chao1 indices of epiphytic and planktonic bacteria were decreased by the cell extracts from both Microcystis strains.However,epiphytic and planktonic bacterial communities responded differently to cell extracts at the genus level.The dominant genera of planktonic bacteria including Enterobacter,Pseudomonas,and Novosphingobium from phylum Proteobacteria,Chryseobacterium from phylum Bacteroidetes,and Microbacterium from Actinobacteriota in the treatments with cell extracts were previously reported to have strains with algicidal and MC-degrading capabilities.B acterial genes associated with energy production and conversion,amino acid transport and metabolism,and inorganic ion transport and metabolism,were more abundant in both treatments than the control for planktonic bacteria,but less abundant for epiphytic bacteria.We speculate that planktonic bacterial communities have the potential to use and degrade substances derived from Microcystis cell extracts,which may be beneficial for M.spicatum to alleviate damages from Microcystis.Further research is needed to verify the structure and function dynamics of epiphytic and planktonic bacteria in the interaction between cyanobacteria and submerged macrophytes.
基金We thank Jia-Lin Huang and Jia-Wei Li for their kind help with field work.John Meadows and Raymond Porter are acknowledged for improvements of the manuscript.This study was supported by the National Natural Science Foundation of China(Nos.31670342 and 31700026)Yunnan Applied Basic Research Project(2019FB019)+1 种基金the Science and Technology Plan of Yunnan(2018BB010)the Scientific and Technological Leading Talent Project of Yunnan Province(2016HA005).
文摘Mycorrhizal fungi are essential for the growth and development of both epiphytic(growing on trees)and lithophytic(growing on rocks)orchids.Previous studies indicate that in lowland tropical areas,orchid mycorrhizal fungal compositions are correlated with the life form(i.e.,epiphytic,lithophytic,or terrestrial)of their host plants.We therefore tested if a similar correlation exists in an orchid distributed at higher elevations.Coelogyne corymbosa is an endangered ornamental orchid species that can be found as a lithophyte and epiphyte in subtropical to subalpine areas.Based on high-throughput sequencing of the fungal internal transcribed spacer 2(ITS2)-rDNA region of mycorrhizae of C.corymbosa,we detected 73 putative mycorrhizal fungal Operational Taxonomic Units(OTUs).The OTUs of two dominant lineages(Cantharellales and Sebacinales)detected from C.corymbosa are phylogenetically different from those of other species within the genus Coelogyne,indicating that different orchid species prefer specific mycorrhizal fungi.We also found that the Non-metric multidimensional scaling(NMDS)plots of orchid mycorrhizal fungi were not clustered with life form,the variations among orchid mycorrhizal fungal communities of different life forms were not significant,and most of the OTUs detected from epiphytic individuals were shared by the lithophytic plants,suggesting that orchid mycorrhizal associations of C.corymbosa were not affected by life form.These findings provide novel insights into mycorrhizal associations with endangered ornamental orchids.
基金*Supported by the National Natural Science Foundation of China(No.41867056)the Joint Fund of the National Natural Science Foundation of China and the Karst Science Research Center of Guizhou Province(No.U1812401)+1 种基金the Guizhou Province Graduate Education Innovation Project(No.YJSCXJH(2019)048)the Science and Technology Support Project of Guizhou Province(No.2021470)。
文摘Denitrifying bacteria are a crucial component of aquatic ecosystem in nitrogen cycle.However,the denitrifying bacterial community dynamics and structure in epiphytic biofilms remain unexplored.The abundance of denitrification gene(nir)and structure of nirS-denitrifying bacterial community in the epiphytic biofilms collected in July and November of 2018 from a typical plateau lake(Caohai Wetland,Guizhou,China)were studied by Real-time Quantitative Polymerase Chain Reaction(qPCR)and highthroughput sequencing.Results show that the gene abundance of nirK was higher than that of nirS(P<0.05),and it was significantly different during the growth period(July)than the decline period(November).The denitrifying bacterial species was similar in the two months and shared 76.18%of OTUs.Proteobacteria(56.55%±22.15%)was the dominant phylum in all the samples.Epiphytic biofilms between growth period and decline period displayed significantly different microbial community structures due to differences in species abundance.Water temperature was the crucial factor that affected the denitrifying microbial community structure in our study.Environmental factors explain only partially the dynamic characteristics of denitrifying microbial communities,implying that the stochastic processes affected the construction of denitrifying microbial communities.As the null model analysis results show,dispersal limitation(stochastic)and undominated processes significantly influenced the assembly of denitrifying microbial communities.This study broadened our understanding of the denitrifying bacterial community structure and its function on epiphytic biofilms in freshwater ecosystems with new information provided.
基金This work was supported by grants from the National Key Research and Development Program of China(Grant No.2016YED0201003)the China Agriculture Research System(Grant No.CARS-25)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAASASTIP-IVFCAAS).
文摘Plants harbor diverse fungal communities both on their surfaces(epiphytic)and inside of plant tissues(endophytic),and these fungi play important roles in plant health and vigor.However,comparisons of epiphytes and endophytes have rarely been performed.In this study,the soil,epiphytic and endophytic fungal assemblages of greenhouse-grown tomato plants were extensively examined and compared by Illumina sequencing of 18S rRNA amplicons.The fungal communities differed in both size and composition.The soil communities were the richest and most abundant,while the endophytes showed the lowest richness and diversity.The diversity of endophytes also differed in different tissues,with the highest diversity occurring in the roots.In both the epiphytic and endophytic samples,the majority of fungi corresponded to ascomycetes,amongwhich Sordariomycetes,Dothideomycetes and Eurotiomyceteswere the most frequent classes.Themajor non-ascomycete fungi were associated only with the class Exobasidiomycetes(Basidiomycota).At the order level,the epiphytes showed similar distribution patterns in the stems and leaves,but among the endophytes,distinct fungal orders were enriched in different tissues.Capnodialeswas recorded as amajor fungal group in the stems,leaves and seeds,and Saccharomycetales was specifically enriched in the pericarp and jelly around seeds.The present data suggested that different drivers shaped epiphytic and endophytic fungi communities and deepened our knowledge of the complex plant-fungus interaction in tomato.
文摘The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history of the marine biodiversity. In fact, the digs expose fossil leaf of Posidonia oceanica with epiphytic communities of microorganisms. Posidonia oceanica is a seagrass endemic to theMediterraneanthat forms large meadows whose remains can persist in the sediment for thousands of years. In this communication, we report results of analyses carried out using both molecular and morphological techniques on sub-fossil leaves of P. oceanica and their associated epiphytic communities.
文摘Tara (Caesalpinia spinose Molina Kuntz) is a native plant of the Bolivian Andes. A number of projects have promoted the cultivation of this species over the last 20 years, in efforts to make use of its medicinal, food and industrial properties. However, as tara plantations have grown, so too has the incidence of disease affecting the species, leading to economic losses. The aim of the present work was to identify the causal agent of wilting in tara, and to determine the incidence of the disease in nursery-grown plants. Three experimental plots (R1-R3) were established in plantlet production bedsat the ESFOR nursery in order to assess the incidence of wilting. Plant spacing was 1 × 1 m. At the two leaf stage, samples of diseased and apparently healthy plants were taken to the laboratory for the isolation of pathogens. Both the apparently healthy and diseased plants gave rise to the same kinds of fungal colony on PDA. Microscopic examination revealed microconidia, macroconidia, phialides and chlamydospores suggesting the causal agent to be Fusarium oxysporum. Over the (up to) 84-day period following thinning, the incidence of wilting for 2010 was R1 = 2.56%, R2 = 3.15% and R3 = 2.22% per 14 days, and for 2013 it was R1 = 1.24%, R2 = 2.45% and R3 = 2.13% per 14 days;the apparent infection rates for 2010 were rR1 = 0.0003/day, rR2 = 0.0003/day and rR3 = 0.0003/day, and for 2013 they were rR1 = 0.0003/day, rR2 = 0.0004/day and rR3 = 0.0003/day. These values are characteristic of monocyclic epiphytic fungi such as F. oxysporum.
文摘The established culture of gametophytes of the red alga Pyropia yezoensis (TU-1) is superficially colonized by epiphytic bacteria. By 16S rRNA sequencing, 6 bacterial species were identified, and a culturable bacterium, Neptunomonas sp. BPy-1, was isolated. The 16S rRNA sequences of BPy-1 showed 100% identity with that of Neptunomonas sp. 0536, a probiotic bacterium found in greenshell mussels in New Zealand. Physiological tests revealed that 22 characters were identical between BPy-1 and 0536, but that 4 characters differed. BPy-1 cannot grow in the artificial seawater used for the culture of gametophytes. BPy-1 can grow in the artificial seawater with ethanol or butanol but not in methanol or propanol. To determine the effect of BPy-1 on gametophyte growth, BPy-1 colonization was reduced by 80% using a multi-enzyme cleaner. Changing the cleaner concentration yielded two types of gametophytes, a compressed or callus-like form and a nearly normal form. BPy-1 promoted the growth of the treated gametophytes with relatively normal form, while it showed less effect on compressed gametophytes. These findings suggested that BPy-1 promotes the growth of damaged gametophytes but does not affect the development of normal gametophytes.
