Diversity of subaerial algae and cyanobacteria on tree bark in tropical mountain habitats

We report the species composition of subaerial epixylic algae and cyanobacteria from a South-East Asian mountain rainforest locality in Cibodas, West Java. Green algae (Trebouxiophyceae, Chlorophyceae, Trentepohliales) were dominant and Cyanobacteria were the second most frequent group. We specifically concentrated on the comparison of species composition of closed primary forest and open antropogenic spaces. Trentepohliales and Cyanobacteria dominated in open spaces with higher light intensities, whereas closed forest localities were dominated by trebouxiophycean coccal green algae. There was a significantly higher algal diversity in open spaces than in closed forest samples indicating the limiting effect of light on subaerial algal communities of closed tropical forests. A number of isolated strains and morphotypes probably represent undescribed taxa. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

Green algae in tundra soils affected by coal mine pollutions

Green algal communities were investigated in clean and pollution-impacted tundra soils around the large coal mine industrial complex of Vorkuta in the E. European Russian tundra. Samples were collected in three zones of open-cast coal mining with different degrees of pollution-impacted soil transformation. A total of 42 species of algae were found in all zones. The species richness decreased from 27 species in undisturbed zones to 19 species in polluted zones. Under open-cast coal mining impacts the community structure simplified, and the dominant algae complexes changed. Algae that are typical for clean soils disappeared from the communities. The total abundance of green algae (counted together with Xanthophyta) ranged between 100–120 × 10³ (cells/g dry soils) in undisturbed zones and 0.5–50 × 10³ in polluted zones. Soil algae appear to be better indicators of coal mine technogenic pollution than flowering plants and mosses. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

典型红树林生态系统藻类多样性及其在生态过程中的作用

藻类是红树林生态系统重要的生物类群, 根据生态习性可分为浮游植物、底栖微藻和大型藻类三个生态类群, 它们在红树林生态系统生物多样性、初级生产、元素循环等方面起着重要作用。但在红树林生态系统中, 关注重点多集中在红树植物和动物, 对其中的藻类重视不够, 且多数研究集中在近20年以及亚洲的红树林区。事实上, 红树林生态系统藻类非常丰富, 其多样性研究有助于深入揭示红树林生态系统的结构与功能。本文介绍了红树林生态系统藻类的组成类群及其重要性, 重点对红树林区浮游植物、底栖硅藻和大型海藻的种类组成、地理分布及其与初级生产力、水质污染、元素循环、碳库形成等生态过程中的作用的研究动态和进展等进行了总结。根据已有研究, 红树林区浮游植物和底栖硅藻的种类数一般为几十到上百种, 其中硅藻在种类和数量上都占绝对优势, 它们是重要的初级生产者、饵料生物和水质污染指示生物; 红树林区底栖大型藻类主要由红藻、绿藻、褐藻、蓝藻组成, 绿藻的种类较多, 红藻在数量上占优势; 藻类是红树林湿地碳库的重要贡献者, 在红树林湿地生态系统碳汇和碳循环中起重要作用。红树林生态系统是个高度动态和异质的系统, 今后应加强红树林藻类多样性的长周期、大尺度变化及不同生境藻类的综合研究, 关注大陆径流和潮汐对藻类多样性和蓝碳的影响, 借助沉积物藻类记录, 探明红树林区藻类的长周期变化, 反演气候变化和人类活动对红树林生态系统的影响过程和机制。     

A metabarcoding comparison of windward and leeward airborne algal diversity across the Ko‘olau mountain range on the island of O'ahu,Hawai‘i1

Airborne algae from sites on the windward (n = 3) and leeward (n = 3) sides of the Ko‘olau Mountain range of O‘ahu, Hawai‘i, were sampled for a 16 d period during January and February 2015 using passive collection devices and were characterized using Illumina MiSeq sequencing of the universal plastid amplicon marker. Amplicons were assigned to 3,023 operational taxonomic units (OTUs), which included 1,189 cyanobacteria, 1,009 heterotrophic bacteria, and 304 Eukaryota (of which 284 were algae and land plants). Analyses demonstrated substantially more OTUs at windward than leeward O‘ahu sites during the sampling period. Removal of nonalgal OTUs revealed a greater number of algal reads recovered from windward (839,853) than leeward sites (355,387), with the majority of these being cyanobacteria. The 1,234 total algal OTUs included cyanobacteria, diatoms, cryptophytes, brown algae, chlorophyte green algae, and charophyte green algae. A total of 208 algal OTUs were identified from leeward side samplers (including OTUs in common among samplers) and 1,995 algal OTUs were identified from windward samplers. Barcoding analyses of the most abundant algal OTUs indicated that very few were shared between the windward and leeward sides of the Ko‘olau Mountains, highlighting the localized scale at which these airborne algae communities differ. Back trajectories of air masses arriving on O‘ahu during the sampling period were calculated using the NOAA HY‐SPLIT model and suggested that the sampling period was composed of three large‐scale meteorological events, indicating a diversity of potential sources of airborne algae outside of the Hawaiian Islands.     

Phylogenetic and morphological characterisation of the green algae infesting blue mussel Mytilus edulis in the North and South Atlantic oceans

Blue mussels Mytilus edulis with shell deformations and green pustules containing parasitic algae were collected at 3 coastal sites (Bur?y, Norway; Bockholm, Denmark; Goose Green, Falkland Islands). A comparative study, including mussel histopathology, algal morphology, ultrastructure and phylogenetic position was performed. Green pustules were mainly located in the posterior portion of the mantle and gonad tissues and the posterior adductor muscle. Electron microscopy confirmed the presence of algal cells with similar morphology to Coccomyxa parasitica. Algae were oval shaped with a single nucleus and chloroplast, 1 or 2 mitochondria and a dense granular cytoplasm with a lipid inclusion body, Golgi apparatus and small vesicles. Partial small subunit (SSU) rRNA phylogeny confirmed the inclusion of parasitic algae into the Coccomyxa clade. However, the sequence identity between almost full SSU rRNA sequences of parasitic algae and others in this clade yielded an unexpected result. Green algae from mussels were distant from C. parasitica Culture Collection of Algae and Protozoa (CCAP) strain 216/18 (94% identity), but very similar (99% identity) to C. glaronensis (a lichen endosymbiont) and green endophytes from the tree Ginkgo biloba. The CCAP strain 216/18 was a sister sequence to Nannochloris algae, far from the Coccomyxa clade. These results suggest a misidentification or outgrowth of the original CCAP strain 216/18 by a different 'Nannochloris-like' trebouxiophycean organism. In contrast, our sequences directly obtained from infested mussels could represent the true C. parasitica responsible for the green pustules in blue mussels.     

Phototrophic biofilms on the interior walls of concrete Iterson-type cooling towers

Algae and cyanobacteria form noticeable biofilms in the open spaces of natural draught cooling towers. In spite of this, our knowledge of these communities is still poor. During this study, phototrophic biofilms of seven cooling towers at four different plants in the Czech Republic were collected and studied in order to obtain information on the composition of the communities of these biofilms. Fresh material and cultures of collected material were analyzed with light microscopy. Twenty-five cyanobacterial and four algal taxa were found.     

Microbial Assemblages in Soil Microbial Succession After Glacial Retreat in Svalbard (High Arctic)

Microbial community composition (cyanobacteria and eukaryotic microalgae abundance and diversity, bacterial abundance, and soil respiration) was studied in subglacial and periglacial habitats on five glaciers near Ny-Alesund, Svalbard (79 degrees N). Soil microbial communities from nonvegetated sites (subglacial, recently deglaciated, and cryoconite sediments) and sites with plant cover (deglaciated some hundreds of years ago) were analyzed. Physicochemical analyses (pH, texture, water content, organic matter, total C and N content) were also performed on the samples. In total, 57 taxa of 23 genera of cyanobacteriaand algae were identified. Algae from the class Chlorophyceae (25 species) and cyanobacteria (23 species) were richest in biodiversity. The numbers of identified species in single habitat types were 23 in subglacial, 39 inbarren, 22 in cryoconite, and 24 in vegetated soils. The highest cyanobacterial and algal biovolume and cell numbers, respectively, were present in cryoconite (13x10(4) microm3 mg-1 soil and 508 cells per mg of soil), followed by barren (5.7x10(4) and 188), vegetated (2.6x10(4) and 120), and subglacial (0.1x10(4) and 5) soils. Cyanobacteria prevailed in all soil samples. Algae (mainly green algae) were present only as accessory organisms. The density of bacteria showed a slightly different trend to that of the cyanobacterial and algal assemblages. The highest number of bacteria was present in vegetated (mean: 13,722x10(8) cells per mg of soil dry wt.), followed by cryoconite (3802x10(8)), barren (654x10(8)), and subglacial (78x10(8)) soils. Response of cyanobacteria and algae to physical parameters showed that soil texture and water content are important for biomass development. In addition, it is shown that nitrogen and water content are the main factors affecting bacterial abundance and overall soil respiration. Redundancy analysis (RDA) with forward selection was used to create a model explaining variability in cyanobacterial, algal, and bacterial abundance. Cryoconites accounted for most of the variation in cyanobacteria and algae biovolume, followed by barren soils. Oscillatoriales, desmids, and green coccoid algae preferred cryoconites, whereas Nostocales and Chroococcales occurred mostly in barren soils. From the data obtained, it is evident that of the studied habitats cryoconite sediments are the most suitable ones for the development of microbial assemblages. Although subglacial sediments do not provide as good conditions as cryoconites, they support the survival of microbial communities. Both mentioned habitats are potential sources for the microbial recolonization of freshly deglaciated soil after the glacier retreat.     

Occurrence of airborne algae within the township of Bukit Jalil in Kuala Lumpur,Malaysia

There have been relatively few studies on airborne algae although they are known to have health implications. The aim of this study was to conduct a survey on the distribution of airborne algae within Bukit Jalil in Kuala Lumpur, Malaysia. The sampling sites included a quiet residential area, a busy area with high human movement, a highway with heavy traffic, small roads with low traffic, a golf course, two hilly areas, and the man-made lake, Tasik Komanwel. Soils were also collected from these sites when possible. Results based on cultured samples showed that cyanobacteria were the dominant airborne algae, with a total of eight species identified. The dominant species was Phormidium tenue while other airborne algae found included P. retzii, Nostoc commune, and N. linckia. The sites with high percentage occurrence of airborne algae were near the animal holding facility of the International Medical University and the Light Railway Transit station. Human movement could be an important factor affecting the occurrence of airborne algae. A very low occurrence of airborne algae was recorded at the sites around the lake area. Some of the airborne algae were also found in the soil samples, suggesting that the algae could originate from the soil.     

Airborne dispersal of antarctic terrestrial algae and cyanobacteria

The dispersal of algae and cyanobacteria at three Antarctic fellfield sites was investigated using microscopic and culture analysis of samples from active and passive air samplers Intersite variation in the mean number of large algal propagules (>5 μm diameter) sampled was dependent on the niche space available for algal growth and the degree to which soil was exposed to desiccating influences, these factors could be related to the degree of maturity of the sue The numbers of large algal propagules were lowest at sites from which permanent snow cover had recently disappeared and highest at sites with developed soil circles but poorly developed moss and lichen flora Mature sites with diverse and developed moss and lichen flora produced intermediate numbers of algal propagules Propagules of multicellular algae, cyanobacteria and large-celled unicellular algae were found in the air at the end of the growing season of the respective algal groups as the soil surface dried This was the case for Prasiola crispa, Pmnularia borealis , snow algae and filamentous chlorophytes and cyanobacteria Dispersal of unicellular chlorophytes was greatest during the summer period and at sites with developed secondary flora, but also occurred at other sites and in association with small thaw events during winter Cultures were obtained from samples collected whilst an air mass that had originated in South America, deposited material on Signy Island This suggests that algal propagules have the ability to survive long-distance transport and potentially provide mocula for colonization of Antarctica as regional warming continues to expose fresh habitats     

Early stages of biofilm succession in a lentic freshwater environment

Initial events of biofilms development and succession were studied in a freshwater environment at Kalpakkam, East Coast of India. Biofilms were developed by suspending Perspex (Plexiglass) panels for 15 days at bimonthly intervals from January 1996 to January 1997. Changes in biofilm thickness, biomass, algal density, chlorophyll a concentration and species composition were monitored. The biofilm thickness, biomass, algal density and chlorophyll a concentration increased with biofilms age and colonization was greater during summer (March, May and July) than other months. The initial colonization was mainly composed of Chlorella vulgaris, Chlorococcum humicolo (green algae), Achnanthes minutissima, Cocconeis scutellum, C. placentula (diatoms) and Chroococcus minutus (cyanobacteria) followed by colonial green algae such as Pediastrum tetras, P. boryanumand Coleochaete scutata, cyanobacteria (Gloeocapsa nigrescens), low profile diatoms (Amphora coffeaeformis, Nitzschia amphibia, and Gomphonema parvulum) and long stalked diatoms (Gomphoneis olivaceumand Gomphonema lanceolatum). After the 10th day, the community consisted of filamentous green algae (Klebshormidium subtile, Oedogonium sp., Stigeoclonium tenue and Ulothrix zonata) and cyanobacteria (Calothrix elenkinii, Oscillatoria tenuis and Phormidium tenue). Based on the percentage composition of different groups in the biofilm, three phases of succession could be identified: the first phase was dominated by green algae, the second by diatoms and the third phase by cyanobacteria. Seasonal variation in species composition was observed but the sequence of colonization was similar throughout the study period.     

Meteorological factors affecting the diversity of airborne algae in an urban atmosphere

Aeroalgal sampling of Varanasi City, India, was done using a Tilak Rotorod sampler and exposing agarised Bold basal medium Petri plates during March 2003 to February 2005. Amongst the 34 airborne algal genera recorded, cyanobacteria dominated the aero-algal flora, followed by green algae and diatoms. The generic diversity of airborne algae as well as the constituting groups exhibited seasonal variation. The most favored period for the appearance of cyanobacteria in the air was summer, while winter favored green algae. Presence of diatoms was almost uniform throughout the year. The presence of algal particles in the air depended upon the abundance and dynamics of algal source and their release and dispersal in the atmosphere. Best model selection with Akaike information criteria indicated temperature, relative humidity, rainfall, wind velocity as the most important climatic factors determining algal diversity. These factors exert their effect both directly by influencing entrainment and dispersal of algae from the source, and indirectly by regulating the dynamics of the possible algal source (soil, water, plant body, wall and roof of the building) by supporting or inhibiting the algal growth. In a closed environment and at low altitude sampling site characteristic is also an important factor. Open area near to the countryside had maximal aero-algal diversity.     

Algal assemblage responses to acid mine drainage and steel plant wastewater effluent up and downstream of pre and post wetland rehabilitation

Algae give a time-integrated indication of specific water quality components and respond rapidly to water quality changes making them useful for biomonitoring purposes. Freshwater algae were employed to differentiate between water quality conditions up and downstream before and after wetland rehabilitation to determine the feasibility of wetland enlargement as a possible rehabilitation measure. Grootspruit valley bottom wetland, impacted by acid mine drainage, was severely degraded before restoration. Rehabilitation was done through redirection of water flow using concrete structures to enlarge the surface area by 9.4 ha. After wetland rehabilitation, pH values, suspended chlorophyll-a and alkalinity concentrations increased downstream, while electrical conductivity, sulphate, total suspended solids decreased up to 80%. Algae species diversity and richness corresponded with the improvement of water quality and also increased downstream after rehabilitation. Overall, results indicated an improvement in algal diversity and water quality after enlargement of the bottom wetland.     

Green algae in spruce forests in the north-east of European Russia

The green algal communities in podzolic soils under coniferous forest in N.E. European Russia were studied in areas that were subjected to different technogenic pollution intensities. Sixty-five green algal species belonging to 4 classes, 12 orders, 20 families and 27 genera were recorded. The algal communities in the investigated soils of the different type spruce phytocoenoses included from 15 to 38 taxa on one site. Indicator species were identified for background spruce forests (Chalmydomonas gelatinosa, Tetracystis aggregata, T. dissociata, Pseudopleurococcus botryoides, Myrmecia bisecta) and for aerotechnogenically polluted spruce forests (Actinochloris sphaerica). The results may be used for the monitoring of the ecological state of biota in soils under boreal forests of protected areas and spruce forests exposed to intense aerial technogenic pollution. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

Nutrient status,algal and cyanobacterial flora of six fresh water streams of Schirmacher Oasis,Antarctica

The algal and cyanobacterial flora and the chemical environment of six freshwater streams of Schirmacher Oasis, Antarctica were investigated. Over 30 species of algae, predominantly cyanobacteria (Cyanophyceae), were recorded. N₂-fixing species, both heterocystous and unicellular diazotrophs, contributed more than 50% to the counts and their dominance was greatest in the middle of the stream where nitrogen and other nutrients were low. Green algae and diatoms also contributed to the flora. The species composition varied between streams. Glacial and snow drift meltwater streams contained a distinctive community. Based on diversity indices, these streams could be classified into two clusters.     

Algae, macrofaunal assemblages and temperature: a quantitative approach to intertidal ecosystems of Iceland

Algae and the associated macrofauna in two Icelandic intertidal ecosystems under cold and warm influence, respectively, were studied with respect to algae-macrofauna relationships and a possible effect of temperature on community structure. Two sites in Iceland were selected, Sandgerdi ligthhouse (64°8′N 22°40′W) on the southwestern coast, and Grimsey Island (66°33′N 18°04′W), in the north, on the Arctic Circle, where sea temperature is considerably lower (5° approximately). The biomass of algae and the number of species of algae and macrofauna were higher in Sandgerdi than in Grimsey, and the patterns of diversity, evenness, biomass and abundance also differed between the sites. In the intertidal zone of Sandgerdi, a total of 28 species of algae and 45 species of macrofauna were identified whereas only 16 algal species and 27 macrofaunal species were found in Grimsey. Canonical correspondence analysis (CCA) using algal biomass as the environmental variable were conducted, and revealed significant relationships between algae composition and the associated macrofauna; some macrofauna taxa showed specific trophic or refuge relationships with algal species. According to the CCA, Corallina officinalis showed the highest correlation with macrofaunal assemblages in both study sites. However, correlations between macrofauna and other algae differed between Grimsey and Sandgerdi. The present study, together with additional observations in Greenland waters, shows a general decrease of species richness and diversity towards the north which may primarily be due to the temperature regime.     

Algal and Cyanobacterial Biofilms on Calcareous Historic Buildings

Major microorganisms in biofilms on external surfaces of historic buildings are algae, cyanobacteria, bacteria, and fungi. Their growth causes discoloration and degradation. We compared the phototrophs on cement-based renderings and limestone substrates at 14 historic locations (47 sites sampled) in Europe and Latin America. Most biofilms contained both cyanobacteria and algae. Single-celled and colonial cyanobacteria frequently constituted the major phototroph biomass on limestone monuments (32 sites sampled). Greater numbers of phototrophs, and especially of algae and of filamentous morphotypes, were found on cement-based renderings (15 sites), probably owing to the porosity and small pore size of the latter substrates, allowing greater entry and retention of water. All phototrophic groups were more frequent on Latin American than on European buildings (20 and 27 sites, respectively), with cyanobacteria and filamentous phototrophs showing the greatest differences. The results confirm the influence of both climate and substrate on phototroph colonization of historic buildings. Received: 7 March 2002 / Accepted: 8 April 2002     

Species associations and metal contents of algae from rivers polluted by heavy metals

SUMMARY. The algal flora of the Rivers Hayle and Gannel. whieh drain copper and lead mining regions of Cornwall, are described and compared. Although fluctuations in the rarer members of the algal communities were observed, the dominant filamentous algae at most sites did not change over the year of study. Both the total algal abundance and the number of species were depressed at high metal sites. Associations of species that were evident in field samples were confirmed and correlated with water metal levels by principal component analysis. The close similarity between the flora of similar sites on the copper-polluted River Hayle and the lead-polluted River Gannei implies that the degree of metal pollution, rather than the polluting metal per se, determines the species present. All mine sites were characterized by a Microspora -community whereas a Zygnemales community of Spirogyra and Mougeotia species was typical of low metal pollution. Moderately polluted sites downsteam of the mines had an intermediate flora of Zygnemaies, Microsporales. Ulotrichales and gelatinous Volvocales and Tetrasporales species. No species could be said to invariably indicate metal pollution; the most abundant species at highly contaminated sites were also those with the widest distributions. Field samples of filamentous algae (mainly Spirogyra, Zygogonium, Mougeotia and Microspora species) contained metal concentrations several orders of magnitude greater than ambient levels. For copper and iron, both algal metal contents and concentration ratios (μg g-1 algae/μg ml-1 water) were positive functions of water metal levels, although algal iron appeared to plateau at water concentrations of about 1 mg ml-1. Algal lead concentrations, but not the concentration ratios, also were positively correlated with water lead levels. Thus, for these three metals, the algal metal contents were indicative of ambient conditions. In contrast, algal zinc concentrations were nearly constant and consequently the concentration ratios for this metal were inversely related to water levels. This result suggests that unlike the uptake of other metals, uptake of zinc by these aigae may be strictly regulated.     

Photobiont association and genetic diversity of the optionally lichenized fungus Schizoxylon albescens

The fungus Schizoxylon albescens occurs both as lichen and as saprobe. Lichenized colonies grow on the bark of Populus tremula; saprotrophic morphs grow on dead Populus branches. We wanted to (1) test whether lichenized and saprotrophic S. albescens are genetically distinct, (2) investigate photobiont association and diversity, (3) investigate the interactions between fungi and algae that occur during co-cultivation and (4) test whether Schizoxylon shows algal selectivity during lichenization. Fungal and algal genetic diversity were investigated for three markers. Algae from lichenized thalli were isolated in axenic cultures, and isolate sequence diversity was compared with algae amplified directly from thallus fragments. Co-culture experiments of fungi and algae were performed to study the morphological interaction patterns. Two distinct phylogenetic units are revealed in S. albescens, which are interpreted as phenotypically cryptic species. The algae are related to Coccomyxa and Pseudococcomyxa, and form two distinct sister clades separating samples isolated in cultures from those amplified directly from thallus fragments, indicating that more easily cultured strains of algae are not necessarily major components of the lichens. Schizoxylon albescens interacts with isolated algal strains, similar to fungal-Coccomyxa symbioses in nature. As the system is maintained without difficulty in culture, it can potentially be an easily controlled lichen symbiosis study system under laboratory conditions.     

Soil Algae in Brown Coal and Lignite Post-Mining Areas in Central Europe (Czech Republic and Germany)

Algal communities were investigated in two contrasting chronosequences established on reclaimed spoils in the west Bohemian brown coal mining district near Sokolov (Czech Republic) and in the Lusatian lignite mining district near Cottbus (Germany). The Sokolov chronosequence was characterized by tertiary cypric clay substrate, afforestation with Alnus glutinosa (L.) Gaertn., and high pH of deposited spoil material, Cottbus chronosequence by tertiary carboniferous and pyritic sand of extremely low pH ameliorated by fly ash, and afforestation with Pinus sylvestris L. and P. nigra Arnold. A total of 122 species of algae was found in both areas. Although the same species number (80) was identified from Sokolov and Cottbus, both proportion of individual algal groups and species composition were different. Green algae prevailed in both areas, but in Sokolov cyanobacteria and diatoms were also quite diverse, and in younger sites they were also abundant. Total abundance of algae ranged mostly between 10⁴–10⁷ cells/g dry soil, and was one order higher in Cottbus than in Sokolov. Species number was high in young sites, decreased with increasing age, and was the lowest in control forests. In Sokolov, the highest abundance was recorded in the youngest alder plantation. In Cottbus, sludge and compost fertilization used in the youngest pine plantations resulted in rapid formation of visible algal crusts dominated by Klebsormidium crenulatum (Kütz) Lokhorst.     

环境汞污染对藻类的毒性效应及其影响因素

综述了汞污染对藻类的毒性效应及影响因素。水环境中汞主要以元素汞、无机汞和有机汞3种形式存在。藻类吸附汞主要分为胞外的快速吸附和胞内的缓慢富集,在安全浓度内,金属汞对藻生长有一定的促进作用,随着浓度增大,抑制藻生长或致死。汞进入藻体细胞后,藻类为了存活会产生一系列保护机制。藻类对汞的排斥和排出作用可能就是对汞耐性的一种重要机制。藻类也可以通过多种方式减少汞进入藻类细胞,以及通过与其他物质结合汞使其排出胞外。温度、pH、生物学因素等影响重金属对藻类的毒性作用。并就藻类对汞耐性和适应机理、利用藻类修复和监测重金属污染、藻类响应汞胁迫的信号转导途径及其保护机制等未来研究领域进行了展望。