Comparative expression analysis of heavy metal ATPase subfamily genes between Cd-tolerant and Cd-sensitive turnip landraces

The heavy metal ATPase(HMA)subfamily is mainly involved in heavy metal(HM)tolerance and transport in plants,but an understanding of the definite roles and mechanisms of most HMA members are still limited.In the present study,we identified 14 candidate HMA genes named BrrHMAl—BrrHMA8 from the turnip genome and analyzed the phylogeny,gene structure,chromosome distribution,and conserved domains and motifs of HMAs in turnip(Brassica rapa var.rapa).According to our phylogenetic tree,the BrrHMAs are divided into a Zn/Cd/Co/Pb subclass and Cu/Ag subclass.The BrrHMA members show similar structural characteristics within subclasses.To explore the roles of BrrHMAs in turnip,we compared the gene sequences and expression patterns of the BrrHMA genes between a Cd-tolerant landrace and a Cd-sensitive landrace.Most BrrHMA genes showed similar spatial expression patterns in both Cd-tolerant and Cd-sensitive turnip landraces;some BrrHMA genes,however,were differentially expressed in specific tissue in Cd-tolerant and Cd-sensitive turnip.Specifically,BrrHMA genes in the Zn/Cd/Co/Pb subclass shared the same coding sequence but were differentially expressed in Cd-tolerant and Cd-sensitive turnip landraces under Cd stress.Our findings suggest that the stable expression and up-regulated expression of BrrHMA Zn/Cd/Co/Pb subclass genes under Cd stress may contribute to the higher Cd tolerance of turnip landraces.     

Growth promotion of Suillus luteus by adenosine in vitro

In this work, adenosine has been shown to stimulate Suillus luteus mycelial growth, branching, and aggregates on solid substrate. Adenosine promoted S. luteus mycelial growth and branching, and the fungus responded significantly at a concentration as low as 0.01 mg/ml. The highest mycelial biomass and density of three strains were observed at 0.16 mg/ml in SNP-20, 0.08 mg/ml in SAF-501, and 0.16 mg/ml in PT-501. Adenosine enhanced mycelial aggregate at concentration of 0.02 mg/ml in SNP-20. The study suggests that adenosine promotes S. luteus mycelial growth, branching, and aggregation. Thus, it may be a good candidate as a biological elicitor of mycelial growth for S. luteus.     

A case of mushroom poisoning from Suillus luteus

Suillus luteus, although often eaten, can cause illness. We describe the sickness and suggest removal of the cuticle before eating.     

共培养条件下绿木霉对褐环乳牛肝菌产酶的诱导效应

为了探讨绿木霉与褐环乳牛肝菌的互作机理,在体外共培养条件下,采用光学显微镜和扫描电镜对二者生长重叠部分进行体外观察,发现二者生长无相互影响,在营养生长方面几乎不存在竞争关系。为进一步揭示绿木霉与褐环乳牛肝菌的互作机制,采用体外诱导和生物化学等方法,向褐环乳牛肝菌发酵液中加入灭活绿木霉菌丝诱导物,每天对发酵液中的多酚氧化酶、几丁质酶、漆酶和中性蛋白酶等酶活性进行检测。试验结果表明,绿木霉诱导褐环乳牛肝菌产漆酶能力最强;在整个共培养过程中,多酚氧化酶和漆酶活力始终处于较高水平,在诱导培养第6天,这两种酶活性升至最高,分别达到25.2U/mL和1 580U/mL;灭活绿木霉菌丝对褐环乳牛肝菌几丁质酶的诱导具有“瞬时性”,在诱导培养第2天即检测到较高的几丁质酶活性;中性蛋白酶的活性变化基本上呈先上升后下降的规律,且能增大褐环乳牛肝菌中性蛋白酶的固有产量,形成“叠加效果”。综上所述,绿木霉对褐环乳牛肝菌几乎不存在营养竞争关系,但其灭活菌丝体对褐环乳牛肝菌发酵液的多种酶活性存在诱导增效作用。     

Genetic variation and heavy metal tolerance in the ectomycorrhizal basidiomycete Suillus luteus

Twenty-one isolates of the ectomycorrhizal fungus Suillus luteus were screened for their tolerance to the heavy metals Zn, Cd, Cu and Ni, measured as inhibition of radial growth and biomass production. Two populations from even-aged pine stands were investigated: 10 isolates were obtained from an area polluted with high levels of Zn, Cd and Cu, and 11 isolates were obtained from a control population located in a nearby unpolluted area. RFLP patterns of the internal transcribed spacer region of the isolates confirmed the morphological identification of the carpophores. All isolates were maintained on basic medium without elevated metals to avoid phenotypically acquired metal tolerance. The in vitro Zn and Cd tolerance of the S. luteus isolates from the polluted habitat were significantly higher than the tolerances measured in the isolates from the nonpolluted site. This observation suggests that the elevated soil metal concentrations might be responsible for the evolution of adaptive Zn and Cd tolerance. Tolerance was maintained in an isolate not exposed to elevated metals for 3 yr. The two S. luteus populations did not differ in tolerance to Cu and Ni. The mechanisms for the adaptive Zn and Cd tolerance are not identical as there was no correlation between response to the two metals; the most Zn-tolerant isolate was the most sensitive for Cd in the metal-tolerant population. Zinc did not accumulate in basidiocarp tissue, whereas Cd levels in basidiocarps were significantly higher in the population on the polluted site. Inter-simple sequence-repeat fingerprints showed that 90% of the isolates were from different individuals. The genetic variation in the population from the unpolluted site was considerably larger than that observed at the polluted site.     

Genetic structure of Suillus luteus populations in heavy metal polluted and nonpolluted habitats

The genetic structure of populations of the ectomycorrhizal basidiomycete Suillus luteus in heavy metal polluted and nonpolluted areas was studied. Sporocarps were collected at nine different locations and genotyped at four microsatellite loci. Six of the sampling sites were severely contaminated with heavy metals and were dominated by heavy metal-tolerant individuals. Considerable genetic diversity was found within the geographical subpopulations, but no reduction of the genetic diversity, current or historic, was observed in subpopulations inhabiting polluted soils. The genetic differentiation between the geographical subpopulations was low, and no evidence for clustering of subpopulations from polluted soils vs. subpopulations from nonpolluted soils was found. These results indicate that heavy metal pollution has a limited effect on the genetic structure of S. luteus populations, and this may be due to the high frequency of sexual reproduction and extensive gene flow in S. luteus, which allows rapid evolution of the tolerance trait while maintaining high levels of genetic diversity.     

A new ceramide from Suillus luteus and its cytotoxic activity against human melanoma cells

A new phytosphingosine-type ceramide, suillumide (1), was isolated from the EtOH extract of the basidiomycete Suillus luteus (L.) S. F. Gray, along with ten known compounds: ergosta-4,6,8(14),22-tetraen-3-one, ergosterol, ergosterol peroxide, suillin, (E)-3,4,5-trimethoxycinnamic alcohol, 5 alpha,6 alpha-epoxyergosta-8,22-diene-3beta,7 beta-diol, (R)-1-palmitoylglycerol, ergosta-7,9(11),22-triene-3beta,5 alpha,6 beta-triol, cerevisterol, and 4-hydroxybenzoic acid. The structure of 1 was determined on the basis of spectroscopic and mass-spectrometric analyses, as well as by chemical methods. Compound 1 and its synthetic diacetyl derivative 2 were tested for their cytotoxic activities against the human melanoma cell line SK-MEL-1. Both drugs showed IC(50) values of ca. 10 microM after 72 h of exposure.     

褐环乳牛肝菌对樟子松和油松根际土壤真菌多样性的影响

为了解褐环乳牛肝菌Suillus luteus对樟子松Pinus sylvestris var. mongolica和油松Pinus tabulaeformis根际土壤真菌群落结构的影响,采用Illumina MiSeq高通量测序,对两种松树接种S. luteus与对照组的根际土壤真菌群落结构进行研究。结果显示,4个样品共获得原始序列347 681条,归为5个真菌门。综合各土壤样品真菌Alpha多样性指数及OTUs-Venn图,发现接种S. luteus后樟子松和油松根际土壤真菌相对丰度与对照存在一定差异。群落结构分析表明,接种S. luteus提高了樟子松和油松根际土壤担子菌和壶菌的相对丰度,抑制了子囊菌门真菌。优势属由原来的Geopora转变为Suillus。通过PCA分析与NMDS分析发现接种S. luteus后樟子松和油松根际土壤真菌群落差异性增加,且接种S. luteus后樟子松根际土壤真菌群落结构相似性显著高于油松根际土壤真菌群落结构相似性。接种S. luteus的樟子松和油松土壤真菌丰富度降低、多样性增加,接种S. luteus改变了樟子松和油松根际土壤真菌群落结构和优势真菌种群。试验结果为樟子松和油松促生真菌菌种筛选和育苗工作提供了依据。     

Physiological Responses of Pinus sylvestris var. Mongolica Seedlings to the Interaction Between Suillus luteus and Trichoderma virens

The effects of the interaction between Suillus luteus (L.) Roussel and Trichoderma virens (J.H. Mill., Giddens & A.A. Foster) Arx on Pinus sylvestris var. mongolica Litv. were studied using plant physiology, mycorrhizal science, forest pathology, and biochemistry. Seedling growth and physiological parameters were determined, including the colonization rate of mycorrhizal fungi, biomass, root activity, photosynthetic pigment content, soluble protein content, antioxidant enzyme activities, rhizosphere soil enzyme activities, and protective enzyme activities. In addition, an optimal resistance system involving T. virens, mycorrhizal fungus (S. luteus), and P. sylvestris var. mongolica seedlings was constructed. Synergies between S. luteus and T. virens were observed, and most of the parameters of P. sylvestris var. mongolica seedlings inoculated with S. luteus 30 days + T. virens were higher than other treatments. After three months, when compared the control, the S. luteus 30 days + T. virens treatment gave increases in height (42.3 %); collar diameter (66.7 %); fresh weight (54 %); dry weight (50 %); soluble protein content (69.86 %); root activity (150 %); chlorophyll a (77.6 %); chlorophyll b (70.5 %); carotenoids (144 %); CAT activity (876.9 %); POD activity (268.3 %); SOD activity (66.18 %); β-1,3-glucanase activity (125.8 %); chitinase activity (40 %); rhizosphere soil catalase activity (97.8 %); and phosphatase activity (266.7 %). These results indicate that there may be a stimulating factor between S. luteus and T. virens when they are inoculated together (S. luteus 30 days + T. virens).     

基于高通量测序的玉米象转录组分析

玉米象Sitophilus zeamais是一种世界性的储粮害虫,但其基因信息尚不完善.本研究利用高通量测序平台Illumina HiSeq TM2000对玉米象成虫进行转录组测序,总计获得64358条unigenes,总长度39481752 bp,最短201 bp,最长29046 bp,平均长度613 bp.将unigenes序列在7大数据库Nr、GO、Swissprot、KOG、Pfam、KEGG、TrEMBL中进行注释,分别有25271、20747、16477、12060、9471、3370、25500条unigenes获得注释.通过GO功能分类,共有20747条unigenes在GO数据库中生物学过程、细胞组分、分子功能3大类68个亚类功能组中找到对应.KOG结果显示,12606条unigenes归到25个基因家族.通过KEGG代谢通路分析,共有3370条unigenes被注释,分别归属于细胞进程、环境信息进程、遗传信息进程、新陈代谢和有机体系统5大类代谢途径,共33个亚类274个功能通路.进一步的数据分析,共鉴定出146081个SNP位点和5002个简单序列重复(SSR)位点.本研究获得的玉米象转录组信息,为玉米象的功能基因挖掘提供了重要的信息资源.     

基于高通量测序的麦红吸浆虫转录组分析

麦红吸浆虫Sitodiplosis mosellana(Gehin)是一种世界性的小麦害虫。为获得其转录组信息,本研究采用新一代高通量测序技术Illumina HiSeq TM 2000对麦红吸浆虫成虫转录组进行测序。共获得转录组样本数据量为27.88 G,经分析共获得59257个Unigenes,总长度49861164 bp,最短20 bp,最长29282 bp,平均长度841 bp。将Unigenes序列与NR、NT、Swiss-Prot、KEGG、GO和KOG数据库进行比对(e≤10-10),共获得95029个结果。通过GO功能分类,共有19584个Unigenes在GO数据库中细胞组分、分子功能和生物学过程等3大类50个功能组中找到对应。与KOG数据库进行比对,共有11279个麦红吸浆虫Unigenes被注释,按功能大致可分为26类。通过KEGG pathways分析,共有9110个麦红吸浆虫Unigenes被注释,分别归属于细胞进程、环境信息进程、遗传信息进程、新陈代谢和有机体系统5大类代谢途径,主要包括细胞生长与死亡、细胞运动、信号转导、能量代谢等32类代谢途径。CDS预测发现30088条序列可被编码,占全部基因的50.78%。SSR位点查找发现,在59257个Unigenes中共找到36323个SSR位点,发生率为61.30%。本研究获得的巨大的麦红吸浆虫转录组信息,为麦红吸浆虫的功能基因挖掘提供了重要的信息资源。     

褐环乳牛肝菌对樟子松生长的调控——影响激素和代谢产物含量

为了进一步探究褐环乳牛肝菌对樟子松苗木生长的促进机制,利用生物化学和植物生理学等研究方法,在前期研究基础上对2年生沙地樟子松苗木施加褐环乳牛肝菌液体菌剂,并在2个月后对苗木各部分生长状态、生长相关激素、抗逆性代谢产物进行检测。结果表明：褐环乳牛肝菌可以通过升高樟子松IAA和GA含量促进樟子松苗木的生长。其中,对樟子松根系中IAA含量影响最为显著,接菌苗木根中IAA含量比未接菌苗木根中IAA含量高85%以上;与此结果相反,褐环乳牛肝菌可以降低樟子松苗木ABA含量,通过ABA含量变化调控IAA含量,进而调控根系的生长;除此之外,褐环乳牛肝菌可以调控樟子松苗木甜菜碱和黄酮化合物的含量。未接菌苗木的甜菜碱在根、茎、叶中的含量分别比接菌苗木高46%、26%和23%,说明接菌苗木在受环境的影响方面相较于未接菌苗木低。接菌处理可以显著提高樟子松苗木根部黄酮化合物含量。本研究结果可以为今后进一步研究提供数据借鉴,同时也可以为辽西半干旱地区森林健康调控与褐环乳牛肝菌科学应用于当地造林提供科学依据。