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1.
The ability of arbuscular mycorrhizal (AM) fungi from a metal-tolerant plant (Viola calaminaria, violet) to colonise and reduce metal uptake by a non-tolerant plant (Trifolium subterraneum, subterranean clover) in comparison to a metal-tolerant AM fungus isolated from a non-tolerant plant was studied. AM spores
from the violet rhizosphere and from violet roots were characterised by polymerase chain reaction (PCR) amplification of the
SSU rDNA, and sequencing. Subterranean clover was grown in pots containing a soil supplemented with Cd and Zn salts and inoculated
either with a mixture of spores extracted from the violet rhizosphere or with spores of a Cd-tolerant Glomus mosseae P2 (BEG 69), or non-inoculated. The diversity of fungi, including AM fungi, colonising clover roots was assessed and analysed
using terminal-restriction fragment length polymorphism. At least four different Glomus species were found in the violet rhizosphere. After 8 weeks in a growth chamber, colonisation of clover roots with spores
from the violet rhizosphere increased Cd and Zn concentrations in clover roots without significantly affecting the concentrations
of metals in the shoot and plant growth. G. mosseae P2 reduced plant growth and slightly increased the Cd concentration. Only one AM fungus (Glomus b) from the violet rhizosphere colonised clover roots, but other fungi were present. AM fungi from heavy metal-contaminated
soils and associated with metal-tolerant plants may be effective in accumulating heavy metals in roots in a non-toxic form.
Accepted: 7 July 2000 相似文献
2.
Analysis of arbuscular mycorrhizal (AM) fungal diversity through morphological characters of spores and intraradicular hyphae
has suggested previously that preferential associations occur between plants and AM fungi. A field experiment was established
to investigate whether AM fungal diversity is affected by different host plants in upland grasslands. Indigenous vegetation
from plots in an unimproved pasture was replaced with monocultures of either Agrostis capillaris or Lolium perenne. Modification of the diversity of AM fungi in these plots was evaluated by analysis of partial sequences in the large subunit
(LSU) ribosomal RNA (rDNA) genes. General primers for AM fungi were designed for the PCR amplification of partial sequences
using DNA extracted from root tissues of A. capillaris and L. perenne. PCR products were used to construct LSU rDNA libraries. Sequencing of randomly selected clones indicated that plant roots
were colonised by AM fungi belonging to the genera Glomus, Acaulospora and Scutellospora. There was a difference in the diversity of AM fungi colonising roots of A. capillaris and L. perenne that was confirmed by PCR using primers specific for each sequence group. These molecular data suggest the existence of a
selection pressure of plants on AM fungal communities. 相似文献
3.
Baoming Ji Catherine A. Gehring Gail W. T. Wilson R. M. Miller Lluvia Flores‐Rentería Nancy Collins Johnson 《Molecular ecology》2013,22(9):2573-2587
Arbuscular mycorrhizal (AM) fungi are widespread root symbionts that often improve the fitness of their plant hosts. We tested whether local adaptation in mycorrhizal symbioses would shape the community structure of these root symbionts in a way that maximizes their symbiotic functioning. We grew a native prairie grass (Andropogon gerardii) with all possible combinations of soils and AM fungal inocula from three different prairies that varied in soil characteristics and disturbance history (two native prairie remnants and one recently restored). We identified the AM fungi colonizing A. gerardii roots using PCR amplification and cloning of the small subunit rRNA gene. We observed 13 operational taxonomic units (OTUs) belonging to six genera in three families. Taxonomic richness was higher in the restored than the native prairies with one member of the Gigaspora dominating the roots of plants grown with inocula from native prairies. Inoculum source and the soil environment influenced the composition of AM fungi that colonized plant roots. Correspondingly, host plants and AM fungi responded significantly to the soil–inoculum combinations such that home fungi often had the highest fitness and provided the greatest benefit to A. gerardii. Similar patterns were observed within the soil–inoculum combinations originating from two native prairies, where five sequence types of a single Gigaspora OTU were virtually the only root colonizers. Our results indicate that indigenous assemblages of AM fungi were adapted to the local soil environment and that this process occurred both at a community scale and at the scale of fungal sequence types within a dominant OTU. 相似文献
4.
5.
一种改进的丛枝菌根染色方法 总被引:7,自引:0,他引:7
研究改进了Vierheilig等描述的AM菌根染色法:将根样于20%KOH溶液中60℃水浴透明40-120 min,5%醋酸酸化5min后,用5%醋酸墨水染色液(派克纯黑书写墨水Quink),于60℃水浴染色30 min,清水浸泡脱色(14h)后即可镜检。根皮层细胞内AM真菌的丛枝结构清晰可见,并且能够明确地分辨AM真菌与其它未知真菌。此外,Quink初染后,再经过SudanⅣ复染(60℃、60 min),70%乙醇脱色5min,暗隔真菌的透明菌丝内所积聚的脂类颗粒被SudanⅣ染上鲜红色,在复式显微镜下能够观察到此类透明菌丝在根皮层组织内的存在状况。采用甘油明胶为封固剂制片,根的染色效果可以保存长久。此项技术可以对同一种植物的多个根样进行同步的透明和染色处理,而且操作简便、低毒性、成本低廉、染色效果极佳,适用于野生和栽培草本植物AM菌根的染色和制片观察。 相似文献
6.
Exotic invasive plants can show strong plant–soil feedback responses, but little is known about time scales for significant changes in soil microbial communities to occur after invasion. Previous work has suggested that plant invasions can modify arbuscular mycorrhizal (AM) fungal community structure. However, there is a lack of understanding about how long it takes for these changes to develop. To test this we investigated temporal changes in AM fungal communities colonising the invasive plant Vincetoxicum rossicum (Apocynaceae). We hypothesised that AM fungal community structure would change in a particular direction during the invasion process. We collected soil from two sites with a long history of invasion by this plant, with each site having paired invaded and uninvaded plots. Soil from these plots was used in a glasshouse experiment to characterise AM fungal community structure in the roots of V. rossicum at different times throughout a simulated growing season. AM fungal community structure differed between invaded and uninvaded plots. However, contrasting with our hypothesis, AM fungal communities colonising V. rossicum growing in soil from uninvaded plots did not change towards those in plants growing in previously invaded soil. Our data suggest that changes to AM fungal communities in the presence of V. rossicum require longer than the first growing season after establishment to develop. 相似文献
7.
Identification of arbuscular mycorrhizal fungi in soils and roots of plants colonizing zinc wastes in southern Poland 总被引:8,自引:0,他引:8
Analysis of the community of arbuscular mycorrhizal (AM) fungi in roots of Fragaria vesca growing in a heavy metal contaminated site was carried out on a Zn waste site near Chrzanow (southern Poland). The waste
substratum was characterized by high contents of Pb, Zn, Cd, Cu and As, and by low levels of N, P and organic matter. Spores
of Glomales were isolated by wet sieving and DNA was isolated from individual spores. Nested polymerase chain reaction (PCR)
with taxon-specific primers was used to identify the species Glomus mosseae, Glomus intraradices and Glomus claroideum. Spores of other fungi were morphologically characterized and new taxon-discriminating molecular probes were developed for
two of them (Glomus sp. HM-CL4 and HM-CL5) based on variations in the large ribosomal subunit (25S rDNA). High sequence similarities were found
between Glomus sp. HM-CL4 and Glomus gerdemanii, and between Glomus sp. HM-CL5 and Glomus occultum. The designed primers were used to characterize the population of AM fungi colonizing the roots of F. vesca collected from the Zn waste site. The analysis, carried out on roots stained with trypan blue, showed that the most effective
colonizer was closely related to G. gerdemannii. G. claroideum and the G. occultum-like fungus were slightly less common whilst frequencies of G. intraradices and G. mosseae in roots were much lower. The analysis of mycorrhiza stained with rhodizoniate to localize heavy metal accumulation showed
that the stain does not influence the PCR reaction. Seventy percent of the root samples containing positively stained fungal
hyphae were found to be colonized by G. mosseae. The data obtained demonstrate the usefulness of nested PCR for studies carried out in polluted areas. It will enable selection
of AM fungi which are able to colonize plant roots under heavy metal stress conditions, as well as the identification of fungi
showing high in situ accumulation of potentially toxic elements.
Accepted: 7 July 2000 相似文献
8.
Ulf Grunwald Wenbing Guo Kerstin Fischer Stanislav Isayenkov Jutta Ludwig-Müller Bettina Hause Xiaolong Yan Helge Küster Philipp Franken 《Planta》2009,229(5):1023-1034
A microarray carrying 5,648 probes of Medicago truncatula root-expressed genes was screened in order to identify those that are specifically regulated by the arbuscular mycorrhizal
(AM) fungus Gigaspora rosea, by Pi fertilisation or by the phytohormones abscisic acid and jasmonic acid. Amongst the identified genes, 21% showed a common
induction and 31% a common repression between roots fertilised with Pi or inoculated with the AM fungus G. rosea, while there was no obvious overlap in the expression patterns between mycorrhizal and phytohormone-treated roots. Expression
patterns were further studied by comparing the results with published data obtained from roots colonised by the AM fungi Glomus mosseae and Glomus intraradices, but only very few genes were identified as being commonly regulated by all three AM fungi. Analysis of Pi concentrations in plants colonised by either of the three AM fungi revealed that this could be due to the higher Pi levels in plants inoculated by G. rosea compared with the other two fungi, explaining that numerous genes are commonly regulated by the interaction with G. rosea and by phosphate. Differential gene expression in roots inoculated with the three AM fungi was further studied by expression
analyses of six genes from the phosphate transporter gene family in M. truncatula. While MtPT4 was induced by all three fungi, the other five genes showed different degrees of repression mirroring the functional differences
in phosphate nutrition by G. rosea, G. mosseae and G. intraradices.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Localization of the 49-kDa apyrase (ATP diphosphohydrolase, EC3.6.1.5; DDBJ/EMBL/GenBank BAB40230) was investigated during
early stages of germination of pea (Pisum sativum L. var. Alaska) at the organ, tissue, cellular, and sub-cellular level using light-microscopical immunohistochemistry. Whole
mount tissues were immuno-reacted with anti-APY1 serum, pre-immune serum or anti-actin antibody for control. Antigen to the
anti-APY1 serum was not detected until 16 h after sowing (26 h after start of imbibition), when the antigen was detected throughout
the tissue, especially in the epidermis and cortex. At 35 h after sowing, the younger regions including the root tip and the
tip of the stele were more strongly stained than the control. Both, epidermal and cortical cells of the epicotyl and root
tip were stained. The stain was mainly localized in the cytoplasm and around nuclei in the apical meristem and the root tip,
while vacuoles and cell walls were not stained. At 62 h, there was major staining in the plumule, hook, and elongating regions
of the epicotyl and in the region between cotyledons and the epicotyl. After 84 h, lateral root primordia were stained. The
pre-immune serum showed virtually no staining while the anti-actin antibody reacted solely with the cytoplasm. Since the antigen
to the anti-APY1 serum was primarily found in the cytoplasm and around nuclei in elongating and differentiating tissues and
labeling declined in mature tissues, it is suggested that apyrases may play a role in growth and development of tissues, for
example, lateral roots. 相似文献
10.
Muravenko OV Yurkevich OY Bolsheva NL Samatadze TE Nosova IV Zelenina DA Volkov AA Popov KV Zelenin AV 《Genetica》2009,135(2):245-255
Karyotypes of species sects. Linum and Adenolinum have been studied using C/DAPI-banding, Ag-NOR staining, FISH with 5S and
26S rDNA and RAPD analysis. C/DAPI-banding patterns enabled identification of all homologous chromosome pairs in the studied
karyotypes. The revealed high similarity between species L. grandiflorum (2n = 16) and L. decumbens by chromosome and molecular markers proved their close genome relationship and identified the chromosome number in L. decumbens as 2n = 16. The similarity found for C/DAPI-banding patterns between species with the same chromosome numbers corresponds with
the results obtained by RAPD-analysis, showing clusterization of 16-, 18- and 30-chromosome species into three separate groups.
5S rDNA and 26S rDNA were co-localized in NOR-chromosome 1 in the genomes of all species investigated. In 30-chromosome species,
there were three separate 5S rDNA sites in chromosomes 3, 8 and 13. In 16-chromosome species, a separate 5S rDNA site was
also located in chromosome 3, whereas in 18-chromosome species it was found in the long arm of NOR-chromosome 1. Thus, the
difference in localization of rDNA sites in species with 2n = 16, 2n = 30 and 2n = 18 confirms taxonomists opinion, who attributed these species to different sects. Linum and Adenolinum, respectively. The
obtained results suggest that species with 2n = 16, 2n = 18 and 2n = 30 originated from a 16-chromosome ancestor. 相似文献
11.
Hematoxylin staining as a phenotypic index for aluminum tolerance selection in tropical maize (Zea mays L.) 总被引:6,自引:0,他引:6
G. M. A. Cançado L. L. Loguercio P. R. Martins S. N. Parentoni E. Paiva A. Borém M. A. Lopes 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(5):747-754
Hematoxylin staining is an early indicator of Aluminum (Al) toxicity effects on the apices of young, developing roots grown
in nutrient solution. In this work, the potential of this technique as a reliable and reproducible phenotypic index for Al
tolerance in tropical maize genotypes was assessed, with its performance systematically compared to two other parameters widely
used in breeding programs – relative seminal-root length (RSRL) and net seminal-root length (NSRL). Seeding roots from contrasting
genotypes for Al sensitivity stained remarkably different after 24- and 48-h and 7-day exposures to 222 μM Al in nutrient solution, with the Al-dye complex being detected in both the outer (epidermis) and inner (cortex) portions
of the roots from the sensitive cultivar. Hematoxylin staining was compared to the RSRL and NSRL parameters using 20 families
from the third generation of selfing (S3) following the cross between two contrasting inbred lines that had been previously
classified by the RSRL index in an independent procedure. The coloration technique showed the highest capacity to discriminate
among tolerant and sensitive genotypes and displayed significant correlation coefficients to the other two indexes. Evaluation
of the results from diallel crosses involving nine inbred lines proved that hematoxylin staining was also particularly adequate
for identifying expressive hybrid vigor, as demonstrated by the general (GCA) and specific (SCA) combining ability estimates
obtained by using the three indexes simultaneously. Hence, hematoxylin staining of Al-stressed root apices appears to be a
powerful tool to assist in Al-tolerance selection in tropical maize breeding programs.
Received: 21 January 1999 / Accepted: 1 February 1999 相似文献
12.
Takaaki Nishida Naoyuki Izumi Noboru Katayama Takayuki Ohgushi 《Population Ecology》2009,51(2):329-334
We examined effects of aboveground herbivory by spider mites (Tetranychus urticae) on colonization and activity of arbuscular mycorrhizal fungi (AMF; Gigaspora margarita) using potted plants (Lotus japonicus). We evaluated changes in arbuscular mycorrhizal (AM) association two ways: (1) conventional trypan blue staining of mycorrhizal
hyphae to examine AMF biomass in roots (mycorrhizal colonization) and (2) vital staining for a mycorrhizal enzyme (succinate
dehydrogenase, SDH) to examine mycorrhizal activity (SDH activity). Mycorrhizal colonization and SDH activity started to increase
4 days after aboveground herbivory, and returned to the initial levels in the absence of mite herbivory in 7 and 12 days,
respectively. These results suggest that the change in AM association in response to mite herbivory is a short-term response. 相似文献
13.
Quercus acutissima seedlings were cultivated in growth pouches and inoculated with Scleroderma verrucosum in order to assess the changes in polyphenol contents in epidermal cells during ECM development. Semithin sections stained
with metachromatic Toluidine Blue O (TBO) were compared among non-inoculated lateral roots, early mantled lateral roots, and
mycorrhizal roots with a mature mantle. Hyphae adhered closely or were embedded in mucilage-like materials on the epidermis.
Epidermal cells and root hairs of the non-inoculated second-order lateral roots developing from the taproot harbored polyphenolic
compounds that were stained by TBO. At non-inoculated stage, the average numbers of epidermal cells stained entirely (PC2),
stained partially (PC1) or remaining unstained (PC0) were 16.5 ± 0.7, 0 ± 0, and 0 ± 0, respectively. At the early mantled
stage, the numbers were 6.5 ± 1.6, 5.2 ± 1.4, and 4.2 ± 1.0, and at the mycorrhizal stage, it was 0 ± 0, 0 ± 0, and 32.8 ± 1.3
for PC2, PC1, and PC0, respectively. Total phenolic content in the root tips at each developmental stage declined with ECM
development. The early mantled stage involved a dynamic process of polyphenol localization. However, some epidermal cells
and endodermal cells of the proximal zone accumulated polyphenols. Eventually, polyphenolic compounds, which were found abundantly
in the epidermal cells and root hairs of the non-inoculated lateral roots of the host, disappeared at the mycorrhization process
with the symbiont. 相似文献
14.
Specific PCR primers to identify arbuscular mycorrhizal fungi within colonized roots 总被引:20,自引:0,他引:20
D. Redecker 《Mycorrhiza》2000,10(2):73-80
A set of PCR primers targeted at five major phylogenetic subgroups of arbuscular mycorrhizal fungi (Glomales) was designed
to facilitate specific amplification of internal transcribed spacers and 18 S rRNA gene fragments from colonized roots in
the absence of spores. The subgroups include the recently discovered deeply divergent lineages of Glomales, which could not
be detected by previously reported PCR primers, and the former genus Sclerocystis. Restriction fragment length polymorphism patterns presented allow identification of presently known members of these groups.
The resulting PCR products can be used to identify the fungal symbionts at the genus or species level by restriction digests
or DNA sequencing. A novel DNA extraction method allows visual control of the analyzed roots by staining procedures after
analysis by PCR.
Accepted: 2 April 2000 相似文献
15.
This greenhouse study aimed to examine the contribution of arbuscular mycorrhizal (AM) colonization on the uptake of and tolerance
to nickel (Ni) in sunflower (Helianthus annuus L.). We hypothesized that AM colonization increases Ni content and tolerance in sunflower grown under varying soil Ni concentrations.
The combined effect of AM colonization and soil Ni input on the assimilation of nitrogen, in particular the activity of glutamine
synthetase (GS), in sunflower plants was also investigated. A factorial experimental design was performed with sunflower cv.
Lemon Queen, with or without the AM fungus, Glomus intraradices Schenck & Smith, and treated with 0, 100, 200, or 400 mg Ni kg−1 dry soil (DS). The AM colonization significantly enhanced plant growth and Ni content, especially at the lower soil Ni treatments.
Furthermore, the AM plants exposed to the highest soil Ni level of 400 mg Ni kg−1 DS had a significantly higher shoot Ni extracted percentage than non-AM plants, suggesting that the AM symbiosis contributed
to Ni uptake, then its translocation from roots to shoots. The AM colonization also significantly increased the GS activity
in roots, this being likely an indicator of an enhanced Ni tolerance. These findings support the hypothesis that AM symbiosis
contributes to an enhanced Ni plant uptake and tolerance and should be considered as part of phytoremediation strategies. 相似文献
16.
S. Antony Ceasar S. Lenin Maxwell K. Bhargav Prasad M. Karthigan Savarimuthu Ignacimuthu 《Acta Physiologiae Plantarum》2010,32(3):443-452
A two-stage culture procedure has been developed for highly efficient shoot regeneration from leaf and internode explants
of Bacopa monnieri. Adventitious shoot buds were obtained on the shoot induction medium containing Murashige and Skoog’s (MS) basal salt supplemented
with 1.5 mg/l thidiazuron and 0.5 mg/l naphthalene acetic acid; these shoot buds were subcultured on the multiplication (second)
medium amended with BAP (benzyl amino purine). Multiplication medium containing 0.5 mg/l BAP produced more shoots (135) and
longer shoots (7.8 cm) with more nodes (6). Best response of root induction with more number of roots (16.5) and longer roots
(8.7 cm) was observed in half strength MS basal medium supplemented with 1.0 mg/l IBA (indole-3-butyric acid) and 0.5 mg/l
phloroglucinol. In vitro obtained plants were transferred to the field after hardening with a 100% survival rate. Random amplified
polymorphic DNA analysis was carried out using five random primers. The amplification products were monomorphic in micropropagated
plants and similar to those of mother plant. No polymorphism was detected revealing the genetic integrity of micropropagated
plants. 相似文献
17.
《Mycological Research》2006,110(9):1059-1069
The endangered indigenous tree species Juniperus procera, commonly known as African Pencil Cedar, is an important component of the dry Afromontane vegetation of Ethiopia and was shown to be AM in earlier studies. Here we describe the composition of AM fungi in colonized roots of J. procera from two dry Afromontane forests of Ethiopia. The nuSSU rDNA gene was amplified from colonized roots, cloned and sequenced using AM fungal specific primers that were partly developed for this study. Molecular phylogenetic analysis revealed that all the glomeralean sequences obtained belonged exclusively to the genus Glomus (Glomeraceae). Seven distinct Glomus sequence types were identified that all are new to science. The composition of the AM fungal communities between the sampled trees, and between the two study sites in general, differed significantly. Isolation and utilization of the indigenous AM fungal taxa from the respective sites might be required for successful enrichment plantation of this threatened Juniperus species. 相似文献
18.
Nucleolar oragnizer regions (NORs) of Chinese hamster chromosomes have been demonstrated by using a Coomasie brilliant blue dye (CBB) method. The staining procedure involved is simple and the results are reproducible. The staining process is easily controllable because over-staining of the chromosomes seldom occurs. The CBB solution is stable (pH 3) and can be used for many days at room temperature. Contrary to the silver technique, the stained material in the NORs is resistant to acid extraction. Since it is sensitive to trypsin treatment, it is suggested that the CBB stained material is protein in nature. 相似文献
19.
We investigated the accumulation of reactive oxygen species (ROS) in arbuscular mycorrhizal (AM) roots from Medicago truncatula, Zea mays and Nicotiana tabacum using three independent staining techniques. Colonized root cortical cells and the symbiotic fungal partner were observed to be involved in the production of ROS. Extraradical hyphae and spores from Glomus intraradices accumulated small levels of ROS within their cell wall and produced ROS within the cytoplasm in response to stress. Within AM roots, we observed a certain correlation of arbuscular senescence and H2O2 accumulation after staining by diaminobenzidine (DAB) and a more general accumulation of ROS close to fungal structures when using dihydrorhodamine 123 (DHR 123) for staining. According to electron microscopical analysis of AM roots from Z. mays after staining by CeCl3, intracellular accumulation of H2O2 was observed in the plant cytoplasm close to intact and collapsing fungal structures, whereas intercellular H2O2 was located on the surface of fungal hyphae. These characteristics of ROS accumulation in AM roots suggest similarities to ROS accumulation during the senescence of legume root nodules. 相似文献
20.
Nuclear rDNA instability in in vitro‐generated plants is amplified after sexual reproduction with conspecific wild individuals 下载免费PDF全文
Marcela Rosato Pablo Ferrer‐Gallego Chiara Totta Emilio Laguna Josep A. Rosselló 《Botanical journal of the Linnean Society. Linnean Society of London》2016,181(1):127-137
Using micropropagation through tissue culture has become the most used approach worldwide for mass production for the conservation of endangered species. However, the screening of somaclonal variations generated using in vitro culture is usually restricted to the first generation of micropropagated plants, when they have not yet been released in the field. Accordingly, the fate of genetically modified regenerants after sexual reproduction is usually not assessed and changes in the genetic structures of species are unknown. In this work, we assess the cytogenetic stability of two rDNA gene families in the offspring of experimental crosses between accessions generated after in vitro culture and wild individuals of Cistus heterophyllus (Cistaceae). The cytogenetic rDNA profiles (45S rDNA, 5S rDNA) of 118 accessions including wild and in vitro micropropagated individuals and bi‐directional artificial crosses between wild and in vitro‐generated plants were assessed by fluorescence in situ hybridization (FISH) and Ag‐NOR staining. Plants regenerated by micropropagation showed a lower size of the FISH signals in a 45S rDNA site, but this condition was not present in the wild accessions. Three new cytogenetic and cytological variants were present in 36% of the experimental progeny, involving the amplification of one additional 45S rDNA site and the presence of heteromorphic nucleoli. rDNA‐based genomic instability was present after sexual reproduction between wild and in vitro‐generated plants. The results of this study discourage the use of micropropagated materials for plant conservation unless comprehensive surveys of the genetic integrity and stability of the regenerants are performed after crossing between wild and micropropagated plants. 相似文献