barcelonatraveller.info: Hidden Partners: Mycorrhizal Fungi and Plants
Associations between plants and the fungal root microbiota. Different types A Functional Plant–Fungal Association in a Nonmycorrhizal Plant. The important connection between roots and fungi. Underground Plants are a lot like people–they need relationships to thrive. At first glance. In natural forests, hundreds of fungal species colonize plant roots. The preference or specificity for partners in these symbiotic relationships is a.
Mycorrhizal fungi encompass many major groups of the fungus Kingdom and in the past were divided into two non-evolutionarily related groups: Ectomycorrhizal fungi ensheath the root cells but usually do not penetrate them extracellular.
Endomycorrhizal fungi penetrate and enter the cells of a plant root intracellular.
WHAT ARE MYCORRHIZAE?
Modern research has lead to the recognition of seven types of mycorrhizal fungi, subdividing the old, traditional groups. The new nomenclature is often more precise and specific to the associated plant taxa. The relatively homogenous ectomycorrhizal group largely remains with only the addition of the subgroup ectendomycorrhizas.
The endomycorrhizal group has been dismantled, but specific types are now recognized: Vescicular-Arbuscular Mycorrhizas, the Orchid mycorrihzas, and those which associate with the Ericaceae Blueberry family: Fungi are heterotropic organisms, and must absorb their food.
Fungi also have the ability to easily absorb elements such a phosphorus and nitrogen which are essential for life. Plants are autotropic, producing their food in the form of carbohydrates through the process of photosynthesis. However, plants often have difficulty obtaining and absorbing many of the essential nutrients needed for life, specifically nitrogen and phosphorus.
In addition, because of the sampling design, the root samples were considered to approximately represent the belowground biomass composition of the plant community at the study site.Mycorrhizal Fungi Animation
DNA extraction, PCR, and pyrosequencing One terminal root was randomly selected from each of the sampling positions. We sequenced host plant chloroplast rbcL and fungal ITS sequences based on a tag-encoded massively parallel pyrosequencing analysis Toju et al.
The first and second PCR steps for the ITS region were conducted using the same buffer systems and temperature profiles as those of rbcL. To obtain more than ITS reads per sample on average, the first and the second samples were sequenced separately using a GS Junior sequencer Roche, Basel, Switzerland.
The sequencing of the first samples was conducted according to the manufacturer's instructions.
Mycorrhizal Fungi and Plant Roots | MOTHER EARTH NEWS
The amplicons of the remaining samples were pooled and purified, and then sequenced in the second run.
Assembling of pyrosequencing reads Hereafter, the bioinformatics pipeline is described, referring to the criteria for the standardized description of next-generation sequencing methods Nilsson et al. After the trimming step, 84, 15, rbcL and 69, ITS reads and 84, 16, rbcL and 67, ITS reads reads for the first and second runs, respectively, passed the filtering process in which rbcL and ITS reads with shorter than bp excluding forward primer and molecular ID positions were discarded.
RbcL and ITS reads were recognized by the primer position sequences and analyzed separately. For each gene, pyrosequencing reads were sorted based on combinations of the sample-specific molecular IDs and pyrosequencing runs i. Molecular ID and forward primer sequences were removed before the assembly process.
Denoising of sequencing data was performed based on the assembly analysis detailed below cf. For the analysis of the host plant rbcL gene, reads were assembled using Assams-assembler v0.
These consensus sequences among-sample consensus sequences were compared to the reference rbcL sequences in the NCBI nucleotide database http: Of theITS reads, reads were discarded as chimeras, leaving a total ofreads. The within-sample consensus sequences represented by thereads were assembled across samples. Of thereads, were excluded as singletons.
Samples with fewer than 20 high-quality reads were eliminated, leaving root samples. Based on the molecular identification, OTUs were classified into ectomycorrhizal fungi, arbuscular mycorrhizal fungi, and fungi with unknown nutritional modes Data S3.
B: Mycorrhizae: The Symbiotic Relationship between Fungi and Roots - Biology LibreTexts
To screen for ectomycorrhizal fungi, we referred to a review by Tedersoo et al. Data S2 ; cf. From this process, a binary matrix depicting the presence or absence of OTUs in each sample was obtained Data S4: In the matrix, the plant species information of each root sample was supplied based on the rbcL data see above. In the matrix, rows represented plant species and columns represented fungal OTUs. In addition, for each plant species, the number of fungal OTUs unique to the plant or the number of fungal OTUs shared with other plant species was indicated.
31.3B: Mycorrhizae: The Symbiotic Relationship between Fungi and Roots
Thus, we conducted a further analysis of plant—fungal associations to screen for fungi preferentially associated with specific host plant species and those with a broad host range by statistically investigating how each fungal OTU was shared among the dominant plant species. For each pair of the five most common host species Fig. S1 Awe used the multinomial species classification method i.
- Mycorrhizal Fungi and Plant Roots: A Symbiotic Relationship
Results Pyrosequencing and community data matrices In total, we found fungal OTUs excluding singletons and possible chimeras from the sequenced terminal root samples Data S2. The mean number of OTUs observed in a sample was 8. The total number of observed OTUs increased almost linearly with increasing sample size Fig. Of the OTUs observed, Of these OTUs, At the order level, Among them, Agaricales