Dataset Information

Relative qPCR to quantify colonization of plant roots by arbuscular mycorrhizal fungi.

ABSTRACT: Arbuscular mycorrhiza fungi (AMF) are beneficial soil fungi that can promote the growth of their host plants. Accurate quantification of AMF in plant roots is important because the level of colonization is often indicative of the activity of these fungi. Root colonization is traditionally measured with microscopy methods which visualize fungal structures inside roots. Microscopy methods are labor-intensive, and results depend on the observer. In this study, we present a relative qPCR method to quantify AMF in which we normalized the AMF qPCR signal relative to a plant gene. First, we validated the primer pair AMG1F and AM1 in silico, and we show that these primers cover most AMF species present in plant roots without amplifying host DNA. Next, we compared the relative qPCR method with traditional microscopy based on a greenhouse experiment with Petunia plants that ranged from very high to very low levels of AMF root colonization. Finally, by sequencing the qPCR amplicons with MiSeq, we experimentally confirmed that the primer pair excludes plant DNA while amplifying mostly AMF. Most importantly, our relative qPCR approach was capable of discriminating quantitative differences in AMF root colonization and it strongly correlated (Spearman Rho = 0.875) with quantifications by traditional microscopy. Finally, we provide a balanced discussion about the strengths and weaknesses of microscopy and qPCR methods. In conclusion, the tested approach of relative qPCR presents a reliable alternative method to quantify AMF root colonization that is less operator-dependent than traditional microscopy and offers scalability to high-throughput analyses.

SUBMITTER: Bodenhausen N

PROVIDER: S-EPMC7910240 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Relative qPCR to quantify colonization of plant roots by arbuscular mycorrhizal fungi.

Bodenhausen Natacha N Deslandes-Hérold Gabriel G Waelchli Jan J Held Alain A van der Heijden Marcel G A MGA Schlaeppi Klaus K

Mycorrhiza 20210121 2

Arbuscular mycorrhiza fungi (AMF) are beneficial soil fungi that can promote the growth of their host plants. Accurate quantification of AMF in plant roots is important because the level of colonization is often indicative of the activity of these fungi. Root colonization is traditionally measured with microscopy methods which visualize fungal structures inside roots. Microscopy methods are labor-intensive, and results depend on the observer. In this study, we present a relative qPCR method to q ...[more]

PMID: 33475800

Similar Datasets

Project description:Background and aimsArbuscular mycorrhizal fungi (AMF) play an important role in plant nutrition and protection against pests and diseases, as well as in soil structuration, nutrient cycling and, generally speaking, in sustainable agriculture, particularly under drought, salinity and low input or organic agriculture. However, little is known about the genetics of the AMF-plant association in tomato. The aim of this study was the genetic analysis of root AMF colonization in tomato via the detection of the quantitative trait loci (QTLs) involved.MethodsA population of 130 recombinant inbred lines derived from the wild species Solanum pimpinellifolium, genotyped for 1899 segregating, non-redundant single nucleotide polymorphisms (SNPs) from the SolCAP tomato panel, was characterized for intensity, frequency and arbuscular abundance of AMF colonization to detect the QTLs involved and to analyse the genes within their peaks (2-2.6 Mbp).Key resultsThe three AMF colonization parameters were highly correlated (0.78-0.97) and the best one, with the highest heritability (0.23), corresponded to colonization intensity. A total of eight QTLs in chromosomes 1, 3, 4, 5, 6, 8, 9 and 10 were detected. Seven of them simultaneously affected intensity and arbuscule abundance. The allele increasing the expression of the trait usually came from the wild parent in accordance with the parental means, and several epistatic interactions were found relevant for breeding purposes. SlCCaMK and SlLYK13 were found among the candidate genes. Carbohydrate transmembrane transporter activity, lipid metabolism and transport, metabolic processes related to nitrogen and phosphate-containing compounds, regulation of carbohydrates, and other biological processes involved in the plant defence were found to be over-represented within the QTL peaks.ConclusionsIntensity is genetically the best morphological measure of tomato root AMF colonization. Wild alleles can improve AMF colonization, and the gene contents of AMF colonization QTLs might be important for explaining the establishment and functioning of the AMF-plant symbiosis.

Project description:Arbuscular mycorrhizal fungi (AMF) can establish symbiotic associations with the roots of most terrestrial plants, thereby improving the tolerance of the host plants to biotic and abiotic stresses. Although AMF cannot synthesize lipids de novo, they can obtain lipids from the root cells for their growth and development. A recent study reveals that AMF can directly take up myristate (C14:0 lipid) from the environment and produce a large amount of hyphae in asymbiotic status; however, the effect of environmental lipids on AM symbiosis is still unclear. In this study, we inoculated tomato (Solanum lycopersicum) with AMF in an in vitro dual culture system and a sand culture system, and then applied exogenous myristate to the substrate, in order to explore the effect of exogenous lipids on the mycorrhizal colonization of AMF. We investigated the hyphae growth, development, and colonization of AMF, and examined the gene expression involved in phosphate transport, lipid biosynthesis, and transport. Results indicate that exogenous lipids significantly stimulated the growth and branching of hyphae, and significantly increased the number of hyphopodia and mycorrhizal colonization of AMF, with arbuscular abundance and intraradical spores or vesicles being the most promoted. In contrast, exogenous myristate decreased the growth range and host tropism of the germ tubes, and largely inhibited the exchange of nutrition between symbionts. As a result, exogenous myristate did not affect the plant growth. This study suggests that lipids promote mycorrhizal colonization by enhancing the growth and development of AMF hyphae and increasing their contact opportunities with plant roots. To the best of our knowledge, this is the first report that shows that lipids promote the colonization of AMF. Our study highlights the importance of better understanding the roles of environmental lipids in the establishment and maintenance of AM symbiosis and, thus, in agricultural production.

Dataset Information

Relative qPCR to quantify colonization of plant roots by arbuscular mycorrhizal fungi.

Publications

Relative qPCR to quantify colonization of plant roots by arbuscular mycorrhizal fungi.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets