Testing the effect of biological control agents on the formation of vesicular arbuscular mycorrhiza

Wyss, Peter; Böller, Th.; Wiemken, Andres

doi:10.1007/bf00009382

Cited by 40 publications

(23 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An induced accumulation of large amounts of glyceollin in soybean roots infected by R. solani has been reported (20). An induced accumulation of large amounts of glyceollin in soybean roots infected by R. solani has been reported (20).…”

Section: Resultsmentioning

confidence: 98%

Response of Soybean Pathogens to Glyceollin

Lygin¹,

Hill²,

Zernova³

et al. 2010

Phytopathology®

View full text Add to dashboard Cite

Plants recognize invading pathogens and respond biochemically to prevent invasion or inhibit colonization in plant cells. Enhancing this response in crop plants could improve sustainable methods to manage plant diseases. To enhance disease resistance in soybean, the soybean phytoalexin glyceollin was assessed in soybean hairy roots of two soybean genotypes, Spencer and PI 567374, transformed with either soybean isoflavone synthase (IFS2) or chalcone synthase (CHS6) genes that were inoculated with the soybean pathogens Diaporthe phaseolorum var. meridionales, Macrophomina phaseolina, Sclerotinia sclerotiorum, and Phytophthora sojae. The hairy-root-transformed lines had several-fold decreased levels of isoflavone daidzein, the precursor of glyceollin, and considerably lower concentrations of glyceollin induced by pathogens measured 5 days after fungal inoculation compared with the nontransformed controls without phenolic transgenes. M. phaseolina, P. sojae, and S. sclerotiorum grew much more on IFS2- and CHS6-transformed roots than on control roots, although there was no significant difference in growth of D. phaseolorum var. meridionales on the transformed hairy-root lines. In addition, glyceollin concentration was lower in D. phaseolorum var. meridionales-inoculated transformed and control roots than roots inoculated with the other pathogens. Glyceollin inhibited the growth of D. phaseolorum var. meridionales, M. phaseolina, P. sojae, S. sclerotiorum, and three additional soybean pathogens: Cercospora sojina, Phialophora gregata, and Rhizoctonia solani. The most common product of glyceollin conversion or degradation by the pathogens, with the exception of P. sojae, which had no glyceollin degradation products found in the culture medium, was 7-hydroxyglyceollin.

show abstract

Section: Resultsmentioning

confidence: 98%

Response of Soybean Pathogens to Glyceollin

Lygin¹,

Hill²,

Zernova³

et al. 2010

Phytopathology®

View full text Add to dashboard Cite

show abstract

“…In some cases streptomycetes inhibit fungal growth. Streptomyces griseoviridis for example, has been shown to depress mycorrhiza formation (Wyss et al, 1992). Other streptomycetes have a stimulatory effect on fungi, such as Streptomyces orientalis, which stimulates spore germination of some AMF (Tylka et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

Characterisation of microbial communities colonising the hyphal surfaces of arbuscular mycorrhizal fungi

et al. 2010

View full text Add to dashboard Cite

Arbuscular mycorrhizal fungi (AMF) are symbiotic soil fungi that are intimately associated with the roots of the majority of land plants. They colonise the interior of the roots and the hyphae extend into the soil. It is well known that bacterial colonisation of the rhizosphere can be crucial for many pathogenic as well as symbiotic plant-microbe interactions. However, although bacteria colonising the extraradical AMF hyphae (the hyphosphere) might be equally important for AMF symbiosis, little is known regarding which bacterial species would colonise AMF hyphae. In this study, we investigated which bacterial communities might be associated with AMF hyphae. As bacterialhyphal attachment is extremely difficult to study in situ, we designed a system to grow AMF hyphae of Glomus intraradices and Glomus proliferum and studied which bacteria separated from an agricultural soil specifically attach to the hyphae. Characterisation of attached and non-attached bacterial communities was performed using terminal restriction fragment length polymorphism and clone library sequencing of 16S ribosomal RNA (rRNA) gene fragments. For all experiments, the composition of hyphal attached bacterial communities was different from the non-attached communities, and was also different from bacterial communities that had attached to glass wool (a non-living substratum). Analysis of amplified 16S rRNA genes indicated that in particular bacteria from the family of Oxalobacteraceae were highly abundant on AMF hyphae, suggesting that they may have developed specific interactions with the fungi.

show abstract

“…B. cereus strain VA1 could be actively involved in the degradation of the fungal hyphae or could form a commensal relationship with the hyphae and benefit from released carbon. Reductions in spore germination and hyphal length at the extramatrical stage have also been observed as effects of soil microorganisms (40,60), suggesting that bacterial associations can sometimes be antagonistic.…”

Section: Discussionmentioning

confidence: 99%

Use of Bromodeoxyuridine Immunocapture To Identify Active Bacteria Associated with Arbuscular Mycorrhizal Hyphae

Artursson

Jansson

2003

Appl Environ Microbiol

117

View full text Add to dashboard Cite

Arbuscular mycorrhizae are beneficial for crops grown under low-till management systems. Increasingly, it is becoming apparent that bacteria associated with mycorrhizae can enhance the beneficial relationship between mycorrhizae and plants. However, it has been difficult to study these relationships by conventional techniques. In this study actively growing bacteria were identified in soil from an undisturbed fallow field known to contain arbuscular mycorrhizae by using molecular tools to eliminate the need for cultivation. A thymidine analog, bromodeoxyuridine (BrdU), was added to the soil and incubated for 2 days. DNA was extracted, and the newly synthesized DNA was isolated by immunocapture of the BrdU-containing DNA. The active bacteria in the community were identified by 16S rRNA gene PCR amplification and DNA sequence analysis. Based on 16S rRNA gene sequence information, a selective medium was chosen to isolate the corresponding active bacteria. Bacillus cereus strain VA1, one of the bacteria identified by the BrdU method, was isolated from the soil and tagged with green fluorescent protein. By using confocal microscopy, this bacterium was shown to clearly attach to arbuscular mycorrhizal hyphae. This study was the first to use this combination of molecular and traditional approaches to isolate, identify, and visualize a specific bacterium that is active in fallow soil and associates with arbuscular mycorrhizal hyphae.

show abstract

Testing the effect of biological control agents on the formation of vesicular arbuscular mycorrhiza

Cited by 40 publications

References 5 publications

Response of Soybean Pathogens to Glyceollin

Response of Soybean Pathogens to Glyceollin

Characterisation of microbial communities colonising the hyphal surfaces of arbuscular mycorrhizal fungi

Use of Bromodeoxyuridine Immunocapture To Identify Active Bacteria Associated with Arbuscular Mycorrhizal Hyphae

Contact Info

Product

Resources

About