Mycorrhiza Research
Dr. Ingrid Kottke

Hyphae of mycorrhizal fungus, stained by methyl blue, in the cortical cells of an epiphytic orchid root
New structures and morphotyping of arbuscular mycorrhiza of trees Hartig Net Institute of Special Botany and Mycology

Mycorrhizas of temperate forests

Structure of the Hartig net and establishment of ectomycorrhizas

Studying a variety of field collected mycorrhizas, we clarified for the first time the general three dimensional structure of ectomycorrhizas (Fig. 1) [5].

Fig. 1: Block diagram displaying the Hartig net and the hyphal sheath of ectomycorrhizas [first published in 5].
Fig. 2: Early state of mycorrhiza development in Petri dish cultures (Laccaria amethystina – Picea abies). Photo: I. Kottke.

Using in vitro ECM-cultures (Fig. 2) [10] and TEM-investigations we described the transfer-cell-like ultra structure of the Hartig net (Fig. 3, 4) [11, 6, 19].

Fig. 3: TEM mircograph and scheme of the Hartig net of ectomycorrhizas [Amanita muscaria-Picea abies] displaying active hyphae arranged in a transfer cell- like structure [first published in 11].

We showed that early events in mycorrhiza formation are attachment of hyphae to the suberized root surface followed by splitting off the suberin layer and induction of typical finger like-branching of hyphae (Fig. 4) [60,37].

Fig. 4: TEM micrograph displaying hyphae attaching the root surface and dissolving the superficial suberin layer of the root. Image: I. Kottke.

Previously, we found that contact of hyphae to the root surface induced reduction of soluble and cell wall bound phenolics facilitating ingression of hyphae between the root cell walls (Fig. 5) [15].

Fig. 5: Cell wall bound, fungi-toxic ferulic acid is lowered in mycorrhizal roots [HPLC analysis; first pubished in 15].

Next research project: 
Description of ectomycorrhiza morphotypes

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e-book: "Mykorrhiza – Pilz-Wurzel-Symbiosen" (2016, WikiBooks)
6th Oct 2016

© 2008 - 2016 Dr. rer. nat. habil Ingrid Kottke apl. Prof. i. R.
University of Tübingen | Germany | E-Mail

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