Effect of Vesicular-arbuscular Mycorrhizal Infection on the Distribution of Neutral Phosphatase Activities in Root Cortical Cells

Jeanmaire, Christine; Dexheimer, J.; Marx, Christine E.; Gianinazzi, Silvio; Gianinazzi‐Pearson, Vivienne

doi:10.1016/s0176-1617(85)80095-x

Cited by 35 publications

(20 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar conclusion was drawn for endomycorrhiza by Jeanmaire et al (1985) who showed that a neutral phosphatase activity occurs on the plant membrane around intracellular fungal arbuscules.…”

Section: Discussionsupporting

confidence: 78%

Ultrastructure of cortical root cells of Alnus incana infected by Penicillium nodositatum

et al. 1995

View full text Add to dashboard Cite

SUMMARYPenicillium nodositatum Valla penetrates Alnus incana (L.) Moench roots through deformed root hairs. It then colonizes the cortical cells and induces the formation of myconodules which have structures similar to those of young actinorhizas. The ultrastructure of infected cortical cells has been compared with that of cells infected by pathogenic or symbiotic fungi as well as with that of cells infected by Frankia. Our observations show that an infected host cell shows few visible signs of resistance to the fungal invasion. As soon as P. nodositatum enters the cell, it is surrounded by a wall-like pecto-cellulosic matrix produced by the host cell. The host plasmalemma, invaginated around the endophyte, keeps its integrity as it does in symbiotic associations. At the beginning of the infection, the host cytoplasm and the fungus are intact but when the cell is completely invaded, the host cytoplasm becomes disorganized and subsequently the fungus also senesces, as in roots of Ericaceae infected by an endomycorrhizal fungus or as in older tissues of actinorhizas. P. nodositatum could survive the dead host cell by using its own reserves. Uninfected neighbouring host cells remain intact. P. nodositatum can be considered to behave as a neutral microsymbiont of A. incana, in a way similar to that of a compatible but ineffective Frankia strain.

show abstract

Section: Discussionsupporting

confidence: 78%

Ultrastructure of cortical root cells of Alnus incana infected by Penicillium nodositatum

et al. 1995

View full text Add to dashboard Cite

show abstract

“…However, in cortical parenchyma cells, this wall material progressively thins out around the growing fungus to form a matrix of disorganized fibrils that separates the PAM from the arbuscule wall, creating an interfacial zone of 100 nm or less. The PAM has a neutral phosphatase activity, which is a marker of glycosylation, and some of the interfacial matrix molecules have been identified as typical plant cell wall components (Table 1; Jeanmaire et al, 1985). The variation in interface components between different plants reflects variations in their cell wall makeup.…”

Section: The Symbiotic Interface: From Structure To Functionmentioning

confidence: 99%

Plant Cell Responses to Arbuscular Mycorrhizal Fungi: Getting to the Roots of the Symbiosis

Gianinazzi‐Pearson¹

1996

The Plant Cell

130

View full text Add to dashboard Cite

INTRODUCTIONSince their colonization of terrestrial ecosystems, plants have developed numerous strategies to cope with the diverse biotic and abiotic challenges that are a consequence of their sedentary life cycle. One of the most successful strategies is the ability of root systems to establish mutualistic and reciprocally beneficial symbiotic relationships with microorganisms. Mycorrhizas, the intricate associations roots form with specific fungal groups, are by far the most frequent of these and represent the underground absorbing organs of most plants in nature (Gianinazzi-Pearson, 1984). Through their function in the efficient exploitation of soil mineral resources and their bioprotective role against a number of common soilborne pathogens, mycorrhizas are instrumental in the survival and fitness of many plant taxa in diverse ecosystems, including many crop species (reviewed in Allen, 1991; Bethlenfalvay and Linderman, 1992).Severa1 kinds of mycorrhizal associations can be distinguished according to their morphology and the plant and fungal taxa concerned. They fall almost exclusively into two broad groups: (1) the ectomycorrhizas of woody Angiosperms and Gymnosperms, in which Basidiomycetes, Ascomycetes, or Zygomycetes develop intercellular hyphae from a mycelial sheath covering the surface of short lateral roots; and (2) the endomycorrhizas, characterized by intraradical mycelium growth and intracellular fungal proliferation, which are formed by Basidiomycetes in the Orchidaceae (orchidoid mycorrhiza), Ascomycetes in the Ericales (ericoid mycorrhiza), and Zygomycetes in most other terrestrial plant taxa (arbuscular mycorrhiza; reviewed in Harley and Smith, 1983).Plant compatibility with mycorrhizal fungi is a generalized and ancient phenomenon. Species in >80% of extant plant families are capable of establishing arbuscular mycorrhiza (AM), and fossil evidence suggests that symbioses of this kind existed >400 million years ago in the tissues of the first land plants (Pirozynski and Dalpé, 1989;Remy et al., 1994). As such, the ability of plants to form AM must be under the control of mechanisms that have been conserved in new plant taxa as they appeared during evolution. This compatibility also implies that selective recognition processes in plants discriminate between beneficial and harmful microorganisms and that the essential genetic determinants for AM establishment are common to an extensive part of the plant kingdom.In contrast to their extremely wide host range and despite their ancient origins, only six genera of fungi belonging to the order Glomales of the Zygomycetes have evolved the ability to form AM (Morton and Benny, 1990). lnteractions between an AM fungus and a plant begin when a hypha from a germinating soilborne spore comes into contact with a host root. This step is followed by induction of an appressorium, from which an infection hypha penetrates deep into the parenchyma cortex (Figure lA), where inter-and intracellular proliferation of mycelium is intense. Here, fungal development culm...

show abstract

“…The interface between VA mycorrhizal arbuscules and host cells is generally assumed to be the major site of nutrient transfer between symbionts, and has been examined at the ultrastructure level with similar results for a variety of plant-fungus combinations (Cox & Sanders, 1974;Kinden & Brown, 1975;Holley & Peterson, 1979;Gianinazzi et al, 1983;Jeanmaire et al, 1985). As the fungus penetrates cortical cells, the host wall and plasma membrane invaginate around the penetrating hyphal tip.…”

Section: Cell Wall Precursorsmentioning

confidence: 99%

“…Studies of enzymes by ultracytology show neutral phosphatase activity in the matrix surrounding arbuscules and associated with the host plasma membrane (Gianinazzi et al, 1983;Jeanmaire et al, 1985). The neutral phosphatase activity also occurs along the plasma membrane of non-colonized cortical cells in the root's zones of differentiation and elongation, but not in non-colonized cells that are fully differentiated.…”

Section: Cell Wall Precursorsmentioning

confidence: 99%

Regulation of nutrient transfer between host and fungus in vesicular—arbuscular mycorrhizas

1991

View full text Add to dashboard Cite

summary Although the overwhelming majority of non‐aquatic vascular plants form vesicular‐arbuscular (VA) mycorrhizal associations, the extent of colonization of the host root by any given fungal symbiont varies considerably depending on host and environmental factors. Because VA mycorrhizal fungi are obligate biotrophs, transfer of photosynthate from host to fungus may be an important factor in regulating the extent of VA mycorrhizal formation. Host metabolites must cross the plasma membrane before becoming available to the fungus. Several studies on rates of root exudation under various environmental conditions show a strong correlation between rates of root exudation and percent of root length colonized by VA mycorrhizal fungi. However, passive leakage of simple metabolites from roots as the sole means of regulating fungal colonization seems improbable for an obligate biotroph which has not yet been successfully cultured on any artificial medium. So far there has been insufficient investigation of hormone interactions between symbionts, and of the interference by the fungus in host cell wall synthesis, to evaluate the possible role of these factors in controlling growth of VA mycorrhizal fungi. Cytochemical studies of the host‐fungus interface suggest modification of host plasma membrane ATPase activity as arbuscules develop, but the function of this altered activity remains unresolved. The presence of a linked P1‐photosynthate exchange mechanism on the host plasma membrane analogous to the P1‐photosynthate translocator known to exist in the outer membrane of chloroplasts remains an uninvestigated possible mechanism for balancing photosynthate demand by the fungus with enhanced P uptake.

show abstract

Effect of Vesicular-arbuscular Mycorrhizal Infection on the Distribution of Neutral Phosphatase Activities in Root Cortical Cells

Cited by 35 publications

References 21 publications

Ultrastructure of cortical root cells of Alnus incana infected by Penicillium nodositatum

Ultrastructure of cortical root cells of Alnus incana infected by Penicillium nodositatum

Plant Cell Responses to Arbuscular Mycorrhizal Fungi: Getting to the Roots of the Symbiosis

Regulation of nutrient transfer between host and fungus in vesicular—arbuscular mycorrhizas

Contact Info

Product

Resources

About