Actin versus tubulin configuration in arbuscule-containing cells from mycorrhizal tobacco roots

• Published in: The New phytologist Vol. 140; no. 4; pp. 745 - 752
• Main Authors: GENRE, A., BONFANTE, P.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.12.1998; Blackwell
• Subjects: actin; Actins; Agronomy. Soil science and plant productions; Arbuscular mycorrhizas; Biological and medical sciences; Cell membranes; Cell walls; Cytoskeleton; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Fungi; Gigaspora margarita; Mesophyll cells; Microfilaments; Microtubules; Nicotiana tabacum L; Parasitism and symbiosis; perifungal membrane; Plant cells; Plant physiology and development; Plants; Symbiosis; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); tubulin; tubulin; Gigaspora margarita; Nicotiana tabacum L; actin; Arbuscular mycorrhizas; perifungal membrane; Symbiosis; Symbionte; Root; Phycomycetes; Stimulant plant; Nicotiana tabacum; Fungi; Endomycorrhiza; Tubulin; Actin; Ultrastructure; Dicotyledones; Angiospermae; Mycorrhiza; Cytoskeleton; Spermatophyta; Solanaceae; Comparative study; Thallophyta
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1046/j.1469-8137.1998.00314.x

The involvement of the cytoskeleton in symbiotic interactions such as arbuscular mycorrhizas has received little attention. In this paper, we examine the organization of actin in tobacco mycorrhizal roots and compare actin and tubulin patterns within arbuscule-containing cells. Our results show drastic reorganization of microfilaments and microtubules upon fungal infection and how those new cytoskeletal patterns relate to the host cytoplasm rearrangement and the intracellular fungal structures. Whereas in uninfected cells a network of cortical and perinuclear actin filaments was observed, in infected cells actin filaments closely follow the fungal branches and envelop the whole arbuscule in a dense coating network. Microtubules are less closely connected with the fungus surface. They run across the whole arbuscule mass, linking branches to each other and to the host cell cortex and nucleus. These major differences between the two cytoskeletal components are used to advance some suggestions concerning their contribution to structural functions in the plant–fungus interactions during the mycorrhizal symbiosis.