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Proton (H + ) flux signature for the presymbiotic development of the arbuscular mycorrhizal fungi
Author(s) -
Ramos Alessandro C.,
Façanha Arnoldo R.,
Feijó José A.
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2007.02344.x
Subject(s) - hypha , symbiosis , biology , botany , fungus , flux (metallurgy) , mycorrhiza , chemistry , bacteria , genetics , organic chemistry
Summary• Ion dynamics are important for cell nutrition and growth in fungi and plants. Here, the focus is on the relationship between the hyphal H + fluxes and the control of presymbiotic growth and host recognition by arbuscular mycorrhizal (AM) fungi. • Fluxes of H + around azygopores and along lateral hyphae of Gigaspora margarita during presymbiotic growth, and their regulation by phosphate (P) and sucrose (Suc), were analyzed with an H + ‐specific vibrating probe. Changes in hyphal H + fluxes were followed after induction by root exudates (RE) or by the presence Trifolium repens roots. • Differential sensitivity to P‐type ATPase inhibitors (orthovanadate or erythrosin B) suggests an asymmetric distribution or activation of H + ‐pump isoforms along the hyphae of the AM fungi. Concentration of P and Suc affected the hyphal H + fluxes and growth rate. However, further increases in H+ efflux and growth rate were observed when the fungus was growing close to clover roots or pretreated with RE. • The H + flux data correlate with those from polarized hyphal growth analyses, suggesting that spatial and temporal alterations of the hyphal H + fluxes are regulated by nutrient availability and might underlie a pH signaling elicitation by host RE during the early events of the AM symbiosis.