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Polyphosphate dynamics in mycorrhizal roots during colonization of an arbuscular mycorrhizal fungus
Author(s) -
Ohtomo Ryo,
Saito Masanori
Publication year - 2005
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.1469-8137.2005.01425.x
Subject(s) - polyphosphate , colonization , hypha , spore , fungus , mycorrhiza , glomus , inoculation , biology , phosphate , botany , phycomycetes , horticulture , symbiosis , bacteria , biochemistry , microbiology and biotechnology , genetics
Summary• Inorganic polyphosphate (poly P) has been considered to be a translocatable form of phosphate (P i ) in arbuscular mycorrhizal fungi (AMF). Here we examined time‐course changes in poly P content during the AMF colonization process. • Onion ( Allium cepa ) plants were cultured with or without inoculation with Gigaspora margarita for 2–8 wk with periodic sampling. Poly P in the extracts, purified through gel filtration, was quantified by the reverse reaction of polyphosphate kinase. • The length of poly P in mycorrhizal roots appeared to be shorter than in extraradical hyphae or in spores of the AMF, indicating that AMF depolymerize poly P before providing P i to the host. The poly P content increased as colonization proceeded, and was highly correlated with the weight of the colonized roots. • These results support the model that AMF supply P i to the host through the poly P pool, and that the poly P content of a mycorrhizal root can be a good indicator of the P i ‐supplying activity of AMF.