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TRANSPORT OF SUGAR IN PHYTOPHTHORA PALMIVORA (BUTL.) BUTL.
Author(s) -
SHEARD J.,
FARRAR J. F.
Publication year - 1987
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.1469-8137.1987.tb00863.x
Subject(s) - sucrose , fructose , hexose , sugar , invertase , chemistry , hydrolysis , phytophthora palmivora , biochemistry , kinetics , biology , botany , phytophthora , enzyme , physics , quantum mechanics
S ummary The kinetics of uptake of sucrose, glucose and fructose by Phytophthora palmivora are all biphasic. At low concentrations, glucose and fructose share a common, high‐affinity, hexose carrier, and sucrose is probably hydrolyzed extracellularly at these concentrations before the transport of the resultant hexoses by this carrier. At higher concentrations, a low‐affinity carrier may transport sucrose directly, but this carrier appears to have a higher affinity for glucose than sucrose. Activity of neutral invertase (β‐D‐fructofuranoside fructohydrolase) in both soluble and particulate (cell‐wall) preparations is considerably in excess of the highest rates of sucrose uptake.