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Fluoride inhibits root water transport and affects leaf expansion and gas exchange in aspen ( Populus tremuloides ) seedlings
Author(s) -
Kamaluddin Mohammed,
Zwiazek Janusz J.
Publication year - 2003
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2003.00040.x
Subject(s) - chemistry , sodium fluoride , respiration , stomatal conductance , photosynthesis , fluoride , hydraulic conductivity , horticulture , botany , transpiration , biology , soil water , inorganic chemistry , biochemistry , ecology
The effects of sodium fluoride (0.3, 5 and 10 m M NaF) on root hydraulic conductivity, and gas exchange processes were examined in aspen ( Populus tremuloides Michx.) seedlings grown in solution culture. A long‐term exposure of roots to NaF significantly decreased root hydraulic conductivity ( L p ) and stomatal conductance ( g s ). Root absorbed NaF significantly affected electrolyte leakage in leaf tissues and substantially restricted leaf expansion. NaF did not significantly affect leaf chlorophyll contents but decreased net photosynthesis ( P n ). A short‐term exposure of excised roots to 5 m M NaF and KF significantly decreased root water flow ( Q v ) with a concomitant decline in root respiration and reduced g s when applied through intact roots or excised stems. The same molar concentration of NaCl also decreased Q v and g s in intact seedlings, but to a lesser extent than NaF or KF, and did not significantly affect root respiration. The results suggest that fluoride metabolically inhibited Q v or L p , probably by affecting water channel activity. We suggest that the metabolic inhibition of L p by root‐absorbed fluoride affected gas exchange and leaf expansion in aspen seedlings.