Naphthenic acids inhibit root water transport, gas exchange and leaf growth in aspen (Populus tremuloides) seedlings.
Effects of sodium naphthenates (NAs) on root hydraulic conductivity (Lp) and gas exchange processes were examined in aspen (Populus tremuloides Michx.) seedlings grown in solution culture. Exposure of roots to NAs for 3-5 weeks significantly decreased Lp and stomatal conductance. Root-absorbed NAs also decreased leaf chlorophyll concentration, net photosynthesis and leaf growth. Short-term (< or = 2 h) exposure of excised roots to NAs significantly decreased root water flow (Qv) with a concomitant decline in root respiration. We conclude that NAs metabolically inhibited Lp, likely by affecting water channel activity, and that this inhibition could be responsible for the observed reductions in gas exchange and leaf growth.
Kamaluddin
M
M
Department of Renewable Resources, 4-42 Earth Sciences Bldg., University of Alberta, Edmonton, AB T6G 2E3, Canada.
Zwiazek
Janusz J
JJ
D002264:Carboxylic Acids / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects* / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects*; D018526:Plant Transpiration / Q000187:drug effects; D032107:Populus / Q000187:drug effects* / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development; D014197:Trees / Q000187:drug effects* / Q000254:growth & development; D014867:Water / Q000378:metabolism
D002264:Carboxylic Acids; D014867:Water; C046170:naphthenic acid