RRC ID 3124
Author Zhao Z, Ma JF, Sato K, Takeda K.
Title Differential Al resistance and citrate secretion in barley (Hordeum vulgare L.).
Journal Planta
Abstract While barley ( Hordeum vulgare L.) is the most sensitive species to Al toxicity among small-grain crops, variation in Al resistance between cultivars does exist. We examined the mechanism responsible for differential Al resistance in 21 barley varieties. Citrate was secreted from the roots in response to Al stress. A positive correlation between citrate secretion and Al resistance [(root elongation with Al)/(root elongation without Al)] and a negative correlation between citrate secretion and Al content of root apices, were obtained, suggesting that citrate secretion from the root apices plays an important role in excluding Al and thereby detoxifying Al. The Al-induced secretion of citrate was characterized using an Al-resistant variety (Sigurdkorn) and an Al-sensitive variety (Kearney). In Sigurdkorn, Al-induced secretion of citrate occurred within 20 min, and the secretion did not increase with increasing external Al concentration. The Al-induced citrate secretion ceased at low temperature (6 degrees C) and was inhibited by anion-channel inhibitors. Internal citrate content of root apices was increased by Al exposure in Sigurdkorn, but was not affected in Kearney. The activity of citrate synthase was unaffected by Al in both Al-resistant and Al-sensitive varieties. The secretion rate of organic acid anions from barley was the lowest among wheat, rye and triticale.
Volume 217(5)
Pages 794-800
Published 2003-9-1
DOI 10.1007/s00425-003-1043-2
PMID 12734756
MeSH Adaptation, Physiological / drug effects Adaptation, Physiological / physiology* Aluminum / metabolism Aluminum / toxicity* Anions / metabolism Citrate (si)-Synthase / drug effects Citrate (si)-Synthase / metabolism Citric Acid / metabolism* Hordeum / drug effects Hordeum / growth & development Hordeum / metabolism* Plant Roots / drug effects Plant Roots / growth & development Plant Roots / metabolism Poaceae / drug effects Poaceae / growth & development Poaceae / metabolism
IF 3.39
Times Cited 92
Barley Akashinriki (J520) Hinode Hadaka (J097) Sazanshu