Inhibition of carotenoid accumulation and abscisic acid biosynthesis in fluridone-treated dark-grown barley.
Treatment of dark-grown barley with 0.1 mM fluridone inhibited carotenoid accumulation but did not alter plastid biogenesis. Plastids isolated from dark-grown control and dark-grown fluridone-treated plants were similar in size and protein compositions. Dehydration of dark-grown control barley caused abscisic acid levels to increase 30-40-fold in 4 h, while plants treated with 0.1 mM fluridone accumulated very little abscisic acid in response to dehydration. These results suggest that fluridone-treated plants do not accumulate abscisic acid because of carotenoid deficiency rather than plastid dysfunction. Dark-grown barley plants treated with 0.31 microM fluridone accumulated low levels of carotenoids. Dehydration of these plants resulted in a 4-8-fold increase in abscisic acid and a decrease in antheraxanthin, violaxanthin and neoxanthin, but no change in beta-carotene or lutein plus zeaxanthin levels. This result is consistent with the suggestion that xanthophylls are precursors to abscisic acid in dehydrated plants.
D000040:Abscisic Acid / Q000096:biosynthesis*; D000220:Adaptation, Biological; D002338:Carotenoids / Q000172:deficiency / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003509:Cyclohexanecarboxylic Acids / Q000096:biosynthesis*; D003624:Darkness; D003890:Desiccation; D002523:Edible Grain / Q000378:metabolism*; D006540:Herbicides / Q000494:pharmacology; D001467:Hordeum / Q000254:growth & development / Q000378:metabolism*; D010455:Peptides / Q000032:analysis; D011728:Pyridones / Q000494:pharmacology*
D003509:Cyclohexanecarboxylic Acids; D006540:Herbicides; D010455:Peptides; D011728:Pyridones; D002338:Carotenoids; C013351:fluridone; D000040:Abscisic Acid