title: Structural Requirements of Abscisic Acid (ABA) and its Impact on Water Flow During Radial Transport of ABA Analogues Through Maize Roots.
abstract: The effect of (+) (ABA) and (?)-abscisic acid and nine ABA metabolites, precursors or derivatives on radial water movement through maize roots, was investigated using a suction technique (Freundl and others 1998). (+)-ABA, (+)- and (?)-abscisyl aldehyde, (+)-8?-hydroxymethyl ABA, (+)-8?-methylene, and (+)-8?-acetylene ABA stimulated radial water transport. (?)-ABA, phaseic acid, and (+)-8?-acetylene methyl ABA were ineffective. ELISA analysis for ABA detected and apparent increase of free ABAxyl in xylem sap of excised root systems that were perfused with either (+)-abscisyl aldehyde, (+)-8?-methylene, (+)8?-acetylene-ABA, or ABA-glucose ester. The analogues (+)-8?-hydroxymethyl ABA and (?)-abscisyl aldehyde passed the cortex of maize roots without changing the ABAxyl. The data from this study permit conclusions about the structural requirements for hormonal regulation of hydraulic conductivity.
authors.affiliation: Julius von Sachs Institut der Universität Würzburg, Lehrstuhl Botanik I, Julius von Sachs Platz 2, D 97082 Würzburg, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Sauter
authors.forename: Suzanne R.
authors.initials: SR
authors.lastname: Abrams
authors.forename: Wolfram
authors.initials: W
authors.lastname: Hartung