Structural Requirements of Abscisic Acid (ABA) and its Impact on Water Flow During Radial Transport of ABA Analogues Through Maize Roots.
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.
Sauter
Angela
A
Julius von Sachs Institut der Universität Würzburg, Lehrstuhl Botanik I, Julius von Sachs Platz 2, D 97082 Würzburg, Germany.
Abrams
Suzanne R.
SR
Hartung
Wolfram
W