Untersuchungen zur Wirkungsweise der Aminosäure- konjugate der Auxine in wachsenden Geweben.

Three different amino acid conjugates of the auxin naphthalene-1-acetic acid (NAA)-naphthalene-1-acetyl-L-aspartic acid, naphthalene-1-acetyl-D-aspartic acid, and naphthalene- 1-acetyl-L-glutamic acid - have been prepared and tested for growth stimulation in tobacco callus tissues, sunflower hypocotyls, and wheat coleoptiles. All conjugates show less auxin activities than NAA. The ratios of concentrations for more or less the same growth stimulation are 1:25 to 1:100 and less. Each test tissue grows the least on the D-aspartic acid conjugate. These results lead to the conclusion that growth stimulation by these conjugates has to be an indirect one, probably due to their hydrolysis generating free auxins. It is unknown whether the hydrolysis takes place inside or outside the cells. [ABSTRACT FROM AUTHOR]