caa a22 4500 397521685 CHVBK 20180308164634.0 cr unu---uuuuu 161202e199504 xx s 000 0 eng 10.1093/jxb/46.4.423 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.4.423 Regulation of IBA synthetase from maize (Zea mays L.) by drought stress and ABA [Elektronische Daten] [Jutta Ludwig-Müller, Birgit Schubert, Kerstin Pieper] The rate of indole-3-butyric acid (IBA) synthesis in maize seedlings is dependent on the culture conditions of the plants. When the seedlings were grown on filter paper soaked with different amounts of water, the activity of IBA synthetase differed strongly. High amounts of water (150 and 200 ml per bowl) inhibited IBA synthesis completely in vitro, whereas 30 and 50 ml water per bowl increased the activity dramatically. Under conditions where IBA synthetase was inhibited (150 ml H2O), an increase of enzyme activity was observed when abscisic acid (ABA) was exogenously added in concentrations between 5×10−4 to 5×10−7 M. Under ‘drought' conditions (50 ml H2O per bowl) the same ABA concentrations were inhibitory. Jasmonic acid and salicylic acid also enhanced IBA synthetase activity to some extent, whereas indole-3-acetic acid (IAA) and kinetin had no effect. Activity could also be enhanced by osmotic stress (NaCI and sorbitol), but not under temperature stress. In accompanying investigations the endogenous contents of IAA, IBA, and ABA under the different culture conditions have been determined as well as the energy charge of the seedlings. Similar observations have been made with Amaranthus, wheat and pea seedlings © Oxford University Press Articles nationallicence Abscisic acid nationallicence Amaranthus paniculatus nationallicence drought stress nationallicence inole-3-butyric acid biosynthesis nationallicence Pisum sativum nationallicence Triticum aestivum nationallicence Zea mays nationallicence Ludwig-Müller Jutta Botanisches Institut, J.W. Goethe-Universität, Siesmayerstrasse 70, Postfach 111932, D-60054 Frankfurt am Main, Germany aut Schubert Birgit Botanisches Institut, J.W. Goethe-Universität, Siesmayerstrasse 70, Postfach 111932, D-60054 Frankfurt am Main, Germany aut Pieper Kerstin Botanisches Institut, J.W. Goethe-Universität, Siesmayerstrasse 70, Postfach 111932, D-60054 Frankfurt am Main, Germany aut Journal of Experimental Botany Oxford University Press 46/4(1995-04), 423-432 0022-0957 46:4<423 1995 46 exbotj https://doi.org/10.1093/jxb/46.4.423 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.4.423 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ludwig-Müller Jutta Botanisches Institut, J.W. Goethe-Universität, Siesmayerstrasse 70, Postfach 111932, D-60054 Frankfurt am Main, Germany aut NATIONALLICENCE 700 1- Schubert Birgit Botanisches Institut, J.W. Goethe-Universität, Siesmayerstrasse 70, Postfach 111932, D-60054 Frankfurt am Main, Germany aut NATIONALLICENCE 700 1- Pieper Kerstin Botanisches Institut, J.W. Goethe-Universität, Siesmayerstrasse 70, Postfach 111932, D-60054 Frankfurt am Main, Germany aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/4(1995-04), 423-432 0022-0957 46:4<423 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford