TRIFLURALIN UPTAKE AND ITS EFFECT ON ABA CONTENT IN GROWING MAIZE ANDPEA ROOTS

Some characteristics of the herbicide trifluralin (TF), applied to roo ts of Zea mays and Pisum sativum, are studied: its uptake and effects on growth and free ABA content. Maize roots are sensitive to TF (5 mu M) since their elongation is slowed down and their diameter strongly i ncreased whereas pea roots are not affected by TF at this concentratio n. C-14-TF uptake was higher in maize than in pea roots, but only in t he elongation zone. ABA level - which was found to be involved in TF a ction (Locher and Pilet, 1994) - is about 10 times higher in pea than in maize roots. Moreover, applied TF induced an increase of ABA conten t in maize roots. TF sensitivity and tolerance for maize and pea roots are discussed in relation to TF uptake and endogenous ABA.