DPX 1840-induced Organogenesis in Xanthi-nc Tobacco Plants.

The synthetic growth regulant DPX 1840 (3,3a-dihydro-2-(p-methoxyphenyl)-8H-pyrazolo[5, 1-a]isoindol-8-one) induced callus growth and subsequent tissue differentiation on cut surfaces of decapitated Xanthi-nc tobacco plants (Nicotiana tabacum). Callus formation and organogenesis induced by DPX 1840 depended on the presence of leaves. The adventitious meristems developed into either vegetative or flowering shoots. Pedicels that bore single flower buds developed two abscission zones that caused the buds to abscise before anthesis. The various morphological and physiological processes affected by DPX 1840 suggests that this growth regulator affects the endogenous hormonal distribution and/or activity.