Cytoskeletal Drugs and Gravity‐Induced Lateral Auxin Transport in Rice Coleoptiles

Abstract

Abstract: Gravity‐induced events such as amyloplast sedimentation and lateral auxin transport were probed with cytoskeletal drugs in coleoptiles of rice ( Oryza sativa L.). Amyloplast sedimentation was retarded by taxol. Lateral transport of auxin ( 3 H‐indoleacetic acid) was strongly inhibited by EPC (ethyl N‐phenylcarbamate), but only partially inhibited by taxol. 1 mM EPC reduced gravitropism while phototropism was not affected. The findings suggest that microtubules may transduce pressure or proximity of amyloplasts to the auxin exporter in the plasmalemma.