Foliar modifications induced by inhibition of polar transport of auxin

Abstract

The effects of auxin polar transport inhibitors,9-hydroxyfluorene-9-carboxylic acid (HFCA); 2, 3, 5-triiodobenzoic acid (TIBA) and trans-cinnamic acid (CA) on leaf pattern formation were investigated with shoots formed from cultured leaf explants of tobacco and cultured pedicel explants of Orychophragmus violaceus, and the seedlings of tobacco and Brassica chinensis. Although the effective concentration varies with the inhibitors used, all of the inhibitors induced the formation of trumpet-shaped and/or fused leaves. The frequency of trumpet-shaped leaf formation was related to the concentration of inhibitors in the medium. Histological observation of tobacco seedlings showed that there was only one main vascular bundle and several minor vascular bundles in normal leaves of the control, but there were several vascular bundles of more or less the same size in the trumpet-shaped leaves of treated ones. These results indicated that auxin polar transport played an important role on bilateral symmetry of leaf growth.

Auxin depletion from leaf primordia contributes to organ patterning

“…To further understand whether auxin efflux contributes to leaf polarity, we examined leaf patterning in auxin efflux mutants. Consistent with previous reports that treatment by auxin polar transport inhibitors induces lateral organ adaxial-abaxial polarity defects in several dicot species (38,39), we found the formation of trumpet-like and rod-like leaves with polarity defects in Arabidopsis pin1 mutants (Fig. 5A, Fig.…”

“…5, Fig. S14, and Table S1), in plants treated with auxin transport inhibitors (39), and in MPΔ plants (Fig. 2, Fig.…”

Synthesis and plant growth inhibitory activity of N-trans-cinnamoyltyramine: its possible inhibition mechanisms and biosynthesis pathway

“…Auxin is a potent hormone that impacts root hair development (Bibikova & Gilroy 2003), and aberrations in auxin availability or signaling can cause defects in root hair growth and morphology (Liu et al 1993;Ni et al 1999). Compound cinnamic acid is also proposed to inhibit polar auxin transport by blocking the transport at the efflux carrier (Ni et al 1999).…”

“…Compound cinnamic acid is also proposed to inhibit polar auxin transport by blocking the transport at the efflux carrier (Ni et al 1999). In turn, reduced availability of auxin decreases root hair growth.…”

Meristem control of leaf patterning

“…In fact, a study carried out in the late 1990s by the Xu ZhuHong lab at the Shanghai Institute of Plant Physiology, Chinese Academy of Sciences has implied that auxin transport may be involved in leaf polarity patterning [6], although detailed mechanism remains unclear. During the very early stage of the establishment of the leaf primordium, auxin was transported into cells that initiate the primordium.…”