From embryogenesis to fruit set, auxin governs many important aspects of plant growth and development. Through its ability to promote cell division and determine the direction of growth, auxin participates in tropic responses and dictates the layout of the plant. The spatial distribution of auxin within plants is key to its activity. Auxin transporters function coordinately to direct the cell-t...

From embryogenesis to fruit set, auxin governs many important aspects of plant growth and development. Through its ability to promote cell division and determine the direction of growth, auxin participates in tropic responses and dictates the layout of the plant. The spatial distribution of auxin within plants is key to its activity. Auxin transporters function coordinately to direct the cell-t...

We have found that chromosaponin I (CSI), a gamma-pyronyl-triterpenoid saponin isolated from pea (Pisum sativum L. cv Alaska), specifically interacts with AUX1 protein in regulating the gravitropic response of Arabidopsis roots. Application of 60 microM CSI disrupts the vertically oriented elongation of wild-type roots grown on agar plates but orients the elongation of agravitropic mutant aux1-...

Arabidopsis root architecture is regulated by shoot-derived signals such as nitrate and auxin. We report that mutations in the putative auxin influx carrier AUX1 modify root architecture as a result of the disruption in hormone transport between indole-3-acetic acid (IAA) source and sink tissues. Gas chromatography-selected reaction monitoring-mass spectrometry measurements revealed that the au...

Coordination of cell and tissue polarity commonly involves directional signaling. In the Arabidopsis root epidermis, cell polarity is revealed by basal, root tip-oriented, hair outgrowth from hair-forming cells (trichoblasts). The plant hormone auxin displays polar movements and accumulates at maximum concentration in the root tip. The application of polar auxin transport inhibitors evokes chan...

In plants, auxin is a key regulator of development and is unique among plant hormones in that its function requires polarized transport between neighboring cells to form concentration gradients across various plant tissues. Although putative auxin-influx and -efflux transporters have been identified by using molecular genetic approaches, a detailed functional understanding for many of these tra...

From embryogenesis to fruit set, auxin governs many important aspects of plant growth and development. Through its ability to promote cell division and determine the direction of growth, auxin participates in tropic responses and dictates the layout of the plant. The spatial distribution of auxin within plants is key to its activity. Auxin transporters function coordinately to direct the cell-t...

From embryogenesis to fruit set, auxin governs many important aspects of plant growth and development. Through its ability to promote cell division and determine the direction of growth, auxin participates in tropic responses and dictates the layout of the plant. The spatial distribution of auxin within plants is key to its activity. Auxin transporters function coordinately to direct the cell-t...

The plant hormones auxin and ethylene have been shown to play important roles during root hair development. However, cross talk between auxin and ethylene makes it difficult to understand the independent role of either hormone. To dissect their respective roles, we examined the effects of two compounds, chromosaponin I (CSI) and 1-naphthoxyacetic acid (1-NOA), on the root hair developmental pro...

Plants employ a specialized transport system composed of separate influx and efflux carriers to mobilize the plant hormone auxin between its site(s) of synthesis and action. Mutations within the permease-like AUX1 protein significantly reduce the rate of carrier-mediated auxin uptake within Arabidopsis roots, conferring an agravitropic phenotype. We are able to bypass the defect within auxin up...