Ethylene regulates root growth through effects on auxin biosynthesis and transport dependent auxin distribution Journal Article


Author(s): Růžička, Kamil; Ljung, Karin; Vanneste, Steffen; Podhorská, Radka; Beeckman, Tom; Friml, Jiří; Benková, Eva
Article Title: Ethylene regulates root growth through effects on auxin biosynthesis and transport dependent auxin distribution
Affiliation
Abstract: In plants, each developmental process integrates a network of signaling events that are regulated by different phytohormones, and interactions among hormonal pathways are essential to modulate their effect. Continuous growth of roots results from the postembryonic activity of cells within the root meristem that is controlled by the coordinated action of several phytohormones, including auxin and ethylene. Although their interaction has been studied intensively, the molecular and cellular mechanisms underlying this interplay are unknown. We show that the effect of ethylene on root growth is largely mediated by the regulation of the auxin biosynthesis and transport-dependent local auxin distribution. Ethylene stimulates auxin biosynthesis and basipetal auxin transport toward the elongation zone, where it activates a local auxin response leading to inhibition of cell elongation. Consistently, in mutants affected in auxin perception or basipetal auxin transport, ethylene cannot activate the auxin response nor regulate the root growth. In addition, ethylene modulates the transcription of several components of the auxin transport machinery. Thus, ethylene achieves a local activation of the auxin signaling pathway and regulates root growth by both stimulating the auxin biosynthesis and by modulating the auxin transport machinery.
Keywords: Models, Biological; Mutation; Biological Transport; plant roots; Genes, Reporter; Indoleacetic Acids; Ethylenes; Meristem
Journal Title: Plant Cell
Volume: 19
Issue 7
ISSN: 1040-4651
Publisher: American Society of Plant Biologists  
Date Published: 2007-07-01
Start Page: 2197
End Page: 2212
DOI: 10.1105/tpc.107.052126
Open access: no