Ethylene-Induced Differential Growth of Petioles in Arabidopsis. Analyzing Natural Variation, Response Kinetics, and Regulation

• Published in: Plant physiology (Bethesda) Vol. 137; no. 3; pp. 998 - 1008
• Main Authors: Millenaar, Frank F, Cox, Marjolein C.H, Jong van Berkel, Yvonne E.M. de, Welschen, Rob A.M, Pierik, Ronald, Voesenek, Laurentius A.J.C, Peeters, Anton J.M
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.03.2005; American Society of Plant Physiologists
• Subjects: Amino Acid Oxidoreductases - metabolism; Arabidopsis - growth & development; Arabidopsis thaliana; Biological and medical sciences; Cell physiology; ethylene; Ethylene production; Ethylenes - metabolism; Fundamental and applied biological sciences. Psychology; Hot Temperature; hyponastic growth; Kinetics; Leaf blade; Leaves; Light; light intensity; Molecular and cellular biology; molecular sequence data; nucleotide sequences; Petioles; Plant cells; Plant growth; Plant growth regulators; Plant Growth Regulators - physiology; Plant Leaves - growth & development; plant response; Plants; Signal Transduction; Time Factors; Whole Plant and Ecophysiology; Arabidopsis thaliana; Signal transduction; Gene; Cruciferae; Growth; Dicotyledones; Angiospermae; Ethylene; Spermatophyta; Kinetics; Petiole
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.104.053967

Plants can reorient their organs in response to changes in environmental conditions. In some species, ethylene can induce resource-directed growth by stimulating a more vertical orientation of the petioles (hyponasty) and enhanced elongation. In this study on Arabidopsis (Arabidopsis thaliana), we show significant natural variation in ethylene-induced petiole elongation and hyponastic growth. This hyponastic growth was rapidly induced and also reversible because the petioles returned to normal after ethylene withdrawal. To unravel the mechanisms behind the natural variation, two contrasting accessions in ethylene-induced hyponasty were studied in detail. Columbia-0 showed a strong hyponastic response to ethylene, whereas this response was almost absent in Landsberg erecta (Ler). To test whether Ler is capable of showing hyponastic growth at all, several signals were applied. From all the signals applied, only spectrally neutral shade (20 [micro]mol m⁻² s⁻¹) could induce a strong hyponastic response in Ler. Therefore, Ler has the capacity for hyponastic growth. Furthermore, the lack of ethylene-induced hyponastic growth in Ler is not the result of already-saturating ethylene production rates or insensitivity to ethylene, as an ethylene-responsive gene was up-regulated upon ethylene treatment in the petioles. Therefore, we conclude that Ler is missing an essential component between the primary ethylene signal transduction chain and a downstream part of the hyponastic growth signal transduction pathway.