title: Hormone- and light-mediated regulation of heat-induced differential petiole growth in Arabidopsis.
abstract: Plants react quickly and profoundly to changes in their environment. A sudden increase in temperature, for example, induces differential petiole growth-driven upward leaf movement (hyponastic growth) in Arabidopsis (Arabidopsis thaliana). We show that accessions that face the strongest fluctuations in diurnal temperature in their natural habitat are least sensitive for heat-induced hyponastic growth. This indicates that heat-induced hyponastic growth is a trait subject to natural selection. The response is induced with kinetics remarkably similar to ethylene- and low light-induced hyponasty in several accessions. Using pharmacological assays, transcript analysis, and mutant analyses, we demonstrate that ethylene and the photoreceptor protein phytochrome B are negative regulators of heat-induced hyponastic growth and that low light, phytochrome A, auxin, polar auxin transport, and abscisic acid are positive regulators of heat-induced hyponastic growth. Furthermore, auxin, auxin polar transport, phytochrome A, phytochrome B, and cryptochromes are required for a fast induction of heat-induced hyponastic growth.
authors.affiliation: Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: van Zanten
authors.forename: Laurentius A C J
authors.initials: LA
authors.lastname: Voesenek
authors.forename: Anton J M
authors.initials: AJ
authors.lastname: Peeters
authors.forename: Frank F
authors.initials: FF
authors.lastname: Millenaar
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D056931:Cryptochromes / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D007210:Indoleacetic Acids / Q000378:metabolism; D008027:Light; D051942:Phytochrome A / Q000378:metabolism; D051939:Phytochrome B / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development*; D018749:RNA, Plant / Q000235:genetics
chemical_list: D056931:Cryptochromes; D007210:Indoleacetic Acids; D051942:Phytochrome A; D010937:Plant Growth Regulators; D018749:RNA, Plant; D051939:Phytochrome B; D000040:Abscisic Acid