title: Variable expansin expression in Arabidopsis leads to different growth responses.
abstract: Expansins have long been implicated in the control of cell wall extensibility. However, despite ample evidence supporting a role for these proteins in the endogenous mechanism of plant growth, there are also examples in the literature where the outcome of altered expansin gene expression is difficult to reconcile with a simplistic causal linkage to growth promotion. To investigate this problem, we report on the analysis of transgenic Arabidopsis plants in which a heterologous cucumber expansin can be inducibly overexpressed. Our results indicate that the effects of expansin expression on growth depend on the degree of induction of expansin expression and the developmental pattern of organ growth. They support the role of expansin in directional cell expansion. They are also consistent with the idea that excess expansin might itself impede normal activities of cell wall modifications, culminating in both growth promotion and repression depending on the degree of expression.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom; Institute of Systems Biology, Universiti Kebangsaan Malaysia, UKM Bangi 43600, Selangor Darul Ehsan, Malaysia.
authors.forename: Hoe-Han
authors.initials: HH
authors.lastname: Goh
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sloan
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom; Laboratory of Plant Molecular Biology, Polish Academy of Sciences Botanical Garden - Centre for Biodiversity Protection in Powsin, ul Prawdziwka 2, Warsaw 02-973, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Malinowski
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom. Electronic address: a.fleming@sheffield.ac.uk.
authors.forename: Andrew
authors.initials: A
authors.lastname: Fleming
mesh_terms: D017360:Arabidopsis / Q000378:metabolism* / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D018546:Hypocotyl / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D010940:Plant Proteins
keywords: Arabidopsis; Expansin; Hypocotyl; Leaf development; Petiole