title: PhEXPA1, a Petunia hybrida expansin, is involved in cell wall metabolism and in plant architecture specification.
abstract: Expansins are wall-loosening proteins that induce wall stress relaxation and irreversible wall extension in a pH-dependent manner. Despite a substantial body of work has been performed on the characterization of many expansins genes in different plant species, the knowledge about their precise biological roles during plant development remains scarce. To yield insights into the expansion process in Petunia hybrida, PhEXPA1, an expansin gene preferentially expressed in petal limb, has been characterized. The constitutive overexpression of PhEXPA1 significantly increased expansin activity, cells size and organ dimensions. Moreover, 35S::PhEXPA1 transgenic plants exhibited an altered cell wall polymer composition and a precocious timing of axillary meristem development compared with wild-type plants. These findings supported a previous hypothesis that expansins are not merely structural proteins involved in plant cell wall metabolism but they also take part in many plant development processes. Here, to support this expansins dual role, we discuss about differential cell wall-related genes expressed in PhEXPA1 expression mutants and gradients of altered petunia branching pattern.
authors: Department of Biotechnology, University of Verona, Verona, Italy.
authors: Silvia
authors: S
authors: Dal Santo
authors: Marianna
authors: M
authors: Fasoli
authors: Erika
authors: E
authors: Cavallini
authors: Giovanni Battista
authors: GB
authors: Tornielli
authors: Mario
authors: M
authors: Pezzotti
authors: Sara
authors: S
authors: Zenoni
mesh_terms: D048429:Cell Size; D002473:Cell Wall / Q000378:metabolism*; D035264:Flowers / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000254:growth & development*; D009154:Mutation; D032306:Petunia / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism
chemical_list: D010940:Plant Proteins