title: Engineering the root-soil interface via targeted expression of a synthetic phytase gene in trichoblasts.
abstract: For biochemical modification of the root-soil interface, the engineered secretion of stable enzymes from trichoblasts (= root hair bearing rhizodermal cells) is proposed. As a reporter activity, we chose to express a synthetic gene encoding a secretory phytase (PHY) directed by a trichoblast-specific promoter in root hair cells of the crop plant potato. Transgenic plants produced and secreted phytase in sufficient amounts to release phosphate from phytate in liquid medium. When grown in an unsterile substrate containing phytate, transgenic plants accumulated 40% more P in leaves than wild-type plants. The improved P nutrition driven by trichoblast-targeted expression and subsequent secretion of PHY illustrates the potential of using trichoblast-targeted expression of suitable enzymes for future applications in plant nutrition, phytoremediation and molecular farming.
authors.affiliation: Swiss Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon, 8315 Lindau, Switzerland.
authors.forename: Philip
authors.initials: P
authors.lastname: Zimmermann
authors.forename: Gerardo
authors.initials: G
authors.lastname: Zardi
authors.forename: Martin
authors.initials: M
authors.lastname: Lehmann
authors.forename: Christophe
authors.initials: C
authors.lastname: Zeder
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Amrhein
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Frossard
authors.forename: Marcel
authors.initials: M
authors.lastname: Bucher