Wegmüller, Sarah Svistoonoff, Sergio Reinhardt, Didier Stuurman, Jeroen Amrhein, Nikolaus Bucher, Marcel 2008-05-08 The active endogenous dTph1 system of the Petunia hybrida mutator line W138 has been used in several forward-genetic mutant screens that were based on visible phenotypes such as flower morphology and color. In contrast, defective symbiotic phosphate (P_i) transport in mycorrhizal roots of Petunia is a hidden molecular phenotype as the symbiosis between plant roots and fungi takes place below ground, and, while fungal colonization can be visualized histochemically, P_i transport and the activity of P_i transporter proteins cannot be assessed visually. Here, we report on a molecular approach in which expression of a mycorrhiza-inducible bi-functional reporter transgene and insertional mutagenesis in Petunia are combined. Bi-directionalization of a mycorrhizal P_i transporter promoter controlling the expression of two reporter genes encoding firefly luciferase and GUS allows visualization of mycorrhiza-specific P_i transporter expression. A population of selectable transposon insertion mutants was established by crossing the transgenic reporter line with the mutator W138, from which the P_itransporter downregulated (ptd1) mutant was identified, which exhibits strongly reduced expression of mycorrhiza-inducible P_i transporters in mycorrhizal roots. application/pdf https://folia.unifr.ch/global/documents/300918 https://folia.unifr.ch/documents/300918/files/reinhardt_tdi.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1365-313X.2008.03474.x info:eu-repo/semantics/openAccess License undefined The Plant Journal. - 2008, vol. 54, no. 6, p. 1115 - 1127 Petunia forward genetics transposon mutagenesis mycorrhiza phosphate transporter luciferase info:eu-repo/classification/udc/57 A transgenic dTph1 insertional mutagenesis system for forward genetics in mycorrhizal phosphate transport of Petunia http://purl.org/coar/resource_type/c_6501