title: Altered expression of the PTR/NRT1 homologue OsPTR9 affects nitrogen utilization efficiency, growth and grain yield in rice.
abstract: The plant PTR/NRT1 (peptide transporter/nitrate transporter 1) gene family comprises di/tripeptide and low-affinity nitrate transporters; some members also recognize other substrates such as carboxylates, phytohormones (auxin and abscisic acid), or defence compounds (glucosinolates). Little is known about the members of this gene family in rice (Oryza sativa L.). Here, we report the influence of altered OsPTR9 expression on nitrogen utilization efficiency, growth, and grain yield. OsPTR9 expression is regulated by exogenous nitrogen and by the day-night cycle. Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake, promotion of lateral root formation and increased grain yield. On the other hand, down-regulation of OsPTR9 in a T-DNA insertion line (osptr9) and in OsPTR9-RNAi rice plants had the opposite effect. These results suggest that OsPTR9 might hold potential for improving nitrogen utilization efficiency and grain yield in rice breeding.
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Fang
authors.forename: Kuaifei
authors.initials: K
authors.lastname: Xia
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Marianne Suter
authors.initials: MS
authors.lastname: Grotemeyer
authors.forename: Stefan
authors.initials: S
authors.lastname: Meier
authors.forename: Doris
authors.initials: D
authors.lastname: Rentsch
authors.forename: Xinlan
authors.initials: X
authors.lastname: Xu
authors.forename: Mingyong
authors.initials: M
authors.lastname: Zhang
mesh_terms: D009584:Nitrogen / Q000378:metabolism*; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D009584:Nitrogen