title: Allelic differences in Medicago truncatula NIP/LATD mutants correlate with their encoded proteins' transport activities in planta.
abstract: Medicago truncatula NIP/LATD gene, required for symbiotic nitrogen fixing nodule and root architecture development, encodes a member of the NRT1(PTR) family that demonstrates high-affinity nitrate transport in Xenopus laevis oocytes. Of three Mtnip/latd mutant proteins, one retains high-affinity nitrate transport in oocytes, while the other two are nitrate-transport defective. To further examine the mutant proteins' transport properties, the missense Mtnip/latd alleles were expressed in Arabidopsis thaliana chl1-5, resistant to the herbicide chlorate because of a deletion spanning the nitrate transporter AtNRT1.1(CHL1) gene. Mtnip-3 expression restored chlorate sensitivity in the Atchl1-5 mutant, similar to wild type MtNIP/LATD, while Mtnip-1 expression did not. The high-affinity nitrate transporter AtNRT2.1 gene was expressed in Mtnip-1 mutant roots; it did not complement, which could be caused by several factors. Together, these findings support the hypothesis that MtNIP/LATD may have another biochemical activity.
authors.affiliation: Department of Biological Sciences; University of North Texas; Denton, TX USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Salehin
authors.affiliation: Department of Biological Sciences; University of North Texas; Denton, TX USA.
authors.forename: Ying-Sheng
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Department of Biological Sciences; University of North Texas; Denton, TX USA.
authors.forename: Rammyani
authors.initials: R
authors.lastname: Bagchi
authors.affiliation: Department of Plant and Soil Science; Delaware Biotechnology Institute; Newark, DE USA.
authors.forename: D Janine
authors.initials: DJ
authors.lastname: Sherrier
authors.affiliation: Department of Biological Sciences; University of North Texas; Denton, TX USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dickstein
mesh_terms: D000483:Alleles; D001692:Biological Transport / Q000235:genetics / Q000502:physiology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D010940:Plant Proteins