AtNPF5.5, a nitrate transporter affecting nitrogen accumulation in Arabidopsis embryo

Sophie Léran (1) , Bharti Garg , Yann Boursiac (1) , Claire Corratgé-Faillie (1) , Chantal Brachet (1) , Pascal Tillard (1) , Alain Gojon (1) , Benoît Lacombe (1)

1 BPMP - Biochimie et Physiologie Moléculaire des Plantes

Dipeptide (Leu-Leu) and nitrate transport activities of 26 Arabidopsis NPF (NRT1/PTR Family) proteins were screened in Saccharomyces cerevisiae and Xenopus laevis oocytes, respectively. Dipeptide transport activity has been confirmed for 2 already known dipeptide transporters (AtNPF8.1 and AtNPF8.3) but none of the other tested NPFs displays dipeptide transport. The nitrate transport screen resulted in the identification of two new nitrate transporters, AtNPF5.5 and AtNPF5.10. The localization of the mRNA coding for NPF5.5 demonstrates that it is the first NPF transporter reported to be expressed in Arabidopsis embryo. Two independent homozygous npf5.5 KO lines display reduced total nitrogen content in the embryo as compared to WT plants, demonstrating an effect of NPF5.5 function on the embryo nitrogen content. Finally, NPF5.5 gene produces two different transcripts (AtNPF5.5a and AtNPF5.5b) encoding proteins with different N-terminal ends. Both proteins are able to transport nitrate in xenopus oocytes.

Mots clés: NPF5.5; AtNPF5.5a and AtNPF5.5b; transport nitrate; Xenopus laevis oocytes; transporter AtNPF8.1 and AtNPF8.3; Arabidopsis; Saccharomyces cerevisiae; Dipeptide (Leu-Leu); nitrate

Domaines: Sciences du Vivant [q-bio]; Biologie végétale

Sophie Léran, Bharti Garg, Yann Boursiac, Claire Corratgé-Faillie, Chantal Brachet, et al.. AtNPF5.5, a nitrate transporter affecting nitrogen accumulation in Arabidopsis embryo. Scientific Reports, 2014, 5, pp.7962. ⟨10.1038/srep07962⟩. ⟨hal-01141003⟩