Urea retranslocation from senescing Arabidopsis leaves is promoted by DUR3-mediated urea retrieval from leaf apoplast.

ABSTRACT: In plants, urea derives either from root uptake or protein degradation. Although large quantities of urea are released during senescence, urea is mainly seen as a short-lived nitrogen (N) catabolite serving urease-mediated hydrolysis to ammonium. Here, we investigated the roles of DUR3 and of urea in N remobilization. During natural leaf senescence urea concentrations and DUR3 transcript levels showed a parallel increase with senescence markers like ORE1 in a plant age- and leaf age-dependent manner. Deletion of DUR3 decreased urea accumulation in leaves, whereas the fraction of urea lost to the leaf apoplast was enhanced. Under natural and N deficiency-induced senescence DUR3 promoter activity was highest in the vasculature, but was also found in surrounding bundle sheath and mesophyll ce

SUBMITTER: Bohner A 

PROVIDER: S-EPMC4329417 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature