English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Summary  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  DUR 3 and of urea in N remobilization. During natural leaf senescence urea concentrations and   DUR 3  transcript levels showed a parallel increase with senescence markers like   ORE 1  in a plant age‐ and leaf age‐dependent manner. Deletion of   DUR 3  decreased urea accumulation in leaves, whereas the fraction of urea lost to the leaf apoplast was enhanced. Under natural and N deficiency‐induced senescence   DUR 3  promoter activity was highest in the vasculature, but was also found in surrounding bundle sheath and mesophyll cells. An analysis of petiole exudates from wild‐type leaves revealed that N from urea accounted for >13% of amino acid N. Urea export from senescent leaves further increased in  ureG‐2  deletion mutants lacking urease activity. In the  dur3 ureG  double insertion line the absence of  DUR 3 reduced urea export from leaf petioles. These results indicate that urea can serve as an early metabolic marker for leaf senescence, and that  DUR 3‐mediated urea retrieval contributes to the retranslocation of N from urea during leaf senescence.

Urea retranslocation from senescing Arabidopsis leaves is promoted by DUR 3‐mediated urea retrieval from leaf apoplast