Project Details
Projekt
Forms of retranslocated nitrogen during leaf senescence and nitrogen deficiency
Applicant
Professor Dr. Nicolaus von Wirén
Subject Area
Plant Cultivation, Plant Nutrition, Agricultural Technology
Term
from 2009 to 2015
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 46691270
Nitrogen (N) retranslocation from senescing leaves to the grains is one of the limiting factors for an efficient utilization of fertilizer N. Our previous studies showed that urea-N can account for >13% of retranslocated amino acid-N and that the urea transporter DUR3 can increase N retranslocation by retrieval of apoplastic urea upstream of phloem loading. The present Project 5 Forms of retranslocated nitrogen 3 project aims at investigating further the contribution of different N forms and their sense-cence-regulated transporters to N retrieval in senescing leaves and to N retranslocation. In barley, the retranslocation efficiency of 15N-labeled urea and other N forms will be assessed in wild-type and transgenic plants with altered expression of membrane transporters or transcription factors. A regulatory link of these N transporters to upstream transcription factors and to salicylic acid as a putative leaf-inherent signal will be investigated in the model species Arabidopsis. To determine the relevance of leaf-inherent signals for N retranslocation in rapeseed, physiological and molecular analyses will be performed in hydroponics and in the field. Emphasis will be placed on rapeseed hybrid lines that have an outstanding N efficiency under field conditions.Keywords: phloem loading, nitrogen retranslocation, AMT, DUR3, nitrogen starvation, nitrogen efficiency.
DFG Programme
Research Units
