Nitrogen deficiency and senescence in Arabidopsis and oilseed rape: Transcriptome response and the role of nitrate transporters

• Applicant: Professor Dr. Reinhard Kunze
• Subject Area: Plant Physiology
• Term: from 2009 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 46691270

Among the major field crops oilseed rape has a particularly low nitrogen use efficiency (NUE). For improving the NUE of oilseed rape it is important to advance the understanding of N-remobilization and -allocation mechanisms, to select genotypes with high NUE and to sensitively diagnose the N status of the plants. We work on two topics towards this goal:1) We aim to identify gene expression biomarkers that indicate early stages of N deficiency and senescence before phenotypic symptoms are visible. By transcriptome analysis of N deficiency-stressed plants we have identified hundreds of biomarker candidates in the first funding period. The reliability and robustness of the candidates for N deficiency and senescence initiation prognosis is currently validated and shall be challenged in various oilseed rape cultivars grown under different conditions.2) The results of the first funding period suggest that in Arabidopsis the nitrate transporters NRT1.5 and NRT1.7 are involved in signaling the N status between leaves and roots and in executing the plants' responses to N deficiency, including senescence initiation and an altered lipid/protein ratio in seeds. By overexpressing these NRT proteins in Arabidopsis and oilseed rape we want to investigate whether NUE can be improved.

• DFG Programme: Research Units
• Subproject of: FOR 948: Nitrogen Uptake, Metabolism and Remobilisation in Leaves during Plant Senescence
• Participating Person: Dr. Christine Rausch