Relationship between sink-induced N remobilisation and seed filling in barley

High yield and grain quality can only be achieved at optimum supply of the seed with carbon and nitrogen assimilates. In barley, the ear-near photosynthesising organs, flag leaf and glumes, are important for supplying the grain. During seed filling C and N compounds are remobilised from these organs and transported to filling grains. Understanding these processes can potentially contribute to crops with higher N-use efficiency. This project addresses the interactions between sink-induced N remobilisation and grain filling in barley. We plan correlation and network analysis between transcript and metabolite profiles in order to identify associations between gene expression and metabolite concentrations at corresponding stages in flag leaves, glumes and grains. We intend to identify regulators (gene products, metabolites), which control remobilisation, grain filling and its interactions. Amino acid transporters with a potential role establishing source (flag leaf, glume) and/or sink activity (grain) for N remobilisation/grain filling will be functionally characterised and validated by RNAi approaches. We plan comprehensive analysis of available transgenic barley models to find out whether increased grain-sink strength can have positive impact on N remobilisation efficiency. Metabolite/hormone analysis of the grain vascular bundle will be performed after micro-dissection during early to mid grain filling. We intend to analyse dynamics of metabolites along development with the aim to identify those with a potential role in signaling N demand of the grain to the source.

Molecular GeneticsIPK
IPK Gatersleben, Germany

Dr. Hans Weber
Dr. Winfriede Weschke
Stefan Kohl

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