Work

Increased nitrogen use efficiency via amino acid remobilization from source to sink organs in Brassica napus

Year: 2022

Type: article

Abstract: Nitrogen (N) is an essential plant growth nutrient whose coordinated distribution from source to sink organs is crucial for seed development and overall crop yield. We compared high and low N use efficiency (NUE) Brassica napus (rapeseed) genotypes. Metabonomics and transcriptomics revealed that leaf senescence induced by N deficiency promoted amino acid allocation from older to younger leaves in the high-NUE genotype at the vegetative growth stage. Efficient source to sink remobilization of amino acids elevated the numbers of branches and pods per plant under a N-deficiency treatment during the reproductive stage. A 15N tracer experiment confirmed that more amino acids were partitioned into seeds from the silique wall during the pod stage in the high-NUE genotype, owing mainly to variation in genes involved in organic N transport and metabolism. We suggest that the greater amino acid source-to-sink allocation efficiency during various growth stages in the high-NUE genotype resulted in higher yield and NUE under N deficiency. These findings support the hypothesis that strong amino acid remobilization in rapeseed leads to high yield, NUE, and harvest index.

Source: The Crop Journal

DOI: 10.1016/j.cj.2022.05.011