Nitrogen allocation in barley: Relationships between amino acid transport and storage protein synthesis during grain filling

Abstract

Egle, K., Beschow, H. and Merbach, W. 2015. Nitrogen allocation in barley: Relationships between amino acid transport and storage protein synthesis during grain filling. Can. J. Plant Sci. 95: 451Á459. A better knowledge of the source-sink relationships relating to nitrogen allocation within plant and synthesis of storage protein in grains could be of particular importance contributing to better define grain sink capacity for improving nitrogen use efficiency by plant species. The objectives of this study were to assess N partitioning in barley cv 'Barke' prior and after anthesis, and to investigate whether the synthesis of the major storage protein (hordein) is an indicator of the sink strength of the developing grain for nitrogenous compounds. Pot experiments were performed using N fertilizer, labelled N ( 15 N fertilizer) or feeding of labelled proteinogenic and non-proteinogenic amino acids ( N from a-Ala and a-Aib was transferred to grains, but that more (about 37% versus 24%) was retained in the fed leaf when 15 N was applied in the form of a-Aib. The strongest effect was observed in partitioning between N fractions in grains: hordein acted as a main reservoir for 15 N-a-Ala while 15 N-a-Aib predominantly remained in NaCl-extractable fractions (non-protein nitrogen and salt-soluble proteins). The biosynthesis of hordein in grains did not seem to be exclusively the potential sink for nitrogenous compounds but could enhance the transport of amino acids into the grain by the instantaneous incorporation of imported amino acids into hordein.

Seed Storage Proteins of Faba Bean (Vicia faba L): Current Status and Prospects for Genetic Improvement

“…It is hypothesized that the negative correlation between the two traits result when the high demand for N during seed filling stage coincides with decline in soil nutrients in the rhizosphere and nitrogen fixation, resulting in re-mobilization of nitrogen from leaves, which in turn shortens grain filling and reduces seed weights 86 . This is in line with findings by Egle, et al 87 who showed that majority of N accumulated during seed filling in barley was remobilized from leaves and stems, but that ongoing N uptake could also contribute. Furthermore, wheat genotypes with higher capability for post-anthesis N uptake deviate from grain-protein negative relationship [88][89] and selection for this trait has been therefore proposed as a possible criterion for simultaneous improvement of protein content and grain yield.…”

Genetic regulation of growth and nutrient content under phosphorus deficiency in the wild barley introgression library S42IL

“…Carbon and nitrogen contents in roots and shoots were determined from 10 mg of ground samples using a C/N analyser (Vario EL, Elemental Analysis System, Hanau, Germany) at Martin‐Luther‐University following Egle, Beschow, and Merbach ().…”

Inferring vascular architecture of the wheat spikelet based on resource allocation in the branched headt (bht-A1) near isogenic lines

“…TKW is also affected by grain shape and size (Su et al 2018). These characteristics are determined by the temporal and spatial regulation of cell division, cell expansion, and the duration and rate of grain filling (Wheeler et al 1996;Drea et al 2005;Pielot et al 2015;, which are dependent on the availability and acquisition of essential resources (Weber et al 1998;Yang et al 2004;Lopes et al 2006;Egle et al 2015;Weichert et al 2017). We note that grain development in wheat spikelets follows an acropetal order (Kirby 1974;Whingwiri and Stern 1982), showing a decrease in grain weight or dry matter accumulation acropetally within the spikelets (Rawson and Evans 1970;Kirby 1974;Whingwiri et al 1981;.…”