Effects of genotype, season, and nitrogen nutrition on gene expression and protein accumulation in wheat grain.

G A Chope,S P Penson,D G Bhandari,S J Powers,Y Wan,P R Shewry,M J Hawkesford

doi:10.1021/jf500625c

G A Chope, S P Penson + Show 5 more

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https://doi.org/10.1021/jf500625c

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Abstract

Six commercial U.K. cultivars of winter wheat selected to represent different abilities to partition nitrogen into grain protein were grown in replicated field trials at five different sites over three seasons. The proportion of LMW glutenin subunits decreased and the proportion of gliadins increased during grain development and in response to N application. Differences were observed between the proportions of LMW glutenin subunits and gliadins in low- and high-protein grain, these two fractions being decreased and increased, respectively. There was little effect of grain protein content on the proportions of either the HMW glutenin subunits or large glutenin polymers, which are enriched in these subunits, with the latter increasing during development in all cultivars. The proportion of total protein present in polymers in the mature grain decreased with increasing N level. Correlations were also observed between the abundances of gliadin protein transcripts and the corresponding proteins.

Highlights

The relationship between fertilizer inputs and harvest outputs is of vital importance for all crops, in the context of increasing pressure to reduce nitrogen usage
Whereas an inverse correlation is generally observed between the yield and grain protein content of bread wheat,[2] some cultivars consistently accumulate higher protein contents than would be expected based on their yields
These have been defined as exhibiting grain protein deviation[3] and may provide a basis for the future development of wheat cultivars that require less nitrogen fertilization to achieve acceptable protein contents for breadmaking

Summary

Introduction

The relationship between fertilizer inputs and harvest outputs is of vital importance for all crops, in the context of increasing pressure to reduce nitrogen usage. Several studies have identified differences in the nitrogen use efficiency of modern and older cultivars, including high-quality breadmaking cultivars such as Xi19, Hereward, and Malacca.[1] whereas an inverse correlation is generally observed between the yield and grain protein content of bread wheat,[2] some cultivars consistently accumulate higher protein contents than would be expected based on their yields. These have been defined as exhibiting grain protein deviation[3] and may provide a basis for the future development of wheat cultivars that require less nitrogen fertilization to achieve acceptable protein contents for breadmaking. Important to understand the relationship between N nutrition, grain protein content, grain protein composition, and processing properties

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