Genetic diversity for root plasticity and nitrogen uptake in wheat seedlings

Vanessa J. Melino*, Gabriele Fiene, Akiko Enju, Jinhai Cai, Peter Buchner, Sigrid Heuer

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

35 Scopus citations

Abstract

Enhancing nitrogen use efficiency (NUE) of wheat is a major focus for wheat breeding programs. NUE may be improved by identifying genotypes that are competitive for nitrogen (N) uptake in early vegetative stages of growth and are able to invest that N in grain. Breeders tend to select high yielding genotypes under conditions of medium to high N supply, but it is not known whether this influences the selection of root plasticity traits or whether, over time, breeders have selected genotypes with higher N uptake efficiency. To address this, genotypes were selected from CIMMYT (1966-1985) and Australian (1999-2007) breeding programs. Genotypes from both programs responded to low N supply by expanding their root surface area through increased total root number and/or length of lateral roots. Australian genotypes were N responsive (accumulated more N under high N than under low N) whereas CIMMYT genotypes were not very N responsive. This could not be explained by differences in N uptake capacity as shown by 15N flux analysis of two representative genotypes with contrasting N accumulation. Expression analysis of nitrate transporter genes revealed that the high-affinity transport system accounted for the majority of root nitrate uptake in wheat seedlings under both low and high N conditions.

Original languageEnglish (US)
Pages (from-to)942-956
Number of pages15
JournalFunctional Plant Biology
Volume42
Issue number10
DOIs
StatePublished - Jan 1 2015

Keywords

  • nitrate transporters
  • nitrate uptake.
  • root foraging

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Plant Science

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