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Plant function and evolutionary biology
REVIEW

Genetic approaches to enhancing nitrogen-use efficiency (NUE) in cereals: challenges and future directions

Trevor Garnett A B , Darren Plett A B C , Sigrid Heuer A B and Mamoru Okamoto A B
+ Author Affiliations
- Author Affiliations

A Australian Centre for Plant Functional Genomics, School of Agriculture Food and Wine, University of Adelaide, Adelaide, SA 5064, Australia.

B School of Agriculture, Food and Wine, University of Adelaide, Adelaide, SA 5064, Australia.

C Corresponding author. Email: darren.plett@acpfg.com.au

Functional Plant Biology 42(10) 921-941 https://doi.org/10.1071/FP15025
Submitted: 2 February 2015  Accepted: 24 June 2015   Published: 3 August 2015

Abstract

Over 100 million tonnes of nitrogen (N) fertiliser are applied globally each year to maintain high yields in agricultural crops. The rising price of N fertilisers has made them a major cost for farmers. Inefficient use of N fertiliser leads to substantial environmental problems through contamination of air and water resources and can be a significant economic cost. Consequently, there is considerable need to improve the way N fertiliser is used in farming systems. The efficiency with which crops use applied N fertiliser – the nitrogen-use efficiency (NUE) – is currently quite low for cereals. This is the case in both high yielding environments and lower yielding environments characteristic of cereal growing regions of Australia. Multiple studies have attempted to identify the genetic basis of NUE, but the utility of the results is limited because of the complex nature of the trait and the magnitude of genotype by environment interaction. Transgenic approaches have been applied to improve plant NUE but with limited success, due, in part, to a combination of the complexity of the trait but also due to lack of accurate phenotyping methods. This review documents these two approaches and suggests future directions in improving cereal NUE with a focus on the Australian cereal industry.

Additional keywords: biotechnology, fertiliser, metabolism.


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