Transition from a maternal to external nitrogen source in maize seedlings

Sabermanesh, K., Holtham, L.R., George, J., Roessner, U., Boughton, B.A.ORCID: 0000-0001-6342-9814, Heuer, S., Tester, M., Plett, D.C. and Garnett, T.P. (2017) Transition from a maternal to external nitrogen source in maize seedlings. Journal of Integrative Plant Biology, 59 (4). pp. 261-274.

Abstract

Maximizing NO3− uptake during seedling development is important as it has a major influence on plant growth and yield. However, little is known about the processes leading to, and involved in, the initiation of root NO3− uptake capacity in developing seedlings. This study examines the physiological processes involved in root NO3− uptake and metabolism, to gain an understanding of how the NO3− uptake system responds to meet demand as maize seedlings transition from seed N use to external N capture. The concentrations of seed‐derived free amino acids within root and shoot tissues are initially high, but decrease rapidly until stabilizing eight days after imbibition (DAI). Similarly, shoot N% decreases, but does not stabilize until 12–13 DAI. Following the decrease in free amino acid concentrations, root NO3− uptake capacity increases until shoot N% stabilizes. The increase in root NO3− uptake capacity corresponds with a rapid rise in transcript levels of putative NO3− transporters, ZmNRT2.1 and ZmNRT2.2 . The processes underlying the increase in root NO3− uptake capacity to meet N demand provide an insight into the processes controlling N uptake.

Item Type:	Journal Article
Publisher:	John Wiley & Sons Australia, Ltd on behalf of Institute of Botany, Chinese Academy of Sciences
Copyright:	© 2017 The Authors
URI:	http://researchrepository.murdoch.edu.au/id/eprint/56329

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