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Transition from a maternal to external nitrogen source in maize seedlings

Maximizing NO(3) (−) 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 NO(3) (−) uptake capacity in developing seedlings. This study examines the phys...

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Detalles Bibliográficos
Autores principales: Sabermanesh, Kasra, Holtham, Luke R., George, Jessey, Roessner, Ute, Boughton, Berin A., Heuer, Sigrid, Tester, Mark, Plett, Darren C., Garnett, Trevor P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5413817/
https://www.ncbi.nlm.nih.gov/pubmed/28169508
http://dx.doi.org/10.1111/jipb.12525
Descripción
Sumario:Maximizing NO(3) (−) 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 NO(3) (−) uptake capacity in developing seedlings. This study examines the physiological processes involved in root NO(3) (−) uptake and metabolism, to gain an understanding of how the NO(3) (−) 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 NO(3) (−) uptake capacity increases until shoot N% stabilizes. The increase in root NO(3) (−) uptake capacity corresponds with a rapid rise in transcript levels of putative NO(3) (−) transporters, ZmNRT2.1 and ZmNRT2.2. The processes underlying the increase in root NO(3) (−) uptake capacity to meet N demand provide an insight into the processes controlling N uptake.