Contributions of root uptake and remobilization to grain zinc accumulation in wheat depending on post-anthesis zinc availability and nitrogen nutrition
- 1.1k Downloads
Background and aims
Whether root Zn uptake during grain filling or remobilization from pre-anthesis Zn stores contributes more to grain Zn in wheat is subject to an on-going debate. This study investigated the effects of N nutrition and post-anthesis Zn availability on the relative importance of these sources.
Durum wheat plants were grown in nutrient solution containing adequate Zn (0.5 μM) and three different N levels (0.5; 1.5; 4.5 mM). One third of the plants were harvested when they reached anthesis. One half of the remaining plants were grown to maturity with adequate Zn, whereas the Zn supply to the other half was discontinued at anthesis. Roots, straw and grains were harvested separately and analyzed for Zn and N.
Depending on the N supply, Zn remobilization from pre-anthesis sources provided almost all of grain Zn when the Zn supply was withheld at anthesis; otherwise up to 100 % of grain Zn could be accounted for by Zn taken up post-anthesis. By promoting tillering and grain yield and extending the grain filling, higher N supply favored the contribution of Zn uptake to grain Zn accumulation.
Remobilization is critical for grain Zn accumulation when Zn availability is restricted during grain filling. However, where root uptake can continue, concurrent Zn uptake during grain development, favored by higher N supply, overshadows net remobilization.
KeywordsNitrogen Post-anthesis Remobilization Uptake Wheat Zinc
- Alloway BJ (2004) Zinc in soils and crop nutrition. International Zinc Association Publications, BrusselsGoogle Scholar
- Cakmak I, Engels C (1999) Role of mineral nutrients in photosynthesis and yield formation. In: Rengel Z (ed) Crop Nutrition. The Haworth Press, New York, pp 141–168Google Scholar
- Elias EM, Manthey FA (2005) End products: Present and future uses. In: DiFonzo N, Araus JL, Pfeiffer WH, Slafer GA, Royo C, Nachit MM (eds) Durum Wheat Breeding Current Approaches and Future Strategies. Food Products Press, New York, pp 63–86Google Scholar
- Hajiboland R, Singh B, Romheld V (2001) Retranslocation of Zn from leaves as important factor for zinc efficiency of rice genotypes. In: Horst WJ, Schenk MK, Burkert A, Claasen N, Flessa H, Frommer WB, Goldbach H, Olfs HW, Romheld V, Sattelmacher B, Schmidhalter U, Schubert S, von Wiren N, Wittenmayer L (eds) Plant Nutrition—Food Security and Sustainability of Agro-Ecosystems. Kluwer, Dordrect, pp 226–227Google Scholar
- Hotz C, Brown KH (2004) Assessment of the risk of zinc deficiency in populations and options for its control. Food Nutr Bull 25:94–204Google Scholar
- Lott JNA, Greenwood JS, Batten GD (1995) Mechanisms and regulation of mineral nutrient storage during seed development. In: Kigel J, Galili G (eds) Seed development and germination. Marcel Dekker, New York, pp 215–235Google Scholar
- Marschner H (1995) Mineral Nutrition of Higher Plants, 2nd edn. Academic, LondonGoogle Scholar
- Marschner P (2011) Marschner’s Mineral Nutrition of Higher Plants, 3rd edn. Academic, LondonGoogle Scholar