Agronomy and Horticulture, Department of
ORCID IDs
Document Type
Article
Date of this Version
10-2009
Citation
Journal of Experimental Botany, Vol. 60, No. 15, pp. 4263–4274
doi:10.1093/jxb/erp257
Abstract
The NAM-B1 gene is a NAC transcription factor that affects grain nutrient concentrations in wheat (Triticum aestivum). An RNAi line with reduced expression of NAM genes has lower grain protein, iron (Fe), and zinc (Zn) concentrations. To determine whether decreased remobilization, lower plant uptake, or decreased partitioning to grain are responsible for this phenotype, mineral dynamics were quantified in wheat tissues throughout grain development. Control and RNAi wheat were grown in potting mix and hydroponics. Mineral (Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn) and nitrogen (N) contents of organs were determined at regular intervals to quantify the net remobilization from vegetative tissues and the accumulation of nutrients in grain. Total nutrient accumulation was similar between lines, but grain Fe, Zn, and N were at lower concentrations in the NAM knockdown line. In potting mix, net remobilization of N, Fe, and Zn from vegetative tissues was impaired in the RNAi line. In hydroponics with ample nutrients, net remobilization was not observed, but grain Fe and Zn contents and concentrations remained lower in the RNAi line. When Fe or Zn was withheld post-anthesis, both lines demonstrated remobilization. These results suggest that a major effect of the NAM genes is an increased efflux of nutrients from the vegetative tissues and a higher partitioning of nutrients to grain.
Table S1
Waters 2009 JEB Wheat (Triticum aestivum) NAM proteins SUPP MAT 2.xls (52 kB)
Table S2
Waters 2009 JEB Wheat (Triticum aestivum) NAM proteins SUPP MAT 3.xls (27 kB)
Table S3
Waters 2009 JEB Wheat (Triticum aestivum) NAM proteins SUPP MAT 4.pdf (93 kB)
Figure S1
Waters 2009 JEB Wheat (Triticum aestivum) NAM proteins SUPP MAT 5.pdf (66 kB)
Figure S2
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Comments
Copyright 2009 Brian M. Waters, Cristobal Uauy, Jorge Dubcovsky, and Michael A. Grusak. Used by permission.