Control of salt transport form roots to shoots of wheat in saline soil

Date

2004

Authors

Husain, Shazia
von Caemmerer, Susanne
Munns, Rana Ellen

Journal Title

Journal ISSN

Volume Title

Publisher

CSIRO Publishing

Abstract

Wheat genotypes with 5-fold difference in shoot Na+ concentrations were studied over a salinity range of 1-150 mM NaCl and CaCl 2 of 0.5-10 mM to assess their performance in saline and sodic soils. All genotypes had a maximum shoot Na+ concentration at 50 mM external NaCl when the supplemental Ca2+ provided an activity of 1 mM or more. Shoot Na+ concentrations either stayed constant from 50 to 150 mM external NaCl, or decreased in some genotypes at the higher salinity. Calculated rates of root uptake, and root: shoot transport, were at a maximum at 50 mM NaCl in all genotypes, and decreased at higher NaCl in some genotypes, indicating feedback regulation. K+ showed a pattern inverse to that of Na+. Cl- uptake and transport rates increased linearly with increasing salinity, and differed little between genotypes. Increasing external Ca2+ concentration reduced the accumulation of Na + in the shoot, the effects being greater in the low Na+ genotypes, and greater as the salinity increased, indicating that the plateau in shoot Na+ concentration relied on the maintenance of a minimal Ca2+ activity of 1 mM. Increasing external Ca2+ concentration did not reduce the root Na+ concentration, however, suggesting that Ca2+ influenced the loading of Na+ in the xylem.

Description

Keywords

Keywords: Genes; Salinity measurement; Sodium chloride; Soils; Transport properties; Saline soil; Sodic soils; Crops; salinity tolerance; wheat; Genotypes; Roots; Salinity; Shoots; Sodium Chloride; Soil; Wheat; Triticum aestivum Salt sensitive; Salt tolerant; Wheat

Citation

Source

Functional Plant Biology

Type

Journal article

Book Title

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2037-12-31