Effects of salinity and phosphate on ion distribution in lupin leaflets

Autor: Reinhard F. M. Van Steveninck, Michael T. Treeby
Rok vydání: 1988
Předmět:
Zdroj: Physiologia Plantarum. 73:317-322
ISSN: 1399-3054
0031-9317
DOI: 10.1111/j.1399-3054.1988.tb00604.x
Popis: Lupin (Lupinus luteus L. cv. Weiko III) were grown in nutrient solution over a range of inorganic phosphate (Pi) concentrations, with or without 50 mM NaCl. Plants with high Pi (2 mM) and salt showed progressive leaf necrosis and had higher concentrations of total phosphate than plants grown with high Pi alone. Most of the extra total phosphate in salt treated plants was in the Pi form. Pi supply did not influence Na+, K+ or Cl− concentrations in epidermal vacuoles or mesophyll cells. However, epidermal vacuoles accumulated more monovalent cations (Na+ and K+) than Cl−, and in vacuoles of plants grown with 0.1 mM Pi additional Pi was accumulated, possibly to maintain charge balance. Plants grown with 2 mM Pi did not accumulate additional Pi in epidermal vacuoles, but showed higher phosphorus levels in cell walls. It is suggested that at moderate phosphorus concentrations Pi plays a role in epidermal osmotic adjustment, possibly explaining the beneficial role of additional phosphorus on salt stressed plants. At high Pi supply with salt, Pi does not contribute to osmotic adjustment and instead accumulates in cell walls. However, the cause of leaf damage under conditions of high phosphorus supply and salinity is still not entirely clear.
Databáze: OpenAIRE
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