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Phosphate absorption by excised ordinary and proteoid roots of Protea compacta R. Br.

1986; Elsevier BV; Volume: 52; Issue: 6 Linguagem: Inglês

10.1016/s0254-6299(16)31490-9

1727-9321

A. J. E. Smith, J.H. Jooste,

Algal biology and biofuel production

Over the temperature range of 15 to 35 °C the highest phosphate absorption by proteoid roots occurred at 35 °C whereas in the case of ordinary roots absorption increased over the entire temperature range. Desorption revealed that a greater fraction of the absorbed phosphate in ordinary roots apparently occurs in the free space. Phosphate absorption, especially by proteoid roots, was increased by the addition of sugars. Proteoid roots were not consistently characterized by higher phosphate absorption than the ordinary roots. Sugars had no significant effect on oxygen uptake by both types of roots, but proteoid roots displayed a higher oxygen uptake than ordinary roots. The results indicate that proteoid roots are metabolically more active than ordinary roots, and that metabolic processes are to a greater extent involved in ion absorption by proteoid than by ordinary roots. Oor die temperatuurgebied van 15 tot 35 °C het die grootste opname van fosfaat deur proteoïede wortels by 25 °C plaasgevind, terwyl in die geval van gewone wortels opname oor die hele temperatuurgebied toegeneem het. Desorpsie het aan die lig gebring dat ’n groter fraksie van die opgeneemde fosfaat in gewone wortels klaarblyklik in die vrye ruimte voorkom. Fosfaatopname, veral deur proteoïede wortels, is deur die byvoeging van suikers verhoog. Proteoïede wortels is nie deurgaans deur ’n hoër fosfaatopname as die gewone wortels gekenmerk nie. Suikers het geen betekenisvolle invloed op suurstofopname deur albei wortelsoorte gehad nie, maar proteoïede wortels het ’n hoër suurstofopname as gewone wortels vertoon. Die resultate toon dat proteoïede wortels metabolies meer aktief as gewone wortels is, en dat metaboliese prosesse tot ’n groter mate in ioonopname deur proteoïede as gewone wortels betrokke is.