Carbohydrates in Colobanthus quitensis and Deschampsia antarctica

Abstract

Eight to nineteen ethanol-soluble carbohydrate components were identified in vegetative tissues of Colobanthus quitensis and Deschampsia antarctica. The analysed carbohydrates included: monosaccharides, cyclitols, galactosyl cyclitols, raffinose family oligosaccharides, lichnose family oligosaccharides, kestose family oligosaccharides. The analysed vegetative tissues accumulated from 447 to 139 mg/g d.m. soluble carbohydrates in Colobanthus quitensis, Deschampsia antarctica respectively. The raffinose family oligosaccharides constituted 53.3% in Colobanthus quitensis of the identified soluble carbohydrate component pool. Vegetative tissues accumulated starch in Colobanthus quitensis 20.6 mg/g d.m. and 261.6 mg/g d.m. in Deschampsia antarctica. Anatomical and ultrastructural observations of vegetative part of Colobanthus quitensis and Deschmpsia antarctica revealed the presence of various ergastic materials in intercellular spaces, cell walls and protoplasts. Various parts of these plants contain insoluble, PAS positive polysaccharides in intercellular spaces and in cell walls. Chloroplasts of analysed tissues contained starch. Less starch was visible in young, growing parts of shoots of Colobanthus quitensis and Deschmpsia antarctica, more starch appears in mature, differentiated parts.