Changes in soluble carbohydrates and soluble proteins in three arid- zone grass species under salt stress
Keywords:Arid-zone grasses, Soluble carbohydrates, Monosaccharides, Disaccharides, Trisaccharides, Soluble proteins
AbstractThree arid-zone grass species, Cenchrus pennisetiformis Hochst. & Steud., Leptochloa fusca (L) Kunth and Panicum turgidum Forssk were grown for six weeks in sand culture salinized with 0 (control) or 150 mol m-3 NaCl. Shoot fresh and dry biomass of C. pennisetiformis and P. turgidum decreased significantly in the salt treatment, whereas those of L. fusca remained almost unaffected. Cenchrus pennisetiformis and P. turgidum had similar levels of leaf monosaccharides (glucose + fructose) in both the control and salt treatments. Of the three species, L. fusca was the lowest in accumulation of monosaccharides, although its levels of monosaccharides doubled in the salt treatment compared with that in the control. Disaccharides (sucrose), in the leaves of C. pennisetiformis, decreased markedly due to the addition of salt in the rooting medium. Trisaccharides (raffinose) were very low in the three species in relation to monosaccharides or disaccharides. Total soluble leaf proteins in both C. pennisetiformis and L. fusca decreased in the salt treatment compared with those in the control and was marked in C. pennisetiformis. In contrast, soluble leaf proteins of P. turgidum increased considerably in the salt treatment.