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Cell walls of seed hairs from Lygeum spartum: ultrastructure, composition and mechanical properties

Zeriahene, N., Prat, R., Goldberg, R., Catesson, A.M., Harche-Kaid, M.
Annals of botany 1998 v.81 no.1 pp. 61-66
Poaceae, cell walls, provenance, polysaccharides, cellulose, cinnamic acid, arid zones, semiarid zones, mechanical properties, cytoplasm, testa, hemicellulose, chemical constituents of plants, Algeria
The silky hairs covering the whole surface of Lygeum spartum dispersal units are unicellular, unlignified epidermal structures whose length varies from 5 to 17 mm. The cell walls present a stratified texture after extraction of matrix material. Their composition depends on the geographical origin of the grasses. Polysaccharides extracted with boiling water represent approx. 18% of the cell wall dry matter in samples harvested in Algerian arid high-plateaus and only 3% in samples harvested in semi-arid coastal zones. In the latter case, hemicellulose and cellulose contents amounted to approx. 50 and 40%, respectively. Slightly lower values were found in high-plateau samples. Cinnamic acids were detected only in coastal region specimens which exhibited a higher mechanical resistance and a lower extensibility. These results support the existence of two distinct populations colonizing arid or semi-arid areas respectively.