Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2057102 | Journal of Plant Physiology | 2008 | 13 Pages |
SummaryGlycosyl composition and linkage analysis of cell wall polysaccharides were examined in apical root zones excised from water-stressed and unstressed wheat seedlings (Triticum durum Desf.) cv. Capeiti (“drought-tolerant”) and cv. Creso (“drought sensitive”). Wall polysaccharides were sequentially solubilized to obtain three fractions: CDTA+Na2CO3 extract, KOH extract and the insoluble residue (α-cellulose). A comparison between the two genotypes showed only small variations in the percentages of matrix polysaccharides (CDTA+Na2CO3 plus KOH extract) and of the insoluble residues (α-cellulose) in water-stressed and unstressed conditions. Xylosyl, glucosyl and arabinosyl residues represented more than 90 mol% of the matrix polysaccharides. The linkage analysis of matrix polysaccharides showed high levels of xyloglucans (23–39 mol%), and arabinoxylans (38–48 mol%) and a low amount of pectins and (1→3), (1→4)-β-d-glucans. The high level of xyloglucans was supported by the release of the diagnostic disaccharide isoprimeverose after Driselase digestion of KOH-extracted polysaccharides. In the “drought-tolerant” cv. Capeiti the mol% of side chains of rhamnogalacturonan I and II significantly increased in response to water stress, whereas in cv. Creso, this increase did not occur. The results support a role of the pectic side chains during water stress response in a drought-tolerant wheat cultivar.