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Inula viscosa (syn Dittrichia viscosa) (sticky fleabane) from the Asteraceae family, is well-known for its pharmacological activities. In this research, anatomical characterization of leaves and stems of Inula viscosa plants revealed a considerable heterogeneity in their cell walls. Cell walls were isolated separately from leaves and stems and subjected to sequential extractions with boiling water, oxalate ammonium, KOH and NaOH solutions. The four polysaccharide fractions obtained were comparatively analysed using gas chromatography-flame ionization detector (GC-FID) and Fourier Transform Infrared–Attenuated Total Reflectance (ATR-FTIR) spectroscopy. The findings showed that the polysaccharides were unevenly distributed in the two organs. ATR-FTIR data reflected a higher proportion of pectins in stems relative to leaves in both fractions. Pectic fractions (hot water soluble and oxalate soluble fractions) seemed to be mainly composed by homogalacturonan and rhamnogalacturonan, with a residual presence of inulin. Hemicellulose (KOH and NaOH) fractions, instead, were rich in xylans, and still contained a low proportion of pectic polysaccharides. ATR-FTIR data pointed to a higher proportion of xylans in stems than in leaves. Finally, attending the molecular mass of cell wall polysaccharides from leaves, pectin fractions showed the presence of populations of polysaccharides with lower molecular masses than those of hemicellulose fractions. [ABSTRACT FROM AUTHOR]

The occurrence, localization, and properties of xyloglucan in the cell walls of growing regions of Pinus pinaster hypocotyls have been studied. Xyloglucan was released from the cell wall with alkali solutions, the concentration increasing from 4 through 35% KOH. In vitro experiments showed that xyloglucan and cellulose can interact, forming a macromolecular complex. Electron microscope observations showed that the cell wall material extracted with 35% KOH, which contained some amount of xyloglucan, was enough to cover and join the cellulose microfibrils. [ABSTRACT FROM AUTHOR]

Glycanases associated with the cell walls of Pinus pinaster Aiton from Northern Spain (29QT638, altitude 1000 m) were extracted with a 1 M LiCl solution, and their effect on the hemicellulosic polysaccharides from the same material was studied. The extracted proteins were able to increase the amount of reducing sugars and to decrease the viscosity of the hemicellulosic polysaccharides extracted with both 4 and 24% (w/v) KOH, suggesting the presence of exo- and endo-type glycanases. The extracted proteins released arabinose, galactose and xylose from both hemicellulosic polysaccharides, and caused an important depolymerization of xyloglucan. The results indicate that the changes in the hemicellulosic polysaccharides, i.e., xyloglucan depolymerization, found during cell elongation are caused by an enzymic system associated with the cell wall. [ABSTRACT FROM AUTHOR]

The changes in the endogenous growth as well as in the cell wall composition were studied along the hypocotyl of Pinus pinaster Aiton. Cell elongation decreased as the distance from the cotyledonary node increased. Pectic polysaccharides underwent an important depolymerization accompanied by a decrease in their uronic acid content from the apical to basal region of the hypocotyl. Additionally, the molecular mass of pectic polysaccharides strongly decreased from the apical to the basal regions. Watersoluble hemicellulosic polysaccharides extracted with 4% KOH decreased notably from the cotyledonary node towards the base, while water-soluble polysaccharides extracted with 24% KOH showed few differences along the hypocotyl. The molecular mass of xyloglucan present in both hemicellulosic fractions was lower in the upper hypocotyl region as compared with the basal region. These findings are in agreement with an active xyloglucan depolymerization in the upper region as would be expected in a region exhibiting very active growth. [ABSTRACT FROM AUTHOR]