Cell surface inCalluna vulgaris L. hair roots

Structure and composition of the thick wall in hair root epidermal cells of Woollsia pungens

“…Similar results were obtained in Calluna vulgaris hair root epidermal cells (Peretto et al, 1990;Perotto et al, 1995). This contrasts with the strong binding to the cortical and stelar cell walls, indicating relatively high amounts of unesterified and esterified pectins, a difference also found in roots of members of Gramineae and Chenopodiaceae (Knox et al, 1990), as well as C. vulgaris hair roots (Peretto et al, 1990) and mycorrhizal roots of Allium porrum cv Mastro di Carenta (Bonfante-Fasolo et al, 1990). A range of other species, including carrot roots do not show this difference between epidermal and other root cells (Perotto et al, 1997).…”

“…The low level of binding to JIM7 indicates low levels of esterified pectin as well , at least with the JIM7 epitope. Similar results were obtained in Calluna vulgaris hair root epidermal cells (Peretto et al, 1990;Perotto et al, 1995). This contrasts with the strong binding to the cortical and stelar cell walls, indicating relatively high amounts of unesterified and esterified pectins, a difference also found in roots of members of Gramineae and Chenopodiaceae , as well as C. vulgaris hair roots (Peretto et al, 1990) and mycorrhizal roots of Allium porrum cv Mastro di Carenta .…”

“…The anatomy of the hair roots of W. pungens is consistent with previous descriptions for hair roots in the Ericaeae and Epacridaceae. The root surface is covered with a mucilaginous sheath as seen in other members of these two families (Leister, 1968;Bonfante-Fasolo & Gianinazzi-Pearson, 1979;Peretto et al, 1990;Ashford et al, 1996). The outermost cell layer of the hair roots is shown to be a true epidermis as in other species examined (cf.…”

“…The data indicate that the thick wall laid down in W. pungens epidermal cells is a secondary wall with a typical multilamellate arrangement of microfibrils. Epidermal cells of Calluna vulgaris L. (Ericales) hair roots are also reported to develop helicoidal walls (Peretto et al, 1990;Perotto et al, 1995). The common denominator for the differentiation of a helicoidal-type secondary wall appears to be cell size and shape; cells with diameters between 15 and 60 µm lay down a helicoidal pattern (Emons & Kieft, 1994).…”

The epidermal surface of the maize root tip

“…Whole roots were used so only surface was stained, From Bacic et al (1986), These authors attributed the staining patterns described to the elongation zone of their roots. Their micrographs indicate mainly the region of columnar epidermal cells and a very small portion of the region where they begin to elongate periclinally, ' Antibody directed against a-L-arabinofuranosyl, (position 8, Fig, 1), tbe most proximal region examined in tbis study, A similar belicoidal primary wall was recently described in tbe same location in tbe surface of tbe bair roots of Calluna vulgaris L, (Peretto et al, 1990), Tbe inner layer of tbe pellicle (L2) bas usually been seen as distinct from tbe adjacent cell wall (LI), tbougb interpretations of its nature and affinity have differed greatly (see Table 1), Tbe marked differences in organization and staining properties of tbe component matrix and microfibrils of tbose layers observed witb tbe electron microscope are seen clearly only in quite tbin sections cut obliquely to tbe surface and optimally stained. Even in sucb sections tbe boundary between tbe layers is often unclear, particularly wbere tbe epidermal cells are elongating, Tbere are, bowever, numerous differences in tbe staining properties of tbe wall and tbe inner pellicle (Table 2; Miki et al, 1980;tables 2, 3;Vermeer & McCully, 1982;table 1), altbougb many of tbese are differences only of degree (e,g, botb layers are PASpositive but tbe walls are more strongly stained), Tbe most consistent staining difference is, as noted earlier, for acidic polysaccbarides wbicb are indicated in tbe wall but not in tbe inner pellicle, Tbis difference, bowever, disappears after pectin metbyl esterase treatment, wbicb induces metacbromasy in tbe previously unstained L2 layer (Miki et al, 1980), suggesting a difference only in degree of metbylation of tbe acid groups present, Lectin and specific antibody binding bave, bowever, also indicated considerable differences in tbe terminal sugar residues predominating in tbe two layers (Table 2; Guinel & McCully, 1985;Bacic et al, 1986, fig.…”