Page 95 - Algae Anatomy, Biochemistry, and Biotechnology

78 Algae: Anatomy, Biochemistry, and Biotechnology

FIGURE 2.51 Root system of Pavlovales (Haptophyta). AF, anterior flagellum; PF, posterior flagellum;
NSFR, nonstriated fibrous root; H, haptonema; HFR, haptonema fibrous root; 2SR, two-stranded root; 7SR,
seven-stranded root; FCB, fibrous connecting band; and N, nucleus.

connective, which links the proximal parts of the longitudinal root, the transverse striated root, and
the transverse and longitudinal basal bodies with the nucleus. Fibrous rings with cross-striations,
called fibrous collars, encircle the flagellar canals, the longitudinal striated collar less conspicuous
than the transverse striated collar. A non-striated fiber interconnects the two collars. The fibrous
elements of this complex root apparatus are likely to contain centrin (Figure 2.54).

Euglenophyta
Euglenoids show a rather uniform root structure, with one microtubular root opposite each basal
body and a single microtubular root in between, termed dorsal, intermediate, and ventral roots
(Figure 2.55). The dorsal root is anchored to the dorsal basal body at the side furthest from the
ventral basal body; the intermediate and ventral roots are both associated with the ventral basal
body at its dorsal and ventral sides, respectively. In Euglena mutabilis, the dorsal and the intermedi-
ate roots consist of three microtubules, while the ventral root consists of five microtubules; in E.
gracilis, the ventral root is formed by five microtubules as in E. mutabilis, while the microtubules
of the dorsal root are more numerous. These roots extend from the basal bodies along the reservoir
and into the cytoplasm, usually along the cell periphery, but in some species towards the nucleus.
Flagellar roots are believed to play an important role in maintaining the cell shape. In some species
the two flagellar basal bodies are connected by a conspicuous transversely striated connective.