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74                                    Algae: Anatomy, Biochemistry, and Biotechnology

                  Glaucophyta

                  In the cyanelle-containing genera Gloeochaete and Glaucocystis, four roots are arranged in a cruciate
                  manner, that is, four roots spreading out more or less evenly from the basal bodies. All four roots
                  appear identical, each containing about 20 microtubules in Glaucocystis, and about 50 in Gloeo-
                  chaete. In Cyanophora the roots are two. In all the genera each root contains a multilayered structure
                  consisting of a band of microtubules, which overlies several layers of parallel plates (Figure 2.48).

                  Heterokontophyta

                  The root system will be described for each class of this division, selecting when possible a genus
                  representing the morphological cell type within the class.
                     The root system of Ochromonas can be considered the basic type of the Chrysophyceae. A
                  single large cross-banded contractile root, termed rhizoplast, is typically present, associated with
                  the basal body of the longer pleuronematic flagellum. After leaving the basal body, this fibrous
                  root passes closely against the edge of the chloroplast and reaches the tip of the pyriform
                  nucleus. It then splits into several branches, ramifying over the nuclear surface, with some branches
                  located in the narrow space between the nucleus and the associated Golgi body. Four microtubular
                  roots, R1, R2, R3, and R4, anchor the two flagella in the cell, R1 and R2 are associated with the
                  basal body of the long pleuronematic flagellum, and R3 and R4 are associated with the basal
                  body of the short smooth flagellum. The three-stranded R1 describes an arc in the anterior part
                  of the cell just beneath the cell membrane. The two-stranded R2 originates at the opposite side
                  of the basal body, running along the cell membrane. R3 and R4, consisting of a species-specific
                  number of microtubules, arise from the opposite sides of the basal body of the short flagellum,






































                  FIGURE 2.48 Root system of Glaucophyta. AF, anterior flagellum; PF, posterior flagellum; and MLS,
                  multilayered structure.
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