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Algae
Root System
All algal flagella appear to possess flagellar roots, that is, microtubular or fibrillar, often crossbanded structures, which extend from the basal bodies into the cytoplasm either underlying the
plasma membrane or projecting into the cell and making contact with other organelles such as the
nucleus, the mitochondria, the Golgi apparatus, or the chloroplasts. Diverse functions have been
assigned to the flagellar roots: anchoring devices and/or stress absorbers; sensory transducers, skeletal, and organizational structures for morphogenetic processes.
The great diversity of morphology and arrangement of the flagellar root systems among the
different algae make it necessary to describe them separately in each division. As said above,
Cyanobacteria and Rhodophyta lack any flagellar apparatus, hence they will not be considered in
the following.
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
the four roots appear identical, each containing about 20 microtubules in Glaucocystis, and about
50 in Gloeochaete. 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 2.47).
Chlorophyta—Charophyta
Flagellar apparatus of most green algae are characterized by a cruciate root system. A cruciate root
system consists of four roots spreading out more or less evenly from the basal bodies and with opposite roots usually possessing identical numbers of microtubules. Since in most members of these two
phyla, two of the roots are two-stranded, the general arrangement of microtubular root follows the
X–2–X–2 system, with X varying from 3 to 8 microtubules.
The root system is cruciate with a 4–2–4–2 system in the tetraflagellate Pyramimonas
(Prasinophytes) and Tetraselmis (Chlorodendrophyceae), a 4–2–0–0 system in Mantoniella
FIGURE 2.47 Root system of Glaucophyta. AF: anterior flagellum; PF: posterior flagellum; MLS: multilayered structure.
Algae
Root System
All algal flagella appear to possess flagellar roots, that is, microtubular or fibrillar, often crossbanded structures, which extend from the basal bodies into the cytoplasm either underlying the
plasma membrane or projecting into the cell and making contact with other organelles such as the
nucleus, the mitochondria, the Golgi apparatus, or the chloroplasts. Diverse functions have been
assigned to the flagellar roots: anchoring devices and/or stress absorbers; sensory transducers, skeletal, and organizational structures for morphogenetic processes.
The great diversity of morphology and arrangement of the flagellar root systems among the
different algae make it necessary to describe them separately in each division. As said above,
Cyanobacteria and Rhodophyta lack any flagellar apparatus, hence they will not be considered in
the following.
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
the four roots appear identical, each containing about 20 microtubules in Glaucocystis, and about
50 in Gloeochaete. 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 2.47).
Chlorophyta—Charophyta
Flagellar apparatus of most green algae are characterized by a cruciate root system. A cruciate root
system consists of four roots spreading out more or less evenly from the basal bodies and with opposite roots usually possessing identical numbers of microtubules. Since in most members of these two
phyla, two of the roots are two-stranded, the general arrangement of microtubular root follows the
X–2–X–2 system, with X varying from 3 to 8 microtubules.
The root system is cruciate with a 4–2–4–2 system in the tetraflagellate Pyramimonas
(Prasinophytes) and Tetraselmis (Chlorodendrophyceae), a 4–2–0–0 system in Mantoniella
FIGURE 2.47 Root system of Glaucophyta. AF: anterior flagellum; PF: posterior flagellum; MLS: multilayered structure.