Charophycean Green Algae: What can charophycean green algal cell walls tell us about land plant cell
wall evolution?
(Collaborators: David Domoyzch, William Willats & Markus Pauly) |
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Land plants evolved from an ancestral pool of freshwater green algae
known as the charophycean green algae (CGA). CGA display morphological
forms that are simpler in construction than that of land plants,
however, many of the fundamental morphotypes displayed by land plants
are also found in the CGA. The cell wall (CW) of land plants is one of
the critical structures that must be accurately constructed and
modulated during various developmental events and under diverse
physiological conditions. The CW is an intricate network, constructed
primarily of polysaccharides and proteins, that is directly involved in
the expression of specific morphological forms and in essential
functions such as maintenance of structural integrity, cell-cell
communication, signal transduction, adhesion and physical/chemical
defense. Preliminary investigations of CGA CW polymers indicate
structural similarity to those of land plants, suggesting that many of
the key morphogenetic events and associated CW-biochemical properties
found in modern land plants arose in their ancestors before emergence
onto land approximately 470 million years ago. Elucidation of CW
biochemistry and development in the CGA is necessary if we hope to
understand the evolution of green plants and the development of modern
terrestrial plant form and function. The overall goal of our work is to
understand the function of CGA CW polymers critical to success of land
plants, and determine the evolutionary sequence that led to this result.
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