Viridiplantae and Algae

Recent research on plant glycan structure and function has typically emphasized model plants such as and plants of commercial importance. However, there is increasing interest in studying the glycans produced by plants from all the major orders of the Viridiplantae. Such studies, together with the availability of transcriptomic data for numerous green algae and land plants, have begun to reveal a rich diversity in glycan structures and insight into how some of these structures have changed during the evolution of the Viridiplantae. In this chapter, we provide an overview of the current knowledge of green plant glycan structures with an emphasis on the features that are unique to land plants. Viridiplantae (green plants) are a clade of photosynthetic organisms that contain chlorophylls a and b, produce and store their photosynthetic products inside a double-membrane-bounded chloroplast, and have cell walls that typically contain cellulose. The Viridiplantae are comprised of two clades—the Chlorophyta and the Streptophyta. The Chlorophyta contain most of the organisms typically referred to as “green algae.” The term “algae” is also used for several other groups of photosynthetic eukaryotes, including diatoms and the red, brown, golden, and yellow-green algae. The Streptophyta comprise several other lineages that are also referred to as “green algae” and the land plants. Land plants include the liverworts, mosses, hornworts, lycopods, ferns, gymnosperms, and flowering plants.