The Agavoideae: an emergent model clade for CAM evolutionary biology

Crassulacean acid metabolism - or CAM photosynthesis - was described in the early to mid-20th century, and our understanding of this metabolic pathway was later expanded upon through detailed biochemical analyses of carbon balance. Soon after, scientists began to study the ecophysiological implications of CAM, and a large part of this early work was conducted in the genus Agave, in the subfamily Agavoideae of the family Asparagaceae. Today, the Agavoideae continues to be important for the study of CAM photosynthesis, from the ecophysiology of CAM species, to the evolution of the CAM phenotype and to the genomics underlying CAM traits. Here we review past and current work on CAM in the Agavoideae, in particular highlighting the work of Park Nobel in Agave, and focusing on the powerful comparative system the Agavoideae has become for studying the origins of CAM. We also highlight new genomics research and the potential for studying intraspecific variation within species of the Agavoideae, particularly species in the genus Yucca. The Agavoideae has served as an important model clade for CAM research for decades, and undoubtedly will continue to help push our understanding of CAM biology and evolution in the future.

Automated summary

Crassulacean acid metabolism, or CAM photosynthesis, was first described in the early to mid-20th century. Since then, scientists have conducted detailed biochemical analyses to further understand this metabolic pathway's carbon balance. The study of CAM in Agavoideae, particularly in the genus Agave, has provided valuable insights into CAM ecophysiology and the evolution of CAM traits. Additionally, new genomics research and the investigation of intraspecific variation within species of the Agavoideae, specifically in the genus Yucca, hold great potential for advancing our understanding of CAM biology and evolution.