Researchers report that some tropical trees can “breathe” at night by taking in carbon dioxide while keeping their pores closed during hot daytime conditions. The work focuses on three Clusia species—Clusia rosea, Clusia minor, and Clusia major—and describes how they survive drought by using water-saving forms of photosynthesis.
Across the studies, the key finding is that these carbon uptake strategies are not the result of a single evolutionary event. Instead, the research links the emergence of nighttime carbon dioxide uptake to ancient genomic duplication in Clusia, followed by long-term genetic reshuffling. The three species show different levels and types of the CAM (crassulacean acid metabolism) strategy, ranging from stronger CAM to forms that are triggered by stress or function as hybrids.
While one outlet emphasizes the role of genomic duplication in producing diverse photosynthetic responses, the other highlights the drought-related advantage of keeping pores closed to reduce water loss. Together, the reporting points to multiple evolutionary pathways within the same plant genus that enable survival under water scarcity.
