P0743The Grass Tribe Paniceae and the Evolution of C4 Photosynthesis
The Grass Tribe Paniceae and the Evolution of C4 Photosynthesis
Most plants convert sunlight into chemical energy using C3 photosynthesis. However, a modified pathway, C4 photosynthesis, allows some plants to be more drought tolerant and fertilizer-use efficient. Strikingly, C4 photosynthesis has evolved independently in dozens of different plant lineages, a testament to its diversity and advantages in many common terrestrial environments. Currently, massive international efforts are focused on breeding and bioengineering C4 photosynthesis into C3 rice and other food and sustainable energy crops. What these efforts often overlook is that there is no “one” C4 photosynthesis. In fact, with its 60-plus distinct evolutionary origins, 20-plus anatomies, and 3 basic enzymatic sub-types, C4 is more of a diverse syndrome than it is one generalized photosynthesis type. Because the various C4 sub-types have evolved in diverse environments, different sub-types may be more efficient for different agricultural applications. Our study uses the grass tribe Paniceae to investigate the evolution and diversity of C4 photosynthesis within a phylogenomic context. The Paniceae are ideal for this investigation because they are the only plant lineage with representatives that primarily utilize each of the C4 enzymatic subtypes. This allows us to answer questions such as: How are different types of C4 photosynthesis related to each other? Which C3 and C4 species are ideal model organisms for studying C4 evolution in the Paniceae? Which tribe Paniceae species are best suited for development as sustainable energy, food, health, and forage crops?