Many plants have independently evolved C4 photosynthesis, concentrating CO2 within leaves to thrive in CO2-limited conditions and boost productivity in the tropics. Its significance has driven intense research, often comparing distantly related C4 and non-C4 plants. (2/7)

However, Alloteropsis semialata, a grass species, challenges this fixed photosynthetic type. It exhibits populations with ancestral C3 states in southern Africa, intermediate populations in the Zambezian region, and C4 populations across the paleotropics. (3/7)

Authors compiled Alloteropsis genus's distribution and evolutionary history and discuss how they have greatly contributed to our understanding of C4 evolution. A chromosome-level reference genome for a C3 individual was developed and compared it to a C4 accession of A. semialata. (4/7)

The evolutionary history of A. semialata involves independent origins of C4 photosynthesis, with different lineages using distinct anatomical and biochemical components for the C4 pathway. Hybridization and gene flow contributed to these diversification within A. semialata. (5/7)

Comparative analysis revealed high synteny between the C3 and C4 genomes of Alloteropsis semialata. Since the divergence of different photosynthetic groups, these genomes have experienced modest gene duplication and translocation. (6/7)