The sophisticated biochemical carbon-concentrating mechanism of C4 photosynthetic pathway enables the plants to survive in high temperatures, high light intensities, radiations and drought conditions. Although it was reported that C4 photosynthesis has independently evolved at least 66 times from C3 ancestors, the evolutionary trajectory was unclear. In this context, the genus Alloteropsis has been studied as it includes both C3 (A. semialata subspecies eckloniana) and C4 species (A. angusta, A. cimicina, and A. semialata subspecies semialata). Sequencing of transcriptomes followed by comprehensive phylogenetic analyses and molecular dating had shown multiple lateral acquisitions of key C4 genes in the Alloteropsis genus. These key genes have contributed to the adaptation of the primary metabolism, and their transmission was found to be independent of most of the genome. Thus, the report shows the plant-to-plant lateral transfer of nuclear genes to be one of the mechanisms of transmission of C4 traits among the Alloteropsis genus. (Summary by Muthamilarasan Mehanathan) Current Biology 10.1016/j.cub.2012.01.054