Evolution and Expression of the Membrane Attack Complex and Perforin Gene Family in the Poaceae

Membrane Attack Complex and Perforin (MACPF) proteins play crucial roles in plant development and plant responses to environmental stresses. To date, only fourMACPFgenes have been identified inArabidopsis thaliana, and the functions of theMACPFgene family members in other plants, especially in important crop plants, such as the Poaceae family, remain largely unknown. In this study, we identified and analyzed 42MACPFgenes from six completely sequenced and well annotated species representing the major Poaceae clades. A phylogenetic analysis ofMACPFgenes resolved four groups, characterized by shared motif organizations and gene structures within each group.MACPFgenes were unevenly distributed along the Poaceae chromosomes. Moreover, segmental duplications and dispersed duplication events may have played significant roles duringMACPFgene family expansion and functional diversification in the Poaceae. In addition, phylogenomic synteny analysis revealed a high degree of conservation among the PoaceaeMACPFgenes. In particular, Group I, II, and IIIMACPFgenes were exposed to strong purifying selection with different evolutionary rates. Temporal and spatial expression analyses suggested that Group IIIMACPFgenes were highly expressed relative to the other groups. In addition, mostMACPFgenes were highly expressed in vegetative tissues and up-regulated by several biotic and abiotic stresses. Taken together, these findings provide valuable information for further functional characterization and phenotypic validation of the PoaceaeMACPFgene family.