Fig. 1.

A conserved plant-specific COST1 (ID: AT2G45260) protein required for normal growth and development. (A) Schematic diagram of the structure of the COST1 protein; the conserved DUF641 domain is indicated at the N terminus (N); numbers below indicate the position of amino acids. (B) Phylogenetic analysis of COST proteins in different plant species. The numbers on the branch node refer to bootstrap value of the phylogenetic tree; 500 bootstrap replicates were performed. Dots denote the four Arabidopsis COST proteins, with COST1 shown in magenta. Fragments per kilobase of transcript per million mapped reads (FPKM) values of the four Arabidopsis COST genes are shown on the right based on the RNA-seq in this study. Protein IDs are listed after abbreviated species names. The full species names are (from top to bottom): Arabidopsis thaliana, Arabidopsis lyrata, Capsella rubella, Brassica rapa, Populus trichocarpa, Solanum lycopersicum, Medicago truncatula, Aquilegia coerulea, Brachypodium distachyon, Oryza Sativa, Zea mays, Amborella trichopoda, Picea abies, and Physcomitrella patens. Triangles represent hidden subtrees, which are shown in detail in SI Appendix, Fig. S2. (C) Analysis of expression of the Arabidopsis COST genes by qPCR. (D) Pleiotropic defects of a cost1 mutant. Four-week-old and 45-d-old WT and cost1 plants are shown in the Upper and Lower, respectively.