title: Origin and evolution of genes related to ABA metabolism and its signaling pathways.
abstract: Since plants cannot move to avoid stress, they have sophisticated acclimation mechanisms against a variety of abiotic stresses. The phytohormone abscisic acid (ABA) plays essential roles in abiotic stress tolerances in land plants. Therefore, it is interesting to address the evolutionary origins of ABA metabolism and its signaling pathways in land plants. Here, we focused on 48 ABA-related Arabidopsis thaliana genes with 11 protein functions, and generated 11 orthologous clusters of ABA-related genes from A. thaliana, Arabidopsis lyrata, Populus trichocarpa, Oryza sativa, Selaginella moellendorffii, and Physcomitrella patens. Phylogenetic analyses suggested that the common ancestor of these six species possessed most of the key protein functions of ABA-related genes. In two species (A. thaliana and O. sativa), duplicate genes related to ABA signaling pathways contribute to the expression variation in different organs or stress responses. In particular, there is significant expansion of gene families related to ABA in evolutionary periods associated with morphological divergence. Taken together, these results suggest that expansion of the gene families related to ABA signaling pathways may have contributed to the sophisticated stress tolerance mechanisms of higher land plants.
authors.affiliation: Gene Discovery Research Group, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. kohanada@psc.riken.jp
authors.forename: Kousuke
authors.initials: K
authors.lastname: Hanada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hase
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Toyoda
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
authors.forename: Masanori
authors.initials: M
authors.lastname: Okamoto
mesh_terms: D000040:Abscisic Acid / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D019068:Bryopsida / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D020131:Genes, Duplicate; D017343:Genes, Plant; D046228:Microarray Analysis; D005810:Multigene Family; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000235:genetics / Q000378:metabolism; D032503:Selaginellaceae / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D010937:Plant Growth Regulators; D000040:Abscisic Acid