Abstract :
Keywords PINOID; Auxin; Geotropism; AGCVIII gene family; Evolution; Whole genome duplication; Dispersed duplications; Transposable elements Highlights * 'Hypothetical Kinases' originated the earliest in the evolutionary process of AGCVIII kinase family, and then these kinases differentiated their functions and D6PK started to appear in moss, PINOID and PINOID2 started to appear in angiosperms pioneer plant Amborella trichopoda. * Pinoid gene family experienced complex evolutionary history accompanied by many gene gain and gene loss events during plant evolution. * Whole genome duplications and dispersed duplications play important role in the evolution of Pinoid gene family. Abstract PINOID is a kinase belonging to the AGCVIII family, which regulates the polar distribution of PIN proteins and plays an important role in plant geotropism. However, the origin and evolutionary history of this gene family is not fully known. In this study, we identified 79 similar sequences across 17 plant species genomes (PINOID, D6PK, PINOID2, "hypothetical kinase"). Our results show that the AGCVIII kinase family may have originated from related "Hypothetical Kinases" that come out sister to the rest of the gene family members. These kinases differentiated their functions are found in different plant classes: D6PK in moss and PINOID and PINOID2 evolving in angiosperms including the pioneer plant Amborella trichopoda. Our study investigates the evolution of PINOID kinases from a phylogenetic perspective giving us insight into how this important plant signal transduction network switch evolved to play a fundamental and important function in plant growth and development. We highlight the importance of whole genome duplications and dispersed duplications as opposed to tandem duplications in the evolution of this gene family. Abbreviations PID, PINOID; HL, hydrophilic loop; PKA, cyclic AMP dependent kinase; PKG, cGMP-dependent kinases; PKC, diacylglycerol-activated/phospholipid-dependent kinase; Ka, nonsynonymous substitutions per non-synonymous site; Ks, synonymous substitutions per synonymous site; Mc, Micromonas commoda; Mpo, Marchantia Polymorpha; Pp, Physcomitrella patens; Sc, Salvinia cucullata; Atr, Amborella trichopoda; Nc, Nymphaea colorata; Os, Oryza sativa; Ha, Helianthus annuus; Ls, Lactuca sativa; Vv, Vitis vinifera; Cm, Cucumis melo; Ptr, Populus trichocarpa; Ga, Gossypium arboreum; Ath, Arabidopsis thaliana; Cs, Camelina sativa Author Affiliation: (a) State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou, China (b) Department of Biology, California State University East Bay, Hayward, CA, United States of America (c) State Key Laboratory of Pharmaceutical Biotechnology, Department of Biotechnology and Pharmaceutical Sciences, School of Life Sciences, Nanjing University, Nanjing, China * Corresponding author. Article History: Received 23 November 2021; Revised 5 April 2022; Accepted 14 April 2022 (miscellaneous) Edited by: John Doe Byline: Jiangshan Bai (a), Michael J. Song (b), Jian Gao (c), Guiting Li [ligt18@lzu.edu.cn] (a,*)