School of Biological Science, Monash University, Melbourne, Victoria 3800, Australia.
Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
Cold Spring Harb Perspect Biol. 2021 Jun 1;13(6):a040048. doi: 10.1101/cshperspect.a040048.
Indole-3-acetic acid, that is, auxin, is a molecule found in a broad phylogenetic distribution of organisms, from bacteria to eukaryotes. In the ancestral land plant auxin was co-opted to be the paramount phytohormone mediating tropic responses and acting as a facilitator of developmental decisions throughout the life cycle. The evolutionary origins of land plant auxin biology genes can now be traced with reasonable clarity. Genes encoding the two enzymes of the land plant auxin biosynthetic pathway arose in the ancestral land plant by a combination of horizontal gene transfer from bacteria and possible neofunctionalization following gene duplication. Components of the auxin transcriptional signaling network have their origins in ancestral alga genes, with gene duplication and neofunctionalization of key domains allowing integration of a portion of the preexisting transcriptional network with auxin. Knowledge of the roles of orthologous genes in extant charophycean algae is lacking, but could illuminate the ancestral functions of both auxin and the co-opted transcriptional network.
吲哚-3-乙酸，也就是生长素，是一种在广泛的生物进化谱系中都存在的分子，从细菌到真核生物。在原陆生植物中，生长素被共同选择为主要的植物激素，调节向性反应，并在整个生命周期中作为发育决策的促进剂。现在可以比较清楚地追溯陆生植物生长素生物学基因的进化起源。编码陆生植物生长素生物合成途径的两种酶的基因是通过细菌的水平基因转移和基因复制后的可能新功能化而在原陆生植物中产生的。生长素转录信号网络的组成部分起源于原藻类基因，通过关键结构域的基因复制和新功能化，允许将部分预先存在的转录网络与生长素整合。虽然现存的石莼藻类中同源基因的作用尚不清楚，但可以阐明生长素和共同选择的转录网络的祖先功能。
