Ancient duplications and grass-specific transposition influenced the evolution of LEAFY transcription factor genes

First author: Bei Gao; Affiliations: The Chinese University of Hong Kong (香港中文大学): Hong Kong, China

Corresponding author: Jianhua Zhang 

The LFY transcription factor gene family are important in the promotion of cell proliferation and floral development. Understanding their evolution offers an insight into floral development in plant evolution. Though a promiscuous transition intermediate and a gene duplication event within the LFY family had been identified previously, the early evolutionary path of this family remained elusive. Here, we reconstructed the LFY family phylogeny using maximum-likelihood and Bayesian inference methods incorporating LFY genes from all major lineages of streptophytes. The well-resolved phylogeny unveiled a high-confidence duplication event before the functional divergence of types I and II LFY genes in the ancestry of liverworts, mosses and tracheophytes, supporting sub-functionalization of an ancestral promiscuous gene. The identification of promiscuous genes in Osmunda suggested promiscuous LFY genes experienced an ancient transient duplication. Genomic synteny comparisons demonstrated a deep genomic positional conservation of LFY genes and an ancestral lineage-specific transposition activity in grasses.

LFY转录因子基因家族是一类非常重要的基因家族，能够促进细胞增殖和花发育。对于该基因家族系统演化的研究有利于探索植物演化过程中的花发育。之前的研究在LFY基因家族中鉴定到了一个中间态以及一次基因复制事件，但该基因家族早期的演化轨迹仍不清楚。本文中，作者基于链型植物所有主要支系的LFY基因，通过极大似然法和贝叶斯法重建了LFY基因家族的系统演化。高分辨率的系统发育树揭示了在地钱、苔藓和维管植物的祖先中I类和II类LFY基因功能分化前存在一次复制事件，说明了一个古老混杂基因的亚功能化。在紫萁蕨属植物中鉴定到的混杂基因说明LFY基因经历了一次古老的瞬间复制。基因组共线性比较揭示了LFY基因在基因组位置上的高度保守性，并且禾本科植物中发生过一次谱系特异性的转位事件。

通讯：Jianhua Zhang (http://www.sls.cuhk.edu.hk/index.php/faculty-and-staff/teaching-staff/26-sls/faculty-and-staff/teaching-staff/82-professor-zhang-jianhua)

个人简介：1982年，江苏农业学院，学士；1988年，兰开斯特大学，博士。

研究方向：环境胁迫下的植物生理学和分子生物学。

doi:  https://doi.org/10.1038/s42003-019-0469-4

Journal: Communications Biology

Published date: June 21, 2019