Co-expression clustering across flower development identifies modules for diverse floral forms in Achimenes (Gesneriaceae)

PeerJ

article

Wade R. Roberts¹  Eric H. Roalson¹ 

[1] School of Biological Sciences, Washington State University;Biological Sciences, University of Arkansas

关键词: Flowers;    Co-expression clustering;    Gesneriaceae;    Evolutionary rates;    Pollination syndrome;    RNA-seq;   

DOI  :  10.7717/peerj.8778

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Genetic pathways involved with flower color and shape are thought to play an important role in the development of flowers associated with different pollination syndromes, such as those associated with bee, butterfly, or hummingbird pollination. Because pollination syndromes are complex traits that are orchestrated by multiple genes and pathways, the gene regulatory networks have not been explored. Gene co-expression networks provide a systems level approach to identify important contributors to floral diversification. Methods RNA-sequencing was used to assay gene expression across two stages of flower development (an early bud and an intermediate stage) in 10 species of Achimenes (Gesneriaceae). Two stage-specific co-expression networks were created from 9,503 orthologs and analyzed to identify module hubs and the network periphery. Module association with bee, butterfly, and hummingbird pollination syndromes was tested using phylogenetic mixed models. The relationship between network connectivity and evolutionary rates (dN/dS) was tested using linear models. Results Networks contained 65 and 62 modules that were largely preserved between developmental stages and contained few stage-specific modules. Over a third of the modules in both networks were associated with flower color, shape, and pollination syndrome. Within these modules, several hub nodes were identified that related to the production of anthocyanin and carotenoid pigments and the development of flower shape. Evolutionary rates were decreased in highly connected genes and elevated in peripheral genes. Discussion This study aids in the understanding of the genetic architecture and network properties underlying the development of floral form and provides valuable candidate modules and genes for future studies.

【 授权许可】

CC BY