Pleiotropy in developmental regulation by flowering‐pathway genes: is it an evolutionary constraint?

Abstract

Summary Pleiotropy occurs when one gene influences more than one trait, contributing to genetic correlations among traits. Consequently, it is considered a constraint on the evolution of adaptive phenotypes because of potential antagonistic selection on correlated traits, or, alternatively, preservation of functional trait combinations. Such evolutionary constraints may be mitigated by the evolution of different functions of pleiotropic genes in their regulation of different traits. Arabidopsis thaliana flowering‐time genes, and the pathways in which they operate, are among the most thoroughly studied regarding molecular functions, phenotypic effects, and adaptive significance. Many of them show strong pleiotropic effects. Here, we review examples of pleiotropy of flowering‐time genes and highlight those that also influence seed germination. Some genes appear to operate in the same genetic pathways when regulating both traits, whereas others show diversity of function in their regulation, either interacting with the same genetic partners but in different ways or potentially interacting with different partners. We discuss how functional diversification of pleiotropic genes in the regulation of different traits across the life cycle may mitigate evolutionary constraints of pleiotropy, permitting traits to respond more independently to environmental cues, and how it may even contribute to the evolutionary divergence of gene function across taxa.

Gene co-expression analysis of tomato seed maturation reveals tissue-specific regulatory networks and hubs associated with the acquisition of desiccation tolerance and seed vigour

“…In this study, a number of genes were found whose expression was highly correlated with both seed traits, being putative candidate genes that could have a pleiotropic function governing both dormancy and longevity. In the ME2 module, the presence of genes controlling owering concurs with the concept of environmentally controlled pleiotropic role of owering in dormancy [76]. Also we found DORMANCY MAKER 1 (DRM1, Solyc03g006360.3.1), a auxin-regulated gene used as a marker of bud dormancy but not in Arabidopsis seed [77].…”

Functional variants of DOG1 control seed chilling responses and variation in seasonal life-history strategies in Arabidopsis thaliana

“…S11 and S12 and Tables S6 B and C). Pleiotropic effects of DOG1 on flowering and germination mediated by miR156 and miR172 may be a mechanism behind these trait correlations (60,76).…”

HD-ZIP I Transcription Factor (PtHB13) Negatively Regulates Citrus Flowering through Binding to FLOWERING LOCUS C Promoter

“…FLC is a typical MADS-box gene that acts as a central repressor of floral transition in Arabidopsis [22]. In recent years, many of the components and environmental factors that influence the chromatin state of FLC, whether active or inactive, have been reported in model plants [18,19,31]. However, it is unknown which transcription factor drives the transcription of FLC.…”

“…In Arabidopsis, FLC is involved in the vernalization induction of flowering [17,18]. Without exposure to low temperature, FLC represses flowering by repressing flowering activators such as SOC1 and FT [18,19]. In perennial herbaceous plants, PERPETUAL FLOWERING1 (FLC homolog) is transiently repressed by low temperature to allow Arabis alpina to flower in the subsequent season, but then undergoes upregulation by warm temperature to limit flowering to only the spring season [20].…”