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.

Mentor relationships are crucial to retention, success, and wellbeing of women and underrepresented minority scientists in academia. A network of diverse mentors may support achieving long-term career goals, advancement, and retention of both mentors and mentees, thus enhancing diversity, equity, and inclusion initiatives.

Seed dormancy can prevent germination under unfavourable conditions that reduce the chances of seedling survival. Freshly harvested seeds often have strong primary dormancy that depends on the temperature experienced by the maternal plant and which is gradually released through afterripening. However, seeds can be induced into secondary dormancy if they experience conditions or cues of future unfavourable conditions. Whether this secondary dormancy induction is influenced by seed-maturation conditions and primary dormancy has not been explored in depth. In this study, we examined secondary dormancy induction in seeds ofArabidopsis thalianamatured under different temperatures and with different levels of afterripening. We found that low water potential and a range of temperatures, from 8°C to 35°C, induced secondary dormancy. Secondary dormancy induction was affected by the state of primary dormancy of the seeds. Specifically, afterripening had a non-monotonic effect on the ability to be induced into secondary dormancy by stratification; first increasing in sensitivity as afterripening proceeded, then declining in sensitivity after 5 months of afterripening, finally increasing again by 18 months of afterripening. Seed-maturation temperature sometimes had effects that were independent of expressed primary dormancy, such that seeds that had matured at low temperature, but which had comparable germination proportions as seeds matured at warmer temperatures, were more easily induced into secondary dormancy. Because seed-maturation temperature is a cue of when seeds were matured and dispersed, these results suggest that the interaction of seed-maturation temperature, afterripening and post-dispersal conditions all combine to regulate the time of year of seed germination.

Grain sorghum [Sorghum bicolor (L) moench] exhibits intraspecific variability for the rate of dormancy release and pre-harvest sprouting behavior. Two inbred lines with contrasting sprouting response were compared: IS9530 (resistant) and RedlandB2 (susceptible). Precocious dormancy release in RedlandB2 is related to an early loss of embryo sensitivity to ABA and higher levels of gibberellins in imbibed grains as compared with IS9530. With the aim of identifying potential regulatory sites for gibberellin metabolism involved in the expression of dormancy in immature grains of both lines, we carried out a time course analysis of transcript levels of putative gibberellin metabolism genes and hormone content (GA₁, GA₄, GA₈ and GA₃₄). A lower embryonic GA₄ level in dormant IS9530 was related to a sharp and transient induction of two SbGA2-oxidase (inactivation) genes. In contrast, these genes were not induced in less dormant RedlandB2, while expression of two SbGA20-oxidase (synthesis) genes increased together with active GA₄ levels before radicle protrusion. Embryonic levels of GA₄ and its catabolite GA₃₄ correlated negatively. Thus, in addition to the process of gibberellin synthesis, inactivation is also important in regulating GA₄ levels in immature grains. A negative regulation by gibberellins was observed for SbGA20ox2, SbGA2ox1 and SbGA2ox3 and also for SbGID1 encoding a gibberellin receptor. We propose that the coordinated regulation at the transcriptional level of several gibberellin metabolism genes identified in this work affects the balance between gibberellin synthesis and inactivation processes, controlling active GA₄ levels during the expression of dormancy in maturing sorghum grains.