Department of Biology, Duke University, Box 90338, Durham, NC, 27708, USA.
New Phytol. 2017 Oct;216(2):388-400. doi: 10.1111/nph.14520. Epub 2017 Mar 22.
Different life stages frequently respond to the same environmental cue to regulate development so that each life stage is matched to its appropriate season. We investigated how independently each life stage can respond to shared environmental cues, focusing on vernalization, in Arabidopsis thaliana plants. We first tested whether effects of rosette vernalization persisted to influence seed germination. To test whether genes in the vernalization flowering pathway also influence germination, we assessed germination of functional and nonfunctional alleles of these genes and measured their level of expression at different life stages in response to rosette vernalization. Rosette vernalization increased seed germination in diverse ecotypes. Genes in the vernalization flowering pathway also influenced seed germination. In the Columbia accession, functional alleles of most of these genes opposed the germination response observed in the ecotypes. Some genes influenced germination in a manner consistent with their known effects on FLOWERING LOCUS C gene regulation during the transition to flowering. Others did not, suggesting functional divergence across life stages. Despite persistent effects of environmental conditions across life stages, and despite pleiotropy of genes that affect both flowering and germination, the function of these genes can differ across life stages, potentially mitigating pleiotropic constraints and enabling independent environmental regulation of different life stages.
不同的生命阶段经常对相同的环境线索做出反应,以调节发育,从而使每个生命阶段都适应其适当的季节。我们研究了每个生命阶段如何独立地对共同的环境线索做出反应,重点是拟南芥中的春化作用。我们首先测试了头状花序春化作用的影响是否持续到影响种子萌发。为了测试春化开花途径中的基因是否也影响萌发,我们评估了这些基因的功能和非功能等位基因的萌发,并测量了它们在不同生命阶段对头状花序春化作用的表达水平。头状花序春化作用增加了不同生态型的种子萌发。春化开花途径中的基因也影响种子萌发。在哥伦比亚品种中,这些基因的大多数功能等位基因与在生态型中观察到的萌发反应相反。一些基因的萌发方式与其在向开花过渡过程中对 FLOWERING LOCUS C 基因调控的已知作用一致。其他基因则不然,这表明不同生命阶段的功能分化。尽管环境条件在不同生命阶段都有持续的影响,而且影响开花和萌发的基因也有重叠,但这些基因在不同生命阶段的功能可能不同,这可能减轻了多效性的限制,并使不同生命阶段能够独立地对环境进行调节。