Abstract：
Secondary dormancy is an adaptive trait that increases reproductive success by aligning seed germination with permissive conditions for seedling establishment. Aethionema arabicum is an annual plant and member of the Brassicaceae that grows in environments characterized by hot and dry summers. Aethionema arabicum seeds may germinate in early spring when seedling establishment is permissible. We demonstrate that long-day light regimes induce secondary dormancy in the seeds of Aethionema arabicum (CYP accession), repressing germination in summer when seedling establishment is riskier. Characterization of mutants screened for defective secondary dormancy demonstrated that RGL2 mediates repression of genes involved in gibberellin (GA) signaling. Exposure to high temperature alleviates secondary dormancy, restoring germination potential. These data are consistent with the hypothesis that long-day-induced secondary dormancy and its alleviation by high temperatures may be part of an adaptive response limiting germination to conditions permissive for seedling establishment in spring and autumn.
摘要：
次生休眠是一种适应性性状，可通过使种子萌发与幼苗建立的允许条件对齐来提高繁殖成功率。Aethionemaarabicum是一年生植物，是十字花科的成员，生长在夏季炎热干燥的环境中。当允许育苗时，阿拉伯Aethionema种子可能在早春发芽。我们证明了长日光照方案会在Aethionemaarabicum（CYP登录号）的种子中诱导次生休眠，在幼苗建立风险较大的夏季抑制发芽。筛选的次生休眠缺陷的突变体的表征表明，RGL2介导与赤霉素（GA）信号传导有关的基因的抑制。暴露于高温可以减轻继发性休眠，恢复发芽潜力。这些数据与以下假设一致：长时间诱导的次生休眠及其高温缓解可能是适应性反应的一部分，将发芽限制在春季和秋季允许幼苗建立的条件下。
