Flowering time is a major determinant of adaptation, fitness and yield in the allopolyploid species rapeseed (Brassica napus). Despite being a close relative to Arabidopsis thaliana, little is known about the timing of floral transition and the genes that govern this process. Winter, semi‐winter and spring type plants have important life history characteristics that differ in vernalization requirements for flowering and are important for growing rapeseed in different regions of the world. In this study, we investigated the timing of vernalization‐driven floral transition in winter rapeseed and the effect of photoperiod and developmental age on flowering time and vernalization responsiveness. Microscopy and whole transcriptome analyses at the shoot apical meristems of plants grown under controlled conditions showed that floral transition is initiated within few weeks of vernalization. Certain Bna.SOC1 and Bna.SPL5 homeologs were among the induced genes, suggesting that they are regulating the timing of cold‐induced floral transition. Moreover, the flowering response of plants with shorter pre‐vernalization period correlated with a delayed expression of Bna.SOC1 and Bna.SPL5 genes. In essence, this study presents a detailed analysis of vernalization‐driven floral transition and the aspects of juvenility and dormancy and their effect on flowering time in rapeseed.

中文翻译：

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春化过程中冬季油菜向花期的过渡

开花时间是油菜（甘蓝型油菜）异多倍体物种的适应性，适应性和产量的主要决定因素。尽管与拟南芥有近亲关系，人们对花卉过渡的时间以及控制该过程的基因知之甚少。冬季，半冬季和春季类型的植物具有重要的生命史特征，其开花的春化要求不同，并且对于世界不同地区的油菜籽生长至关重要。在这项研究中，我们调查了春油菜春化驱动花期的时机，以及光周期和发育年龄对开花时间和春化响应性的影响。在受控条件下生长的植物的茎尖分生组织的显微镜和全转录组分析表明，在春季化的几周内就开始了花的过渡。某些Bna.SOC1和Bna.SPL5同源基因是诱导的基因之一，表明它们正在调节冷诱导的花期过渡的时间。此外，预春化期较短的植物的开花反应与Bna.SOC1和Bna.SPL5基因的表达延迟有关。从本质上讲，这项研究详细分析了由春化作用引起的花期过渡，幼年和休眠的各个方面及其对油菜开花时间的影响。