Plant hormones are the intrinsic factors that control plant development. The integration of different phytohormone pathways in a complex network of synergistic, antagonistic and additive interactions has been elucidated in model plants. However, the systemic level of transcriptional responses to hormone crosstalk in Brassica napus is largely unknown. Here, we present an in-depth temporal-resolution study of the transcriptomes of the seven hormones in B. napus seedlings. Differentially expressed gene analysis revealed few common target genes that co-regulated (up- and down-regulated) by seven hormones; instead, different hormones appear to regulate distinct members of protein families. We then constructed the regulatory networks between the seven hormones side by side, which allowed us to identify key genes and transcription factors that regulate the hormone crosstalk in B. napus. Using this dataset, we uncovered a novel crosstalk between gibberellin and cytokinin in which cytokinin homeostasis was mediated by RGA-related CKXs expression. Moreover, the modulation of gibberellin metabolism by the identified key transcription factors was confirmed in B. napus. Furthermore, all data were available online from http://yanglab.hzau.edu.cn/BnTIR/hormone. Our study reveals an integrated hormone crosstalk network in Brassica napus, which also provides a versatile resource for future hormone studies in plant species.

中文翻译：

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比较转录组分析揭示了甘蓝型油菜植物激素网络中多层次的串扰

植物激素是控制植物发育的内在因素。不同植物激素途径在协同、拮抗和加性相互作用的复杂网络中的整合已在模型植物中得到阐明。然而，甘蓝型油菜中激素串扰的转录反应的系统水平在很大程度上尚不清楚。在这里，我们对欧洲油菜幼苗中七种激素的转录组进行了深入的时间分辨率研究。差异表达基因分析揭示了少数共同靶基因受七种激素共同调节（上调和下调）；相反，不同的激素似乎调节蛋白质家族的不同成员。然后，我们并排构建了七种激素之间的调控网络，这使我们能够识别调节甘蓝型油菜中激素串扰的关键基因和转录因子。利用该数据集，我们发现了赤霉素和细胞分裂素之间的一种新的串扰，其中细胞分裂素稳态是由 RGA 相关的CKX表达介导的。此外，在甘蓝型油菜中证实了已确定的关键转录因子对赤霉素代谢的调节。此外，所有数据均可从http://yanglab.hzau.edu.cn/BnTIR/hormone在线获取。我们的研究揭示了甘蓝型油菜中集成的激素串扰网络，这也为未来植物物种激素研究提供了多功能资源。