In angiosperms, plants go through different transitions to complete a life cycle. These different transition stages are crucial for plant development. External and internal stimuli affect these transitions, including environmental condition and phytohormones. Auxin is one of the classical phytohormones and crucial to plant morphogenesis establishment and various physiological processes, like phototropism, cell differentiation, cell expansion, floral opening, organ abscission and seed germination. Abscisic acid (ABA) and gibberellic acid (GA) are widely known to work antagonistically in seed germination. Apart from GA and ABA, recent studies have demonstrated that auxin is also involved in the transition from seed dormancy to germination and floral opening. Auxin promotes seed dormancy and inhibits seed germination. Moreover, functions of auxin during floral opening is promising for complementing hormonal crosstalk during this process. In this review, we focus on auxin–ABA crosstalk in regulation of seed germination and dormancy mainly in model plant Arabidopsis thaliana and summarize the knowledge about auxin-mediated flowering in several different species. The systematical knowledge of hormonal signaling provides a guidance for uncovering largely unknown functions of auxin.

中文翻译：

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生长素功能的新见解：植物从种子休眠到发芽和花开放的转变

在被子植物中，植物经历不同的转变以完成一个生命周期。这些不同的过渡阶段对植物发育至关重要。外部和内部刺激会影响这些转变，包括环境条件和植物激素。生长素是经典的植物激素之一，对植物形态发生的建立和各种生理过程至关重要，如向光性、细胞分化、细胞扩张、开花、器官脱落和种子萌发。众所周知，脱落酸 (ABA) 和赤霉酸 (GA) 在种子萌发中具有拮抗作用。除了 GA 和 ABA，最近的研究表明，生长素还参与了从种子休眠到萌发和花开放的过渡。生长素促进种子休眠并抑制种子萌发。而且，花开放期间生长素的功能有望在此过程中补充荷尔蒙串扰。在这篇综述中，我们主要关注模式植物拟南芥中生长素-ABA 串扰在调节种子萌发和休眠中的作用，并总结了几种不同物种中生长素介导开花的知识。激素信号的系统知识为揭示生长素的大部分未知功能提供了指导。