Carotenoids are widely distributed and structurally diverse, which have significant roles in the photosynthesis of plants. As a precursor of vitamin A, carotenoids are also antioxidants that reduce various chronic diseases, which are beneficial for human health. Currently, the existing studies concerned the biological roles of APETALA2 (AP2)/ethylene-responsive factor (ERF) genes originated from higher plants. The AP2 superfamily of the transcriptional regulator was identified in higher plants, which was related to growth, development, carotenoid metabolism, and responses to various stresses. However, the regulatory mechanisms of the AP2-modulating carotenoid metabolism have not been reported in microalgae, which remain to be elucidated. Dunaliella parva AP2 (i.e., DpAP2), an important transcription factor, promotes carotenoid accumulation by binding to the promoter of target gene. Here, we identified an important AP2/ERF transcription factor, DpAP2, which could promote carotenoid accumulation by binding to the promoter of target gene. To demonstrate the function of DpAP2, the interacting proteins were identified by the yeast two-hybrid system. The results showed that DpAP2 could interact with three proteins with different activities (DNA-binding transcription factor activity, protein kinase activity, and alpha-D-phosphohexomutase activity); these proteins may be associated with multiple biological processes. This paper laid a good foundation for a deep understanding of the regulatory mechanisms of DpAP2 and genetic engineering breeding in D. parva.

类胡萝卜素分布广泛，结构多样，在植物的光合作用中发挥着重要作用。作为维生素A的前体，类胡萝卜素也是减少各种慢性疾病的抗氧化剂，有益于人体健康。目前，现有的研究关注的是APETALA2 (AP2)/乙烯反应因子 (ERF)基因来源于高等植物。AP2转录调节子超家族在高等植物中被发现，与生长、发育、类胡萝卜素代谢和对各种胁迫的反应有关。然而，尚未在微藻中报道AP2调节类胡萝卜素代谢的调节机制，这仍有待阐明。小杜氏藻AP2（即DpAP2）是一种重要的转录因子，通过与靶基因的启动子结合来促进类胡萝卜素的积累。在这里，我们鉴定了一个重要的 AP2/ERF 转录因子 DpAP2，它可以通过与靶基因的启动子结合来促进类胡萝卜素的积累。为了证明 DpAP2 的功能，酵母双杂交系统鉴定了相互作用的蛋白质。结果表明，DpAP2可以与三种具有不同活性（DNA结合转录因子活性、蛋白激酶活性和α-D-磷酸六变位酶活性）的蛋白质相互作用；这些蛋白质可能与多种生物过程有关。该论文为深入了解DpAP2的调控机制和基因工程育种奠定了良好的基础。D. parva.