College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China; Qingdao Key Laboratory of Genetic Development and Breeding in Horticultural Plants, College of Horticulture, Qingdao Agricultural University, 700 Changcheng Road, Qingdao, 266109, China.
College of Horticulture Science and Engineering, State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, Shandong Agricultural University, 61 Daizong Road, Tai'an, 271018, China.
J Plant Physiol. 2021 Feb;257:153353. doi: 10.1016/j.jplph.2020.153353. Epub 2020 Dec 24.
Anthocyanins, a major class of compounds derived from the flavonoid pathway, are important pigments of apple fruit. They can also prevent certain diseases and are beneficial to human health. Fruit pigmentation is a key quality trait that influences consumer preference; therefore, it is of great importance to investigate its regulatory mechanism. Here, we identified a MYB transcription factor (TF), MdMYB114, whose transcript level increased in the skin of the deep red apple fruit. It was determined to belong to the R2R3-MYB TF family and was localized in the nucleus. MdMYB114 overexpression led to anthocyanin accumulation in apple calli. MdMYB114 was not able to form an MBW complex but could enhance anthocyanin biosynthesis and transport by directly binding to the promoters of MdANS, MdUFGT, and MdGST to promote their expression. In addition, multiple assays revealed that MdbZIP4-like, a basic leucine-zipper TF, could directly bind to the MdMYB114 promoter to enhance its expression. Taken collectively, our results provide evidence that MdMYB114 is a positive regulator of anthocyanin biosynthesis and transport and it functions downstream of MdbZIP4-like in apple fruit.
花青苷是类黄酮途径衍生的主要化合物之一，是苹果果实中重要的色素。它们还可以预防某些疾病，对人体健康有益。果实着色是影响消费者喜好的关键品质性状，因此，研究其调控机制非常重要。在这里，我们鉴定了一个 MYB 转录因子（TF），MdMYB114，其转录水平在深红色苹果果实的果皮中增加。它被确定属于 R2R3-MYB TF 家族，并定位于细胞核中。MdMYB114 的过表达导致苹果愈伤组织中花青苷的积累。MdMYB114 不能形成 MBW 复合物，但可以通过直接结合 MdANS、MdUFGT 和 MdGST 的启动子来促进它们的表达，从而增强花青素的生物合成和运输。此外，多项检测表明，碱性亮氨酸拉链 TF MdbZIP4-like 可以直接结合 MdMYB114 启动子以增强其表达。综上所述，我们的研究结果表明 MdMYB114 是花青素生物合成和运输的正调控因子，它在苹果果实中位于 MdbZIP4-like 的下游。
