State Key Laboratory of Agrobiotechnology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Int J Mol Sci. 2022 Jul 26;23(15):8203. doi: 10.3390/ijms23158203.
Anthocyanins accumulate in various organs of rice, and the regulatory genes involved in pigmentation of specific organs, such as pericarp, hull, leaf, apiculus, and stigma have been elucidated. However, the corresponding gene for rice culm pigmentation has not been clarified. The well-known MYB-bHLH-WD40 (MBW) complex plays vital role in regulating the anthocyanin biosynthesis pathway in plants. However, the core members of MBW and the hierarchical regulation between these members are not fully elucidated in rice. Here, by map-based cloning, we identified the culm-specific pigmentation gene whose alleles are also known for hull/pericarp pigmentation. We also clarified that one WD40 protein encoding gene, , is indispensable for anthocyanin biosynthesis in rice. In the cascading regulation among MBW members, (bHLH) acts as the master gene by activating the expression of (MYB), and then C1 activates the expression of (WD40), which is unique in plant species. This enables MBW members to be coordinated in a common way to efficiently regulate anthocyanin biosynthesis genes. Based on these studies, we explored the minimal gene set required for anthocyanin biosynthesis in rice. These findings will help us design new rice varieties with anthocyanin accumulation in specific organs as needed.
花色苷在水稻的各种器官中积累，参与果皮、种皮、叶片、颖壳和柱头等特定器官着色的调控基因已经阐明。然而，水稻茎秆色素沉着的相应基因尚未阐明。众所周知，MYB-bHLH-WD40（MBW）复合物在植物中调控花色苷生物合成途径中起着至关重要的作用。然而，在水稻中，MBW 的核心成员及其成员之间的层次调节尚不完全清楚。在这里，我们通过图谱克隆，鉴定了一个茎特异性色素沉着基因 ，其等位基因也已知与种皮/果皮色素沉着有关。我们还阐明了一个 WD40 蛋白编码基因 ，对于水稻中的花色苷生物合成是必不可少的。在 MBW 成员的级联调控中， （bHLH）作为主基因，通过激活 （MYB）的表达，然后 C1 激活 （WD40）的表达，这在植物物种中是独特的。这使得 MBW 成员能够以共同的方式协调，有效地调控花色苷生物合成基因。基于这些研究，我们探索了水稻中花色苷生物合成所需的最小基因集。这些发现将有助于我们设计具有特定器官中花色苷积累的新型水稻品种。
