Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing 100193, China.
Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics & Cytology, Northeast Normal University, Changchun 130024, China.
Plant Sci. 2022 Sep;322:111290. doi: 10.1016/j.plantsci.2022.111290. Epub 2022 Apr 20.
The carotenoids biosynthesis pathway in plants has been studied extensively, yet little is known about the regulatory mechanisms underlying this process, especially for ornamental horticulture plants. In this study, a natural variation of chrysanthemum with orange coloration was identified and compared with the wild type with pink coloration; the content and component of carotenoids were largely enriched in the mutant with orange coloration. CmCCD4a-5, the DNA sequence in both 'Pink yan' and the mutant, was identified and shown to function as a carotenoid degradation enzyme. Compared with 'Pink yan', the mutant shows lower expression level of CmCCD4a-5. Furthermore, CmGATA4 was found to have an opposite expression trend to CmCCD4a-5, and it could directly bind with the CmCCD4a-5 promoter. Taken together, this study demonstrates that CmGATA4 acts as a negative regulator of CmCCD4a-5 and, furthermore, low expression of CmCCD4a-5 resulted in carotenoid accumulation in the mutant.
植物类胡萝卜素生物合成途径已经得到了广泛的研究，但对于这一过程的调控机制知之甚少，特别是对于观赏园艺植物。本研究鉴定了一种具有橙色颜色的菊花自然变异体，并与粉红色野生型进行比较；橙色变异体的类胡萝卜素含量和成分大大丰富。鉴定并证明 CmCCD4a-5 的 DNA 序列在“Pink yan”和突变体中都起作用，作为一种类胡萝卜素降解酶。与“Pink yan”相比，突变体显示出较低水平的 CmCCD4a-5 表达。此外，发现 CmGATA4 的表达趋势与 CmCCD4a-5 相反，并且可以直接与 CmCCD4a-5 启动子结合。综上所述，本研究表明 CmGATA4 作为 CmCCD4a-5 的负调节剂起作用，并且 CmCCD4a-5 的低表达导致突变体中类胡萝卜素的积累。
