College of Life Sciences, Engineering Research Center of the Chinese Ministry of Education for Bioreactor and Pharmaceutical Development, Jilin Agricultural University, Changchun, 130118, China.
Joint Center for Single Cell Biology, Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Funct Integr Genomics. 2023 May 22;23(2):172. doi: 10.1007/s10142-023-01110-3.
The cytochrome P450 superfamily of monooxygenases plays a major role in the evolution and diversification of plant natural products. The function of cytochrome P450s in physiological adaptability, secondary metabolism, and xenobiotic detoxification has been studied extensively in numerous plant species. However, their underlying regulatory mechanism in safflower still remained unclear. In this study, we aimed to elucidate the functional role of a putative CtCYP82G24-encoding gene in safflower, which suggests crucial insights into the regulation of methyl jasmonate-induced flavonoid accumulation in transgenic plants. The results showed that methyl jasmonate (MeJA) was associated with a progressive upregulation of CtCYP82G24 expression in safflower among other treatment conditions including light, dark, and polyethylene glycol (PEG). In addition, transgenic plants overexpressing CtCYP82G24 demonstrated increased expression level of other key flavonoid biosynthetic genes, such as AtDFR, AtANS, and AtFLS, and higher content of flavonoid and anthocyanin accumulation when compared with wild-type and mutant plants. Under exogenous MeJA treatment, the CtCYP82G24 transgenic overexpressed lines showed a significant spike in flavonoid and anthocyanin content compared with wild-type and mutant plants. Moreover, the virus-induced gene silencing (VIGS) assay of CtCYP82G24 in safflower leaves exhibited decreased flavonoid and anthocyanin accumulation and reduced expression of key flavonoid biosynthetic genes, suggesting a possible coordination between transcriptional regulation of CtCYP82G24 and flavonoid accumulation. Together, our findings confirmed the likely role of CtCYP82G24 during MeJA-induced flavonoid accumulation in safflower.
细胞色素 P450 单加氧酶超家族在植物天然产物的进化和多样化中起着重要作用。细胞色素 P450 在生理适应性、次生代谢和外来化合物解毒中的功能已在许多植物物种中得到广泛研究。然而，它们在红花中的潜在调控机制仍不清楚。在这项研究中，我们旨在阐明红花中一个假定的 CtCYP82G24 编码基因的功能作用，这为理解茉莉酸甲酯诱导的黄酮类化合物在转基因植物中积累的调控机制提供了重要线索。结果表明，茉莉酸甲酯（MeJA）与红花中 CtCYP82G24 的表达逐渐上调有关，其他处理条件包括光照、黑暗和聚乙二醇（PEG）。此外，过表达 CtCYP82G24 的转基因植物表现出其他关键类黄酮生物合成基因如 AtDFR、AtANS 和 AtFLS 的表达水平升高，并且与野生型和突变型植物相比，类黄酮和花青素的积累量更高。在外源 MeJA 处理下，CtCYP82G24 转基因过表达系与野生型和突变型植物相比，类黄酮和花青素含量显著增加。此外，红花叶片中 CtCYP82G24 的病毒诱导基因沉默（VIGS）试验表明，类黄酮和花青素的积累减少，关键类黄酮生物合成基因的表达降低，这表明 CtCYP82G24 的转录调控与类黄酮积累之间可能存在协调关系。总之，我们的研究结果证实了 CtCYP82G24 在红花中 MeJA 诱导的类黄酮积累过程中的可能作用。
