Song Zhaopeng, Luo Yong, Wang Weifeng, Fan Ningbo, Wang Daibin, Yang Chao, Jia Hongfang
College of Tobacco Science, Henan Agricultural University, Zhengzhou, China.
Guangxi Branch of China National Tobacco Corporation, Nanning, China.
Front Plant Sci. 2020 Jan 24;10:1683. doi: 10.3389/fpls.2019.01683. eCollection 2019.
Phosphorus (P) is an essential macronutrient for plant growth and development. The concentration of flavonol, a natural plant antioxidant, is closely related to phosphorus nutritional status. However, the regulatory networks of flavonol biosynthesis under low Pi stress are still unclear. In this study, we identified a PFG-type MYB gene, , whose expression was significantly up-regulated under low Pi conditions. Overexpression of dramatically increased flavonol concentration and the expression of certain flavonol biosynthetic genes (, , and ) in transgenic tobacco. Moreover, overexpression of also increased the total P concentration and enhanced tobacco tolerance of low Pi stress by increasing the expression of -family genes ( and ). We further demonstrated that overexpressing plants and overexpressing plants also had increased flavonol and P accumulation and higher tolerance to low Pi stress, showing a similar phenotype to -overexpressing transgenic tobacco under low Pi stress. These results suggested that tobacco acts as a phosphorus starvation response enhancement factor and regulates and expression, which results in increased flavonol and P accumulation and enhances tolerance to low Pi stress.
磷（P）是植物生长发育所必需的大量元素。黄酮醇是一种天然植物抗氧化剂，其浓度与磷营养状况密切相关。然而，低磷胁迫下黄酮醇生物合成的调控网络仍不清楚。在本研究中，我们鉴定了一个PFG型MYB基因，其在低磷条件下表达显著上调。在转基因烟草中，该基因的过表达显著增加了黄酮醇浓度以及某些黄酮醇生物合成基因（、和）的表达。此外，该基因的过表达还通过增加家族基因（和）的表达提高了总磷浓度并增强了烟草对低磷胁迫的耐受性。我们进一步证明，过表达植株和过表达植株也具有增加的黄酮醇和磷积累以及对低磷胁迫的更高耐受性，在低磷胁迫下表现出与过表达转基因烟草相似的表型。这些结果表明，烟草作为一个磷饥饿响应增强因子，调节和表达，导致黄酮醇和磷积累增加，并增强对低磷胁迫的耐受性。
