SmGRAS1 and SmGRAS2 Regulate the Biosynthesis of Tanshinones and Phenolic Acids in Salvia miltiorrhiza
SmGRAS1 and SmGRAS2 Regulate the Biosynthesis of Tanshinones and Phenolic Acids in Salvia miltiorrhiza
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DOI：
10.3389/fpls.2019.01367
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发表时间：
2019-10-30
影响因子：
5.6
通讯作者：
Liang, Zongsuo
中科院分区：
文献类型：
--
作者：
Li, Wenrui;Bai, Zhenqing;Liang, Zongsuo
丹参因其在治疗心脏病方面的优异性能而被广泛使用。丹参酮和酚酸类化合物是两类重要的有效代谢产物，其生物合成已引起人们的广泛关注。本研究中，我们对S.丹参。SmGRAS 1/2在丹参根周高表达，丹参酮主要在根周积累。丹参。SmGRAS 1/2的过表达上调丹参酮的积累，下调GA，酚酸含量和根生物量。SmGRAS 1/2反义表达降低了丹参酮的积累，增加了GA、酚酸含量和根生物量。生物合成基因的表达模式与化合物积累的变化相一致。GA处理增加丹参酮，酚酸，GA含量在过表达线，并恢复根生长抑制过表达SmGRAS 1/2。随后，酵母单杂交，双荧光素酶，和电泳迁移率变动分析（EMSA）显示SmGRAS 1促进丹参酮的生物合成，直接结合到GARE基序的SmKSL 1启动子和激活其表达。酵母双杂交实验表明SmGRAS 1与SmGRAS 2具有物理相互作用。综上所述，SmGRAS 1/2在丹参根的生长和酚酸类物质的合成中起抑制作用，而在丹参酮类物质的合成中起正调节作用。总体而言，我们的研究结果揭示了SmGRAS 1/2在次生代谢基因工程改变中的潜在价值。
Salvia miltiorrhiza is one of the most widely used traditional Chinese medicinal plants because of its excellent performance in treating heart diseases. Tanshinones and phenolic acids are two important classes of effective metabolites, and their biosynthesis has attracted widespread interest. Here, we functionally characterized SmGRAS1 and SmGRAS2, two GRAS family transcription factors from S. miltiorrhiza. SmGRAS1/2 were highly expressed in the root periderm, where tanshinones mainly accumulated in S. miltiorrhiza. Overexpression of SmGRAS1/2 upregulated tanshinones accumulation and downregulated GA, phenolic acids contents, and root biomass. However, antisense expression of SmGRAS1/2 reduced the tanshinones accumulation and increased the GA, phenolic acids contents, and root biomass. The expression patterns of biosynthesis genes were consistent with the changes in compounds accumulation. GA treatment increased tanshinones, phenolic acids, and GA contents in the overexpression lines, and restored the root growth inhibited by overexpressing SmGRAS1/2. Subsequently, yeast one-hybrid, dual-luciferase, and electrophoretic mobility shift assays (EMSA) showed SmGRAS1 promoted tanshinones biosynthesis by directly binding to the GARE motif in the SmKSL1 promoter and activating its expression. Yeast two-hybrid assays showed SmGRAS1 interacted physically with SmGRAS2. Taken together, the results revealed that SmGRAS1/2 acted as repressors in root growth and phenolic acids biosynthesis but as positive regulators in tanshinones biosynthesis. Overall, our findings revealed the potential value of SmGRAS1/2 in genetically engineering changes in secondary metabolism.