Function Analysis of Caffeoyl-CoA O-Methyltransferase for Biosynthesis of Lignin and Phenolic Acid in Salvia miltiorrhiza

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• 作者：Zhengjun Wang ; Qian Ge ; Chen Chen ; Xinxin Jin…
• 关键词：Caffeoyl ; CoA O ; methyltransferase ; Cloning and functional analysis ; Lignin biosynthesis ; Phenolic acids ; Salvia miltiorrhiza
• 刊名：Applied Biochemistry and Biotechnology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：181
• 期：2
• 页码：562-572
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Biotechnology; Biochemistry, general;
• 出版者：Springer US
• ISSN：1559-0291
• 卷排序：181

文摘

In this study, we cloned a full-length cDNA and the genomic DNA sequence of SmCCoAOMT (GenBank ID JQ007585) from Salvia miltiorrhiza. The 744-bp open-reading frame encodes a protein of 247 amino acids that shares 95 % similarity with one in Vitis vinifera. Real-time quantitative PCR analysis revealed that SmCCoAOMT is most highly expressed in the stems and can be induced by methyl jasmonate (MeJA) and XC-1 treatment. To evaluate its function in vivo, we generated RNA interference transgenic plants through Agrobacterium tumefaciens-mediated gene transfer. Compared with untransformed control plants, the transgenics had significantly less lignin and the expression of lignin-biosynthetic genes SmCCR and SmCOMT was depressed. In 90-day-old roots from plants of transgenic line M5, accumulations of rosmarinic acid and salvianolic acid B (Sal B) were greatly reduced by 0.89- and 0.69-fold, respectively. This low-Sal B phenotype was stable in the roots, with the level of accumulation being approximately 43.58 mg g−1 dry weight, which was 52 % of the amount measured in the untransformed control. Our results suggest that SmCCoAOMT is involved in lignin biosynthesis and affects the accumulation of phenolic acids. This study also provides potential guidance for using lignin-related genes to genetically engineer Salvia miltiorrhiza.