Difference of effective component content and key enzyme gene expression of biosynthesis in Atractylodes chinensis with different leaf shapes

Abstract

In this study, four Atractylodes chinensis(A. chinensis) with different leaf shapes, such as the split leaf, long and narrow leaf, oval leaf, and large round leaf, were used as experimental materials to establish a method for simultaneously determining atractylodin, atractylenolide Ⅰ, β-eudesmol, and atractylon in the rhizome of A. chinensis. The expression of key enzyme genes for biosynthesis of acetyl-CoA carboxylase(ACC), 3-hydroxy-3-methylglutaryl-CoA reductase(HMGR), and farnesyl pyrophosphate synthase(FPPS) was detected by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR). High performance liquid chromatography(HPLC) was used to compare the difference in the content of four active components in A. chinensis with different leaf shapes, and the correlation between the content of active components and the expression of key enzyme genes in biosynthesis was discussed. The results show that there was good linearity among atractylodin, atractylenolide Ⅰ, β-eudesmol, and atractylon in the range of 3.30-33.00 μg·mL~(-1)(r =0.999 7), 12.04-120.40 μg·mL~(-1)(r =0.999 5), 29.16-291.60 μg·mL~(-1)(r =0.999 5), and 14.20-142.00 μg·mL~(-1)(r =0.999 5), respectively. The average recoveries were 99.77%(RSD=2.1%), 98.56%(RSD=1.2%), 103.0%(RSD=1.2%), and 100.6%(RSD=1.5%), respectively. The method was accurate and had good reproducibility, which could be used to simultaneously detect atractylodin, atractylenolide Ⅰ, β-eudesmol, and atractylon. The results showed that there were significant differences in the content of four active components in A. chinensis with different leaf shapes. The content of atractylodin, atractylenolide Ⅰ, and β-eudesmol in A. chinensis with split leaves was the highest, which were 1.341 9, 5.237 2, and 12.084 3 mg·g~(-1), respectively. The content of atractylon in A. chinensis with long and narrow leaves was the highest(5.470 1 mg·g~(-1)). The content of atractylodin, atractylenolide Ⅰ, β-eudesmol, and atractylon in A. chinensis with oval leaves was the lowest. The total content of the four effective components in descending order was A. chinensis with split leaves > A. chinensis with long and narrow leaves > A. chinensis with large round leaves > A. chinensis with oval leaves. The gene expression levels of key enzymes ACC, HMGR, and FPPS in A. chinensis with split leaves were the highest(P < 0.05), and the gene expression levels of key enzymes ACC and HMGR in A. chinensis with oval leaves were the lowest(P < 0.05). The gene expression level of key enzyme FPPS in A. chinensis with large round leaves was the lowest. In A. chinensis with different leaf shapes, the key enzyme gene ACC was significantly positively correlated with the polyacetylene component, namely atractylodin(P < 0.01), and the key enzyme genes HMGR and FPPS were positively correlated with the sesquiterpene components, namely atractylenolide Ⅰ, β-eudesmol, and atractylon. In summary, the quality of A. chinensis with split leaves is the best, and the biosynthesis of atractylodin is significantly correlated with the gene expression of key enzyme ACC, which provides a theoretical basis for screening and optimizing the germplasm resources of A. chinensis and improving the quality of medicinal materials.