title: Accumulation of astragalosides and related gene expression in different organs of Astragalus membranaceus Bge. var mongholicus (Bge.).
abstract: Astragalus membranaceus is one of the most important traditional Korean and Chinese medicinal herbs because it contains triterpenoid saponins (astragaloside I, II, III, and IV), which have beneficial and pharmacological effects on health. In this study, we analyzed 10 mevalonate pathway genes that are involved in astragaloside biosynthesis using the Illumina/Solexa HiSeq2000 platform. We determined the expression levels of the 10 genes using quantitative real-time PCR, and analyzed the accumulation of astragalosides in different organs using high-performance liquid chromatography. Genes related to the mevalonate pathway were expressed in different levels in different organs. Almost all genes showed high transcript levels in the stem and leaf, with the lowest transcript levels being recorded in the root. In contrast, most astragalosides accumulated in the root. In particular, the astragaloside IV content was distributed in the following order: root (0.58 mg/g DW) > flower (0.27 mg/g DW) > stem (0.23 mg/g DW) > leaf (0.04 mg/g DW). In the root, astragaloside II exhibited the highest content (2.09 mg/g DW) compared to astragaloside I, III, and IV. Notably, gene expression did not follow the same pattern as astragaloside accumulation. We suggest carefully that astragalosides are synthesized in the leaves and stem and then translocated to the root. This study contributes towards improving our understanding of astragaloside biosynthesis in A. membranaceus.
authors: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. yeonbokkim@hanmail.net.
authors: Yeon Bok
authors: YB
authors: Kim
authors: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. thwe.ayeaye@gmail.com.
authors: Aye Aye
authors: AA
authors: Thwe
authors: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. Lixiaohua2007@hotmail.com.
authors: Xiaohua
authors: X
authors: Li
authors: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. tuan_pham_6885@yahoo.com.
authors: Pham Anh
authors: PA
authors: Tuan
authors: Department of Integrative Plant Science, Chung-Ang University, Anseong 456-756, Korea. slee@cau.ac.kr.
authors: Sanghyun
authors: S
authors: Lee
authors: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. ljw5407@yahoo.co.kr.
authors: Jong Won
authors: JW
authors: Lee
authors: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia. mvalanarasu@gmail.com.
authors: Mariadhas Valan
authors: MV
authors: Arasu
authors: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia. naldhabi@ksu.edu.sa.
authors: Naif Abdullah
authors: NA
authors: Al-Dhabi
authors: Department of Crop Science, Chungnam National University, 99 Daehak-Ro, Yuseong-gu, Daejeon 305-764, Korea. supark@cnu.ac.kr.
authors: Sang Un
authors: SU
authors: Park
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D027885:Astragalus propinquus / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D053898:Biosynthetic Pathways; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016366:Open Reading Frames; D009928:Organ Specificity / Q000235:genetics; D012503:Saponins / Q000737:chemistry / Q000378:metabolism*; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism
chemical_list: D012503:Saponins; D013729:Terpenes