title: Integrating transcriptomics and metabolomics to characterise the response of Astragalus membranaceus Bge. var. mongolicus (Bge.) to progressive drought stress.
abstract: BACKGROUND
  Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao (A. mongolicus) is an important traditional Chinese herb that is cultivated on a large scale in northwestern China. Understanding plant responses to drought has important effects on ecological environment recovery and local economic development. Here, we combined transcriptomics (Illumina Hiseq 2000) and metabolomics ((1)H-NMR) to investigate how the roots of two-year-old A. mongolicus responded to 14 days of progressive drought stress.
  
  
  RESULTS
  The dried soil reduced the relative water content (RWC) of the leaves and biomass, induced the differential expression of a large fraction of the transcriptome and significantly altered the metabolic processes. PCA analysis demonstrated that the sucrose, proline, and malate metabolites contributed greatly to the separation. Strikingly, proline was increased by almost 60-fold under severe stress compared to the control. Some backbone pathways, including glycolysis, tricarboxylic acid (TCA) cycle, glutamate-mediated proline biosynthesis, aspartate family metabolism and starch and sucrose metabolism, were significantly affected by drought. An integrated analysis of the interaction between key genes and the altered metabolites involved in these pathways was performed.
  
  
  CONCLUSIONS
  Our findings demonstrated that the expression of drought-responsive genes showed a strong stress-dose dependency. Analysis of backbone pathways of the transcriptome and metabolome revealed specific genotypic responses to different levels of drought. The variation in molecular strategies to the drought may play an important role in how A. mongolicus and other legume crops adapt to drought stress.
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. jiaxin198761231@163.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Jia
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. 215210919@qq.com.
authors.forename: Chuangshu
authors.initials: C
authors.lastname: Sun
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. yongchunzuo@163.com.|The Key Laboratory of National Education Ministry for Mammalian Reproductive Biology and Biotechnology, Key Laboratory of Herbivore Reproductive Biotechnology and Breeding Ministry of Agriculture, Inner Mongolia University, Hohhot, 010070, China. yongchunzuo@163.com.
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. 498084982@qq.com.
authors.forename: Guangyue
authors.initials: G
authors.lastname: Li
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. 1198516491@qq.com.
authors.forename: Guobin
authors.initials: G
authors.lastname: Li
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. ndrly@imu.edu.cn.
authors.forename: Liangyu
authors.initials: L
authors.lastname: Ren
authors.affiliation: College of Life Science, The Good Agriculture Practice Engineering Technology Research Center of Chinese and Mongolian Medicine, Inner Mongolia University, Hohhot, 010021, China. guilinchen61@163.com.
authors.forename: Guilin
authors.initials: G
authors.lastname: Chen
mesh_terms: D027885:Astragalus propinquus / Q000235:genetics / Q000502:physiology*; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D055442:Metabolome; D018515:Plant Leaves / Q000502:physiology; D018517:Plant Roots / Q000502:physiology; D013312:Stress, Physiological; D059467:Transcriptome