title: Global reprogramming of transcription and metabolism in Medicago truncatula during progressive drought and after rewatering.
abstract: Medicago truncatula is a model legume forage crop native to the arid and semi-arid environments of the Mediterranean. Given its drought-adapted nature, it is an ideal candidate to study the molecular and biochemical mechanisms conferring drought resistance in plants. Medicago plants were subjected to a progressive drought stress over 14 d of water withholding followed by rewatering under controlled environmental conditions. Based on physiological measurements of plant water status and changes in morphology, plants experienced mild, moderate and severe water stress before rehydration. Transcriptome analysis of roots and shoots from control, mildly, moderately and severely stressed, and rewatered plants, identified many thousands of genes that were altered in expression in response to drought. Many genes with expression tightly coupled to the plant water potential (i.e. drought intensity) were identified suggesting an involvement in Medicago drought adaptation responses. Metabolite profiling of drought-stressed plants revealed the presence of 135 polar and 165 non-polar compounds in roots and shoots. Combining Medicago metabolomic data with transcriptomic data yielded insight into the regulation of metabolic pathways operating under drought stress. Among the metabolites detected in drought-stressed Medicago plants, myo-inositol and proline had striking regulatory profiles indicating involvement in Medicago drought tolerance.
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Ji-Yi
authors.initials: JY
authors.lastname: Zhang
authors.forename: Maria H
authors.initials: MH
authors.lastname: Cruz DE Carvalho
authors.forename: Ivone
authors.initials: I
authors.lastname: Torres-Jerez
authors.forename: Yun
authors.initials: Y
authors.lastname: Kang
authors.forename: Stacy N
authors.initials: SN
authors.lastname: Allen
authors.forename: David V
authors.initials: DV
authors.lastname: Huhman
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Tang
authors.forename: Jeremy
authors.initials: J
authors.lastname: Murray
authors.forename: Lloyd W
authors.initials: LW
authors.lastname: Sumner
authors.forename: Michael K
authors.initials: MK
authors.lastname: Udvardi
mesh_terms: D016000:Cluster Analysis; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D017343:Genes, Plant; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D055442:Metabolome / Q000235:genetics; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics; D018520:Plant Shoots / Q000235:genetics; D012984:Software; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D059467:Transcriptome / Q000235:genetics; D014867:Water / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D014157:Transcription Factors; D014867:Water
keywords: ABA; drought stress; gene profiling; legumes; metabolomics; microarray; proline; resistance; tolerance; transcriptomics