title: Oxygen regulation of uricase and sucrose synthase synthesis in soybean callus tissue is exerted at the mRNA level.
abstract: The effect of lowering oxygen concentration on the expression of nodulin genes in soybean callus tissue devoid of the microsymbiont has been examined. Poly(A)+ RNA was isolated from tissue cultivated in 4% oxygen and in normal atmosphere. Quantitative mRNA hybridization experiments using nodule-specific uricase (Nodulin-35) and sucrose synthase (Nodulin-100) cDNA probes confirmed that the synthesis of the uricase and sucrose synthase is controlled by oxygen at the mRNA level. The steady-state levels of uricase and sucrose synthase mRNA increased significantly (5-6- and 4-fold respectively) when the callus tissue was incubated at reduced oxygen concentration. Concomitant with the increase in mRNA level a 6-fold increase in specific activity of sucrose synthase was observed. Two messengers representing poly-ubiquitin precursors also responded to lowering the oxygen concentration. The increase was about 5-fold at 4% oxygen. No expression at atmospheric oxygen or in response to low oxygen was observed when using cDNA probes for other nodulin genes such as leghemoglobin c3, nodulin-22 and nodulin-44.
authors.affiliation: Department of Molecular Biology and Plant Physiology, University of Aarhus, Denmark.
authors.forename: Z T
authors.initials: ZT
authors.lastname: Xue
authors.forename: K
authors.initials: K
authors.lastname: Larsen
authors.forename: B U
authors.initials: BU
authors.lastname: Jochimsen
mesh_terms: D015152:Blotting, Northern; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D005964:Glucosyltransferases / Q000096:biosynthesis*; D008565:Membrane Proteins; D010100:Oxygen / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics; D011061:Poly A / Q000302:isolation & purification; D012333:RNA, Messenger / Q000378:metabolism*; D013025:Glycine max / Q000378:metabolism*; D014503:Urate Oxidase / Q000096:biosynthesis*
chemical_list: D008565:Membrane Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; C045625:nodulin; D011061:Poly A; D014503:Urate Oxidase; D005964:Glucosyltransferases; C022699:sucrose synthase; D010100:Oxygen