title: Two tobacco proline dehydrogenases are differentially regulated and play a role in early plant development.
abstract: Proline dehydrogenase is the rate-limiting enzyme in proline degradation and serves important functions in the stress responses and development of plants. We isolated two tobacco proline dehydrogenases, NtPDH1 and NtPDH2, in the course of screening for genes upregulated in stressed tobacco (Nicotiana tabacum) microspores. Expression analysis revealed that the two genes are differentially regulated. Under unstressed conditions, their steady-state transcript levels were similar in mature pollen and apical meristems, whereas NtPDH2 was expressed predominantly in vegetative organs, styles, and ovules. The expression of NtPDH1 was maintained at a constant low level during 24 h of dehydration, whereas NtPDH2 was upregulated within 1 h after the onset of stress and subsequently downregulated to undetectable levels. Differential and sustained expression was also found for the two enzymatic isoforms of Arabidopsis thaliana AtPDH. Silencing of the NtPDH genes by RNA interference using the CaMV 35S promoter led to increased proline contents, decreased seed set, delayed seed germination and retarded seedling development pointing towards an important function of at least one of the two NtPDH genes during plant reproductive development.
authors.affiliation: Max F. Perutz Laboratories, University Departments at the Vienna Biocenter, Department of Plant Molecular Biology, University of Vienna, Dr. Bohrgasse 9, 1030 Wien, Austria.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ribarits
authors.forename: Alisher
authors.initials: A
authors.lastname: Abdullaev
authors.forename: Alisher
authors.initials: A
authors.lastname: Tashpulatov
authors.forename: Andreas
authors.initials: A
authors.lastname: Richter
authors.forename: Erwin
authors.initials: E
authors.lastname: Heberle-Bors
authors.forename: Alisher
authors.initials: A
authors.lastname: Touraev
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018744:DNA, Plant / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D011394:Proline Oxidase / Q000235:genetics*; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D018749:RNA, Plant; D011394:Proline Oxidase; C452185:proline dehydrogenase (oxidase) 2