Expression of genes encoding late nodulins characterized by a putative signal peptide and conserved cysteine residues is reduced in ineffective pea nodules.
Five nodulin genes, PsN1, PsN6, PsN314, PsN335, and PsN466, with reduced expression in ineffective nodules on the pea (Pisum sativum) mutant E135 (sym13) were characterized. They encode small polypeptides containing a putative signal peptide and conserved cysteine residues and show homology to the nodulins PsENOD3/14 and PsNOD6. For each gene, multiple bands were detected by genomic Southern analysis. Northern analysis showed that all five genes were expressed exclusively in nodules and that their temporal expression patterns were similar to that of the leghemoglobin (Lb) gene during nodule development. Their transcripts were localized predominantly from the interzone II-III to the distal part of nitrogen-fixing zone III in effective nodules, resembling the Lb gene. However, transcripts in ineffective E135 nodules were localized in narrower regions than those in the effective nodules. These results indicate that these nodulins are abundant in pea nodules and that their successive expression during nodule development is associated with nitrogen-fixing activity.
Kato
Takashi
T
Department of Life Science, Aichi University of Education, Kariya, Japan.
Kawashima
Kazuya
K
Miwa
Masami
M
Mimura
Yoshifumi
Y
Tamaoki
Masanori
M
Kouchi
Hiroshi
H
Suganuma
Norio
N
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003545:Cysteine; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D018532:Pisum sativum / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D021382:Protein Sorting Signals / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
C489057:ENOD7 protein, Pisum sativum; D008565:Membrane Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; C045625:nodulin; D003545:Cysteine