IMMUNOCYTOLOCALIZATION OF GLUTAMINE-SYNTHETASE IN MESOPHYLL AND PHLOEM OF LEAVES OF SOLANUM-TUBEROSUM L

• Type: Article in International Scientific Journal
• Date: 1992

Authors

PEREIRA, S (Author) FCUP; CARVALHO, H (Author) REIT; SUNKEL, C (Author) ICBAS; SALEMA, R (Author) FCUP

Journal

Title: Protoplasma

Vol. 167

Pages: 66-73

ISSN: 0033-183X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 51 Citations

Scopus - 52 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-001-Q5T

DOI: 10.1007/bf01353582

Abstract (EN): Localization of glutamine synthetase in Solanum tuberosum leaves was investigated by techniques of Western tissue printing and immunogold electron microscopy. Anti-GS antibodies used in immunolocalization recognize two peptides (45 kDa and 42 kDa) on Western blots. Antibody stained tissue prints on nitrocellulose membranes allowed low resolution localization of GS. Immunostaining was most evident in the adaxial phloem of the leaf midribs and petiole veins. High-resolution localization of glutamine synthetase by immunogold electron microscopy revealed that this enzyme occurs in both the chloroplasts and the cytosol of S. tuberosum leaf cells. However, GS was specifically associated with the chloroplasts of mesophyll cells and with the cytoplasm of phloem companion cells. The evidence for cell-specific localization of chloroplast and cytosolic GS presented here agrees with the recently reported cell-specific pattern of expression of GUS reporter gene, directed by promoters for chloroplast and cytosolic GS form in tobacco transgenic plants. These data provide additional clues to the interpretation of the functional role of these different isoenzymes and its relationship with their specific localization.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8