Effects of cytokinins on the polypeptide composition of microsomal membranes from Catharanthus roseus cell suspension cultures

Citation
K. Chahed et al., Effects of cytokinins on the polypeptide composition of microsomal membranes from Catharanthus roseus cell suspension cultures, ACT BOT GAL, 146(4), 1999, pp. 375-386
Citations number
35
Categorie Soggetti
Plant Sciences
Journal title
ACTA BOTANICA GALLICA
ISSN journal
12538078 → ACNP
Volume
146
Issue
4
Year of publication
1999
Pages
375 - 386
Database
ISI
SICI code
1253-8078(1999)146:4<375:EOCOTP>2.0.ZU;2-1
Abstract
The effects of benzylaminopurine (BAP) on the polypeptide pattern of membra nes from Catharanthus roseus cells were investigated using two-dimensional gel electrophoresis. In order to characterize the membrane preparation micr osomes, issued from cells grown in different hormonal conditions (+2,4-D, - 2,4-D, BAP), microsomes were harvested at different times of cell culture a nd tested for their ATPases prior to 2-D PAGE analysis. Inhibitory studies revealed that the total ATPase activity within these membranes was slightly affected by sodium azide and nitrate (less than 5%) indicating that mitoch ondrial and tonoplat vesicles were little represented in the crude fraction s. Membranes contained, however, ATPases that were totally dependent on mag nesium and strongly inhibited by orthovanadate (90% inhibition). Analysis b y 2-D PAGE of the protein composition of these membranes revealed that the overall pattern was conserved after cytokinin treatment. A few polypeptides appeared, however, to be regulated by BAP. Particularly, the accumulation of a polypeptide with an apparent molecular mass of 33 kDa (P33) was increa sed markedly after cytokinin treatment. This stimulation was slightly inhib ited by 2,4-D, a known inhibitor of alkaloid accumulation. Time course stud ies indicated that the effect of cytokinin on the accumulation of polypepti de P33 starts within 24 hours of cytokinin treatment and persists for at le ast 96 hours.