Photosynthetic carbon fixation in the corollas of Petunia hybrida

David Weiss*, Adiva Shomer‐Ilan, Alexander Vainstein, Abraham H. Halevy

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Corollas of Petunia hybrida (cv. Hit Parade Rosa) flowers fixed 14CO2 under both light and dark conditions. Rates of light fixation were much higher in mature pink corollas than in young, green corollas [57 and 9 nmol (ngchl)1 min‐1], paralleling the development of chloroplasts in these tissues. Stomatal conductance in corollas was only 12% of that in green leaves, mainly due to the presence of few, and non‐functioning stomata in the corolla. The activity and concentration of ribulose bisphosphate carboxylase (EC in corolla extracts were only about 30% (per unit Chi) of those in extracts from green leaves. These results, together with previous results, might indicate a coordinated reduction in activity of systems participating in photosynthesis in corollas. The fixation products following a 6 s pulse with 14CO2, were typical of C, plants in both corollas and green leaves, but a higher level of β‐carboxylation products was found in the corollas. The activity of phosphoenol‐pyruvate carboxylase (EC (per unit protein) was similar in both tissues. Although the total carbon fixed by the corolla constituted only a small part of the metabolites required for flower development, certain photosynthetic metabolites might have a regulatory role in flower development.

Original languageAmerican English
Pages (from-to)345-350
Number of pages6
JournalPhysiologia Plantarum
Issue number3
StatePublished - Mar 1990


  • Carbon fixation
  • corolla. Petunia hybrida. phosphoenolpyruvate carboxylase
  • ribulose‐ 1,5‐bisphosphate carboxylase
  • stomatal conductance


Dive into the research topics of 'Photosynthetic carbon fixation in the corollas of Petunia hybrida'. Together they form a unique fingerprint.

Cite this