Evidence for Dark CO2 Fixation through PEP Carboxylase in Orobanche lucorum A. Br.

Abstract

Summary Evidence is presented for dark CO 2 fixation through PEP carboxylase in Orobanche lucorum on Artemisia absinthium . Young plants were able to fix 14 CO 2 at a rate of 1-2µmoles ° h- 1 ° g- l fresh weight, which was not influenced by light. PEP carboxylase activity was also found and malate and aspartate were identified as the first products of fixation. CO 2 fixation, PEP carboxylase, and respiration were higher during the night. The possible role of this dark CO 2 fixation in Orobanche is discussed.