Screening of A/Ci-mutant in Arabidopsis thaliana for identifying regulatory elements of the limiting factors in photosynthesis.

Abstract

Objective of our research is to enhance the ability of CO₂-fixation of plants by improving their photosynthetic performance. In C3-plants, CO₂-fixation rate at low CO₂ is limited by factors relating to Rubisco-carboxylase reaction, at high CO₂ by factors relating to RuBP-regeneration. In this work, for the identification of regulatory elements of CO₂-fixation in plants we try a screening of Arabidopsis mutants that show abnormalities in photosynthesis at low or high CO₂. In the screening of mutants we adopted a quantum yield of PSII (Φ(PSII)) as an index of photosynthesis rate for a high through put analysis. Now, we have three mutants which showed low Φ(PSII) with independence of CO₂, compared to wild type (2 mutants); high Φ(PSII) at low CO₂, compared to wild type (1 mutant). We identified that these mutations were located in the chromosome 1, 3, and 4, respectively.