Arabidopsis thaliana photorespiratory mutants show a slower electron transfer at the photosystem II acceptor-side.

In Arabidopsis thaliana photorespiratory mutants, PSII electron transfer is slowed at the acceptor side during ambient CO2, especially in amiRgox1gox2.

• Why it matters: Photorespiration may regulate primary photosynthetic electron flow, but whether other photorespiratory mutants alter PSII acceptor-side properties beyond hrp1-1 is unclear.
• What they did: Chlorophyll fluorescence decay kinetics were measured in pglp1-1, plgg1-1, and amiRgox1gox2 grown at high 10,000 ppm CO2, then shifted to ambient CO2, including ambient CO2 plus high light.
• The result: Decay kinetics were similar under high 10,000 ppm CO2, slowed in amiRgox1gox2 after high-to-ambient CO2 transfer, unchanged in pglp1-1, and altered in plgg1-1 only under ambient CO2 with high light.