An Arabidopsis ctpA homologue is involved in the repair of photosystem II under high light

A T-DNA insertion mutant AtctpA1 was identified to study the physiological roles of a carboxyl-terminal processing protease (CtpA) homologue in Arabidopsis. Under normal growth conditions, disruption of AtctpA1 did not result in any apparent alterations in growth rate and thylakoid membrane protein components. However the mutant plants exhibited increased sensitivity to high irradiance. Degradation of PSII reaction center protein D1 was accelerated in the mutant during photoinhibition. These results demostrated that AtctpA1 was required for efficient repair of PSII in Arabidopsis under high irradiance. Supported by the Frontier Project of Knowledge Innovation Engineering of the Chinese Academy of Sciences (Grant No. KJCX2-SW-w29)