Moderate photoinhibition of PSII and oxidation of P700 contribute to chilling tolerance of tropical tree species in subtropics of China

In the subtropics, a few tropical tree species are distributed and planted for ornamental horticultural purposes; however, photosynthesis of these can be impaired by chilling. This study aimed to understand how respond Light-dependent CO2 assimilation reactions six from geographically diverse areas, but grown at lower subtropical site in China, were monitored during chilling (≤ 10°C). Chilling induced stomatal nonstomatal effects moderate photoinhibition PSII, with severe effect Ixora chinensis. Woodfordia fruticosa was little affected chilling, negligible reduction PSII activity, higher cyclic electron flow (CEF), oxidation state P700 (P700+). Photoinhibition thus reduced P700, while active CEF oxidative damage PSI maintained Studied parameters revealed that coupling between light-dependent enhanced under