Abstract
We observed severe injury in the leaves of rice seedlings (Akitakomachi) after a few days chilling only when the roots were not chilled (L/H), preceded by the blocking of photosynthetic electron transport from PSII to PSI, whereas no such injury was observed when the whole seedlings were chilled (L/L) (Suzuki et al. 2008). It was, however, unclear if the blocking was the primary cause of the injury, because the photosynthesis was analyzed at 25 degrees C after chilling. In this paper, we analyzed photosynthesis at 9 degrees C during chilling treatments. Under L/L, ETR at PSI was as high as that of non-chilled seedlings. Under L/H, quite low ETR at both PSII and PSI, an over-reduction at PSII, and an over-oxidation at PSI during the short-term photosynthesis were observed. No significant difference was observed between L/L and L/H, in the linear electron transport in the thylakoid preparations.
