Inhibition of the light-independent synthesis of chlorophyll in pine cotyledons at low temperature

Cotyledons of Japanese black pine (Pinus thunbergii) were yellow when they developed in darkness at 8 degreesC since the light-Independent synthesis o f chlorophyll was almost completely inhibited in these cotyledons. The leve l of chlorophyll in dark-grown cotyledons was less than one-twentieth of th at in light-grown cotyledons at the same temperature. In the yellow cotyled ons, levels of transcripts of cab, rbcS, rbcL and psbA genes were quite hig h. The large and small subunits of ribulose-1,5-bisphosphate carboxylase/ox ygenase were also detected at relatively high levels in yellow cotyledons. However, the accumulation of the two apoproteins of the light-harvesting ch lorophyll alb-binding protein of PSII was limited because of the limited su pply of chlorophyll.