The results show that the activities of ribulose-1,5-bisphosphate carboxylase (Rubisco) and nitrate reductase (NR) increase significantly on the first day under high (HL) and medium (ML) light intensities, and fall drastically after two days.
Consequently,the algal cells absorbed nitrate quickly for heterotrophic growth,leading to ultimately short supply of nitrogen,which in turn inhibited the formation of chlorophyll and the activity of ribulose-1,5-bisphosphate carboxylase (Rubisco).
Afull-length cDNA encoding the small subunit (rbcS) of ribulose-1 ,5-bisphosphatecarboxylase/ oxygenase (RuBisCO)fromDunaliellasalina,one of the most halotolerant unicellu-lar eukaryotic alga , was cloned by the method of reverse transcription polymerase chain reaction(RT-PCR) .