Abstract

In order to compare the expression pattern and function of Lhca gene families, theDsLhca genes have been cloned, and two novel genes have been isolated by screening aDunaliella salina cDNA library with a DNA probe coding for the conserved first transmembrane helix of this protein. The number of exons in the different DsLhca genes was slightly conserved. The deduced pre-proteins of the two novel gene had molecular masses of 24.7 and 30.7 kDa, and were assigned into light-harvesting complex of photosystem I (LHCI) Type I and Type III of higher plants in phylogenetic tree, respectively. The DsLhca1 and DsLhca3 responded to the light intensity divergently from DsLhca2. It indicates that changes in the protein composition of LHCI, depending on the growth conditions, will thus result in an adaptation state of the antenna produced to perform better under different environmental conditions.

Key words: Dunaliella salina, Lhca gene family, light-harvesting complex of photosystem I (LHCI), environment stress response.

Abbreviation

Chl, Chlorophyll(s); D. salina, Dunaliella salina; DsLhca, Lhca fromDunaliella salina; DsLhcb, Lhcb from Dunaliella salina; LHC, light-harvesting complex(es); LHCI, light-harvesting complex of PS I; LHCII, light-harvesting complex of PS II; Lhca genes, genes coding for LHCI proteins; Lhcb genes, genes coding for LHC proteins in PSII; PS I, photosystem I ; PS II, photosystem II; HL, high light; LL, low light.