Abstract:

Two genes encoding phytoene dehydrogenase（PDS）BaPDS1 and BaPDS2 were cloned by
RT-PCR from white flower Chinese kale（Brassica alboglabra Bailey）. They were deposited in GenBank
with accession number KX426039 and KX426040 respectively. BaPDS1 and BaPDS2 each contained an
open reading frame of 1 692 bp or 1 698 bp in length，encoding 563 and 565 amino acids，respectively.
Phylogeny derived from the retrieved relative homologous counterparts of other species demonstrated that
the PDS proteins are relatively conserved in plant evolution. A closest phylogenetic relationship of PDS
genes was found among Chinese kale，cabbage，Chinese cabbage，and cauliflower. Semi quantitative
RT-PCR analysis showed that the expression of PDS genes differ significantly at both temporal and spatial
levels. The relative expression levels of BaPDSs were lower in germinating seeds，and then sharply
induced thereafter. BaPDS1 was constitutively expressed in different organs of mature stage，while
BaPDS2 abundance was obviously different among organs at the same developmental stage. Particularly，no BaPDS2 was detected in young seeds. The transcription levels of BaPDSs were significantly lower in
sepals than in other flower tissues. BaPDS1 was accumulated in stamens and pistils during blooming.

Key words: Brassica alboglabra, phytoene dehydrogenase（PDS）, cloning, expression, carotenoids