PCP　and　acpPC　are　the　two　major　antennae　proteins　that　bind　pigments　in　peridinin-containing　dinoflagellates.　The　relationship　between　antennae　proteins　and　cellular　pigments　at　molecular　level　is　still　poorly　understood.　Here　we　identified　and　characterized　the　two　antennae　protein　genes　in　dinoflagellate　Prorocentrum　donghaiense　under　different　light　conditions.　The　mature　PCP　protein　was　32　kDa,　while　acpPC　was　a　polyprotein　each　of　19　kDa.　Both　genes　showed　higher　expression　under　low　light　than　under　high　light,　suggesting　their　possible　role　in　a　low　light　adaptation　mechanism.　The　two　genes　showed　differential　diel　expression　rhythm,　with　PCP　being　more　highly　expressed　in　the　dark　than　in　the　light　period　and　acpPC　the　other　way　around.　HPLC　analysis　of　cellular　pigments　indicated　a　diel　change　of　chlorophyll　c2,　but　invariability　of　other　pigments.　A　stable　peridinin:　chlorophyll　a　pigment　ratio　was　detected　under　different　light　intensities　and　over　the　diel　cycle,　although　the　diadinoxanthin:chlorophyll　a　ratio　increased　significantly　with　light　intensity.　The　results　suggest　that　1)　PCP　and　acpPC　genes　are　functionally　distinct,　2)　PCP　and　acpPC　can　function　under　low　light　as　an　adaptive　mechanism　in　P.　donghaiense,　3).　the　ratios　of　diadinoxanthin:chlorophyll　a　and　peridinin:　chlorophyll　a　can　potentially　be　used　as　an　indicator　of　algal　photophysiological　status　and　a　pigment　signature　respectively　under　different　light　conditions　in　P.　donghaiense.　©　2018