Effects of Light Illumination Variation on Expression of Pigment-rotein Complex in Chroomonas placoidea
An unreported β subunit is found in phycocyanin PC645 of Chroomonas placoidea in our previous works.However,the expression and photo-adaptive function of this subunit under different illumination conditions are un-known.In this study,the changes of pigment composition and expression of PC645 subunits in logarithmic growth cells of C.placoidea cultured under six levels of different light culture conditions are compared.The results show that the increasing of light intensity has no significant effects on Chl a/c-light-harvesting complex,while,facilitates to the accumulation of PC645.Illumination variation particularly affects the relative contents of the two β subunits of PC645 but doesnt affect that of the α subunit.The β2 subunit exhibits the highest relative content at level 112 h and 24 h.Too low or high intensity of light are both not conducive to the expression of β2 subunit.These results suggest that PC645 may play an important role of regulation in light adaptation mechanism of C.placoidea.The ex-isting of subunit β2affects not only the aggregation of cryptophytic phycobiliproteins,but also the adjustability of en-ergy transfer in algal cell.The experimental results will provide a basis for analyzing the function of the new subunit and elucidating the novel photosynthetic system structure and mechanism of cryptophyts.
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维普
