[Characterization the response of serine/threonine protein kinase mutant to blue light].

In order to investigate the molecular mechanism of silk/threonine protein kinase (STK)-mediated blue light response in the algal , phenotype identification and transcriptome analysis were conducted for . STK mutant strain (with an box reverse insertion in gene coding region) under blue light stress. Phenotypic examination showed that under normal light (white light), there was a slight difference in growth and pigment contents between the wild-type strain CC5325 and the mutant strain . Blue light inhibited the growth and chlorophyll synthesis in cells, but significantly promoted the accumulation of carotenoids in . Transcriptome analysis showed that 860 differential expression genes (DEG) (559 up-regulated and 301 down-regulated) were detected in mutant (STK4) . wild type (WT4) upon treatment under high intensity blue light for 4 days. After being treated under high intensity blue light for 8 days, a total of 1 088 DEGs (468 upregulated and 620 downregulated) were obtained in STK8 . WT8. KEGG enrichment analysis revealed that compared to CC5325, the blue light responsive genes were mainly involved in catalytic activity of intracellular photosynthesis, carbon metabolism, and pigment synthesis. Among them, upregulated genes included , , and , , , , , , and , , , and , as well as genes encoding ATP synthase α, β and c subunits. Downregulated genes included and . The present study uncovered that the protein kinase CrSTK11 of . may participate in the blue light response of algal cells by mediating photosynthesis as well as pigment and carbon metabolism, providing new knowledge for in-depth analysis of the mechanism of light stress resistance in the algae.