Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China (OUC), Qingdao 266003, Shandong, China.
Int J Mol Sci. 2018 Jan 7;19(1):175. doi: 10.3390/ijms19010175.
is a commercial microalga, that produces abundant levels of astaxanthin under stress conditions. Acetate and Fe are reported to be important for astaxanthin accumulation in . In order to study the synergistic effects of high light stress and these two factors, we obtained transcriptomes for four groups: high light irradiation (HL), addition of 25 mM acetate under high light (HA), addition of 20 μM Fe under high light (HF) and normal green growing cells (HG). Among the total clean reads of the four groups, 156,992 unigenes were found, of which 48.88% were annotated in at least one database (Nr, Nt, Pfam, KOG/COG, SwissProt, KEGG, GO). The statistics for DEGs (differentially expressed genes) showed that there were more than 10 thousand DEGs caused by high light and 1800-1900 DEGs caused by acetate or Fe. The results of DEG analysis by GO and KEGG enrichments showed that, under the high light condition, the expression of genes related to many pathways had changed, such as the pathway for carotenoid biosynthesis, fatty acid elongation, photosynthesis-antenna proteins, carbon fixation in photosynthetic organisms and so on. Addition of acetate under high light significantly promoted the expression of key genes related to the pathways for carotenoid biosynthesis and fatty acid elongation. Furthermore, acetate could obviously inhibit the expression of genes related to the pathway for photosynthesis-antenna proteins. For addition of Fe, the genes related to photosynthesis-antenna proteins were promoted significantly and there was no obvious change in the gene expressions related to carotenoid and fatty acid synthesis.
雨生红球藻是一种商业微藻，在应激条件下会产生丰富水平的虾青素。据报道，乙酸盐和铁对于雨生红球藻中虾青素的积累很重要。为了研究高光胁迫和这两个因素的协同作用，我们获得了四个组的转录组：高光照射（HL）、高光下添加 25mM 乙酸盐（HA）、高光下添加 20μM 铁（HF）和正常绿色生长细胞（HG）。在这四个组的总清洁读取中，发现了 156992 个 unigenes，其中 48.88%在至少一个数据库（Nr、Nt、Pfam、KOG/COG、SwissProt、KEGG、GO）中被注释。差异表达基因（DEGs）的统计显示，高光引起的 DEGs 超过 10000 个，乙酸盐或铁引起的 DEGs 为 1800-1900 个。GO 和 KEGG 富集的 DEG 分析结果表明，在高光条件下，与许多途径相关的基因表达发生了变化，如类胡萝卜素生物合成途径、脂肪酸延长途径、光合作用天线蛋白途径、光合生物碳固定途径等。高光下添加乙酸盐显著促进了与类胡萝卜素生物合成和脂肪酸延长途径相关的关键基因的表达。此外，乙酸盐可以明显抑制与光合作用天线蛋白途径相关的基因表达。对于铁的添加，与光合作用天线蛋白相关的基因明显被促进，而与类胡萝卜素和脂肪酸合成相关的基因表达没有明显变化。
