三角褐指藻岩藻黄素合成途径及其关键基因对高光照的响应

发布时间：2018-08-09 17:11

【摘要】：以三角褐指藻为材料,以岩藻黄素的合成途径中主要的六个酶:八氢番茄红素合成酶、八氢番茄红素脱氢酶、ζ-胡萝卜素脱氢酶、胡萝卜素异构酶、番茄红素β-环化酶和玉米黄素环氧酶为研究对象,研究高光照胁迫对三角褐指藻岩藻黄素合成代谢途径中关键基因表达量以及岩藻黄素含量的变化规律。以光照强度为500μE/(m2·s),分别照射处理三角褐指藻3h、6h、12h,采用HPLC对岩藻黄素含量进行定量分析。随着光照时间的延长,岩藻黄素含量呈现先上升后下降的趋势;高光照6h样品中岩藻黄素含量为1.85mg·g-1DW(dry cell weight),比高光照0h对照组中岩藻黄素含量增加了2.16倍。qRT-PCR分析结果表明玉米黄素环氧酶基因zep1和八氢番茄红素合成酶基因pys转录本在高光照胁迫6h时丰度最高,与对照组相比提高了近2倍,基因表达量的变化表现出与岩藻黄素含量变化相一致的趋势。高光照处理3h后,胡萝卜素异构酶基因crtiso3、八氢番茄红素脱氢酶基因pds、ζ-胡萝卜素脱氢酶基因zds的表达水平相比于对照组明显降低,表现出应对高光照胁迫的快速响应;番茄红素β-环化酶基因lcyb、胡萝卜素异构酶基因crtiso1的表达水平则在高光照处理12h后明显提高;与zep1和pys相比,lcyb和crtiso1基因的表达对高光照胁迫处理的响应时间要滞后至少6h。本研究揭示了高光照胁迫处理下三角褐指藻中岩藻黄素含量及其合成途径中关键基因的表达模式,表明zep1和pys基因表达水平与岩藻黄素合成量之间存在明显的线性关系。
[Abstract]:In this paper, six main enzymes in the biosynthesis pathway of phycoflavin, including lycopene synthase, lycopene dehydrogenase, 味 -carotene dehydrogenase, carotene isomerase, were used as materials. Lycopene 尾 -cyclase and zeaxanthin cyclooxygenase were used to study the effect of high light stress on the expression of key genes and the content of phycoflavin in the biosynthesis pathway of algin triangularis. The content of fucoflavin was quantitatively analyzed by HPLC in the light intensity of 500 渭 E / (m ~ 2 ~ 2 s),) irradiation for 3 h ~ 6 h ~ (12 h) of Phaeophyllum triangularis. With the prolongation of illumination time, the content of alginin increased first and then decreased. The content of alginin in the samples exposed to high light for 6 h was 2.16 times higher than that in the control group at 0 h. The results of qRT-PCR showed that zep1 and pys transcripts of zeaxanthin cyclooxygenase gene and octahydrolycopene synthase gene were increased by 2.16 times. The abundance was the highest at 6h of high light stress. Compared with the control group, the gene expression increased nearly 2 times, and the change of gene expression showed the same trend as the alginin content. The expression levels of carotene isomerase gene crtiso3, octahydrolycopene dehydrogenase gene pdsand 味 -carotene dehydrogenase gene zds were significantly lower than those of the control group after 3 h of high light exposure, showing a rapid response to high light stress. The expression of lycopene 尾 -cyclase gene lcyb and carotene isomerase gene crtiso1 increased significantly after 12 h of high light exposure, and the response time of lcyb and crtiso1 gene expression to high light stress was delayed by at least 6 hours compared with that of zep1 and pys. This study revealed the expression pattern of the key genes in the algin content and biosynthesis pathway of Phaeophyllum triangularis under high light stress, indicating that there was a significant linear relationship between the expression level of zep1 and pys genes and the amount of synthesizing of algin.
【作者单位】：湖北大学生命科学学院;中国农业科学院油料作物研究所农业部油料作物生物学与遗传重点实验室;
【基金】：中国农业科学院科技创新工程项目(CAAS-ASTIP-2013-OCRI)
【分类号】：Q946

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