不同光周期对湛江等鞭金藻生长、岩藻黄素含量和光合作用及相关基因表达的影响  

Effect of Different Photoperiods on Growth,Fucoxanthin Content,Photosynthesis and Related Gene Expression of Isochrysis zhanjiangensis

作　　者：宋奕珩 龚一富[1] 刘博悦 郦露群 王何瑜[2] SONG Yiheng;GONG Yifu;LIU Boyue;LI Luqun;WANG Heyu(School of Marine Science,Ningbo University,Ningbo,Zhejiang 315832;College of Food and Pharmaceutical Sciences,Ningbo University,Ningbo,Zhejiang 315832)

机构地区：[1]宁波大学海洋学院,浙江宁波315832 [2]宁波大学食品与药学学院,浙江宁波315832

出　　处：《核农学报》2024年第3期532-539,共8页Journal of Nuclear Agricultural Sciences

基　　金：宁波市社发重大项目(2017C0510002);宁波大学横向项目(HX2022000115)。

摘　　要：为研究不同光周期对湛江等鞭金藻(Isochrysis zhanjiangensis)细胞生长和岩藻黄素含量的影响,及其光合作用和基因表达调控机理,本研究测定了5种光周期条件下湛江等鞭金藻岩藻黄素、叶绿素含量和叶绿素荧光参数,利用实时荧光定量聚合酶链式反应(RTq-PCR)研究光合作用和岩藻黄素合成关键酶基因表达水平。结果表明,18L∶6D光周期条件下,湛江等鞭金藻细胞生长最快。当光周期为12L∶12D时,湛江等鞭金藻岩藻黄素产量最高,为4.35 mg·L^(-1)。当光周期为6L∶18D时,湛江等鞭金藻单位细胞岩藻黄素含量最高,为0.33 mg·10^(5)cells^(-1),与光周期12L∶12D、18L∶6D和24L∶0D相比分别提高了5.3%、39.1%和63.5%(P<0.01)。光合生理指标结果表明,随着光周期时间的增加,湛江等鞭金藻叶绿素含量及叶绿素荧光参数中PSⅡ实际光合量子产率Y(Ⅱ)和非光化学淬灭系数(qP)呈下降趋势,与岩藻黄素含量的变化趋势一致。RTq-PCR结果表明,随着光周期时间的增加,湛江等鞭金藻Rubisco酶大亚基基因(rbcL)、八氢番茄红素脱氢酶基因(pds)、番茄红素β-环化酶基因(lcyb)和玉米黄素环氧酶基因3(zep3)表达呈下降趋势,与岩藻黄素含量的变化趋势一致,说明光周期可能通过rbcL、pds、lcyb和zep3调控岩藻黄素合成。光周期通过调控光合作用和岩藻黄素生物合成相关基因表达影响湛江等鞭金藻中岩藻黄素的积累。本研究为提高湛江等鞭金藻中的岩藻黄素含量提供了理论依据。In order to study the effect of different photoperiods on cell growth and fucoxanthin content of Isochrysis zhanjiangensis,the regulation mechanism of photosynthesis,gene expression,fucoxanthin,chlorophyll content and chlorophyll fluorescence parameters were measured under 5 different photoperiod conditions.Real-time fluorescence quantitative PCR was used to study the gene expression levels of key enzymes in photosynthesis and fucoxanthin synthesis.As results,the fastest cell growth of I.zhanjiangensis was found at the condition of 18L︰6D photoperiod.The maximum fucoxanthin yield(4.35 mg·L^(-1))was obtained under photoperiod 12L︰12D.Furthermore,the maximum fucoxanthin content(0.33 mg·10^(5) cells^(-1))was obtained under 6L:18D condition,which was 5.3%,39.1%and 63.5%higher than these under the photoperiod of 12L︰12D,18L︰6D and 24L︰0D,respectively.The contents of chlorophyll,PSⅡActual photosynthetic quantum yield[Y(Ⅱ)],and coefficient of photochemical quenching(qP)in chlorophyll fluorescence parameters decreased with the increase of light time in the cycle,which was consistent with the change of fucoxanthin content.This indicated that fucoxanthin synthesis was affected by photosynthesis.The results of RTq-PCR showed that the expression of Rubisco enzyme large subunit gene(rbcL),phytoene desaturase gene(pds),lycopeneβ-cyclase gene(lcyb)and zeaxanthin epoxidase gene 3(zep3)decreased with the increase of photoperiod time,which was consistent with the change of fucoxanthin content.It was suggested that rbcL,pds,lcyb and zep3 may regulate the synthesis of fucoidin in photoperiod.Photoperiod affected the fucoxanthin accumulation of I.zhanjiangensis by regulating the expression of genes related to photosynthesis and fucoxanthin biosynthesis.This study provides a theoretical basis for increasing the content of fucoxanthin in I.zhanjiangensis.

关 键 词：光周期 湛江等鞭金藻 岩藻黄素 光合作用 基因表达 

分 类 号：Q945[生物学—植物学]