温度胁迫及恢复初期稀杯盔形珊瑚共生虫黄藻Hsp70、Hsp90、psaA、psbA基因表达分析  

Heat-induced stress genes Hsp70,Hsp90 and chloroplast psa A and psb A gene expressions of Galaxea astreata endosymbiotic zooxanthella revealing the ability of tolerance and recovery

作　　者：沈城[1,2] 刘楚吾[1] 刘丽[1] 

机构地区：[1]广东海洋大学水产学院,南海水产经济动物增养殖广东省普通高校重点实验室,广东湛江524088 [2]广东徐闻珊瑚礁国家级自然保护区管理局,广东徐闻524100

出　　处：《热带海洋学报》2016年第3期72-78,共7页Journal of Tropical Oceanography

基　　金：广东省海洋渔业科技推广专项(A201308E02);广东省自然科学基金项目(S2011010000269)~~

摘　　要：以SAM(S-腺苷酰-L-甲硫氨酸)基因作为内参基因,利用实时荧光定量PCR技术对稀杯盔形珊瑚(Galaxea astreata)共生虫黄藻(Symbiodinium spp.)Hsp70、Hsp90、psa A和psb A基因在升温至32℃持续胁迫及恢复至28℃后的表达情况进行了研究。结果表明,升温至32℃时,Hsp70、Hsp90表达量无显著变化(p>0.05),随着高温胁迫的持续,Hsp70与Hsp90的表达量显著增高(p<0.01),到32℃7d时2个基因表达量达到最大值(分别为胁迫前的10.3倍和28.2倍);在随后的降温过程中,Hsp70和Hsp90的表达量显著下降(p<0.05),当温度恢复至28 5d℃时2个基因的表达量均下降至较低水平(分别为胁迫前的0.6倍和2.0倍,p<0.01),且趋于稳定。随着温度的升高,psa A的表达量略有升高(p>0.05),在31 24h℃时表达量达到最高(为胁迫前的1.2倍),随后显著下降(p<0.01);而psb A的表达量随着温度的升高显著增加(p<0.05);在31℃24h时表达量达到最高(为胁迫前的1.9倍),继续升温至32℃持续胁迫24h后才开始显著下降(p<0.01)。当温度降至28℃时,2个基因的表达量有一定程度的增加,但是仍显著低于胁迫前的表达水平(p<0.01),28℃9d时分别为胁迫前的0.27倍和0.15倍,表明热应激可能使虫黄藻的光合功能受到损伤。The relative expressions of stress genes Hsp70,Hsp90 and choloplast psa A,psb A（SAM as reference gene） in Galaxea astreata endosymbiotic zooxanthella（Symbiodinium spp.） under heat stress were detected by using real-time PCR technique.All samples were exposed to elevated temperature at 32 ℃ over a 7-day period,and then the temperature was reduced to 28 ℃ gradually,with the temperature change from 28 ℃ to 32 ℃ at a rate of 1 ℃ per 24 hours.The results showed that the expression patterns of Hsp70 and Hsp90 were similar.The induced expression levels were upregulated but showed no significant difference compared to the control group（p0.05） during the early stage of temperature climbing,subsequently reaching the maximize level after 168 h tolerance period at 32 ℃.The lowest abundance of the gene products was detected when returned to the normal condition of 28 ℃ after 5-day recovery.Moreover,we examined the expression levels of chloroplast psa A and psb A genes stimulated by heat.Both were increased at the initial stage of thermal stress,and reached maximize at 31 ℃ for 24 h,with 1.2 and 1.9 folds compared to the level of the untreated group,respectively.Subsequently at 32 ℃,psb A transcripts maintained the high level until 24 h consecutive hours of stress,while psa A immediately decreased significantly（p0.01）.When temperature recovery reached 28 ℃,the transcripts of the two genes were significantly lower than the initial level（p0.01）,which indicates that the photosynthetic function of endosymbiotic zooxanthella may be injured（or inhibited）.

关 键 词：虫黄藻 基因表达 温度胁迫 

分 类 号：Q949.2[生物学—植物学] Q344.13