鼠尾藻hsp70基因的克隆及温度、盐度对其表达的影响

Isolation of Sargassum thunbergii hsp70 Gene and Its Expression Analysis at Different Temperatures and Salinities

为研究温度、盐度及其处理时间对鼠尾藻(Sargassum thunbergii)hsp70表达水平的影响,以β-actin为内参基因,通过RT-qPCR测定不同处理下鼠尾藻幼苗的hsp70表达水平。温度实验设置7个处理组(5、10、15、25、30、35和40℃)、盐度实验设置5个处理组(0、10、20、40和50),以温度20℃、盐度31为对照组;温度处理时间实验在温度35℃下热激不同时间(0、1、2、3、4、6、8、10和12h),盐度处理时间实验在盐度50下处理不同时间(0、1、2、3、4、6、8、10和12h)。研究显示:(1)在不同温度下处理鼠尾藻幼苗1h,40℃组的hsp70表达水平最高,是对照组(20℃)的8.6倍,恢复处理1h后,5℃组与对照组差异不显著,35、40℃组与对照组仍差异显著;(2)鼠尾藻幼苗在(0、10、20、31、40、50)盐度下处理2h,发现0、10、40、50盐度组的hsp70表达水平显著高于对照组,恢复处理2h后,0盐度组鼠尾藻幼苗的hsp70表达水平最高;(3)将鼠尾藻幼苗在35℃下热激不同时间,样品的hsp70表达水平先上升后下降,热激4h时表达量最大,不同热激时间处理组在20℃中恢复1h后,处理1、2和3h的实验组在恢复后hsp70表达水平高于相应的处理组;(4)将鼠尾藻幼苗在盐度50中培养不同时间,样品的hsp70表达水平先升高后下降,在6h时达到最高,不同盐度时间处理组在盐度31下恢复2h后,其hsp70表达水平变化情况与35℃热激不同时间各处理组的变化趋势相同。研究结果表明,在本研究中,鼠尾藻hsp70表达水平在温度40℃、盐度50、高温热激4h和高盐处理6h情况下分别达到最大值,调控效果显著,说明HSP70可能参与了各胁迫下的生物代谢和抗逆反应。

A cDNA fragment encoding the HSP70 of Sargassumthunbergiiwas isolated using RT-PCR technique.Withβ-actin as the internal control,relative abundance of hsp70 transcripts of S.thunbergiiat different temperatures and salinities was determinedwithRT-qPCR.S.thunbergii was cultured at different temperatures for 1hor different salinities for 2h.It was also kept at 35℃ or at 50 psu salinity for different durations.The results showed that（1）at different temperatures（5,10,15,20,25,30,35 and 40℃）for 1h,the abundance of hsp70 transcripts at 40℃ was the highest,8.6folds higher than that at 20℃.After an 1hrecovery,the difference between 5℃and control was not significant while that between 35℃and 40℃was significant;（2）at different salinities（0,10,20,31,40 and 50）for 2h,the abundance of hsp70 transcripts at 0,10,40 and 50psu was significantly higher than that at 30 psu while that after recoveryat 0psu for 2hwas the highest;（3）at 35℃for different durations（0,1,2,3,4,6,8,10 and 12）,the expression of hsp70 showed a trend of rising first and falling then,reaching the top at4 h,and for less than 3h,the expression increased after an 1hrecovery;and（4）at 50 psu for different durations（0,1,2,3,4,6,8,10 and 12h）,the abundance of hsp70 transcripts showed a trend of rising first and falling then,reaching the highest after 6hwhile after recovery at 30 psu for 2h,the expression of hsp70 showed the same trend as that at 35℃.The results showed that the expression of hsp70 was influenced by high temperatures and salinities.Such response may participate in the physiology processes of stress resistance.