亚硝酸盐胁迫对凡纳滨对虾肝胰腺抗氧化酶、热休克蛋白和组织蛋白酶B基因表达量的影响

Effects of Nitrite Stress on Gene Expression of Antioxidant Enzymes, Heat Shock Protein and Cathepsin B in Hepatopancreas of Litopenaeus vannamei

用实时荧光定量PCR技术研究在20 mg/L亚硝酸盐胁迫下,凡纳滨对虾(Litopenaeus vannamei)肝胰腺中锰超氧化物歧化酶(Mn-SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)和硫氧还蛋白(TRx)等抗氧化相关酶以及热休克蛋白HSP70、组织蛋白酶B(CTSB)的基因表达量变化。结果表明,与对照组相比,在胁迫24 h时Mn-SOD基因表达量显著升高,CAT基因表达量在12~48 h升高,GPx基因表达量在24和48 h时升高,TRx基因表达量24 h时升高,而后在48和72 h时降低,Hsp70基因表达量在48和72 h时升高,CTSB基因表达量在48 h和72 h时升高,差异均有统计学意义(P<0.05)。在亚硝酸盐胁迫下,抗氧化酶相关基因、Hsp70和CTSB基因的表达量均被显著诱导进行免疫防御,4种抗氧化相关基因和Hsp70、CTSB基因对亚硝酸盐胁迫敏感度不同,在抗亚硝酸盐胁迫过程中有一定协同作用。

The expression level changes of antioxidant enzymes,i.e.manganese-superoxide dismutase(Mn-SOD),catalase(CAT),glutathion peroxidase(GPx)and thioredoxin(TRx),as well as heat shock protein(Hsp70)and cathepsin B(CTSB)in hepatopancreas of the white shrimp Litopenaeus vannamei under nitrite stress(20mg/L)were analyzed by real-time fluorescent quantitative PCR.The results showed that the expression level of Mn-SOD was significantly induced at24h compared with that of the control group.The expression levels of CAT were significantly increased after12-48h.GPx expression levels were up-regulated after24and48h.TRx expression levels were significantly increased at24h,then significantly decreased at48and72h.The expression levels of Hsp70were significantly increased at48and72h.CTSB expression levels were up-regulated at24,48and72h.These results indicated that the mRNA expressions of antioxidant genes,Hsp70and CTSB were induced to protect the hepatopancreas against nitrite stress.Four antioxidant genes,Hsp70and CTSB displayed different sensitivity to nitrite stress,suggesting the synergistic effect of these genes under nitrite stress.