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植物受到高温胁迫以后,会通过诱导热激响应(HSR)包括诱导热激蛋白(HSP)和抗氧化酶编码基因的表达来缓解胁迫造成的伤害,但是不清楚其具体的诱导机理。本实验以番茄(Solanum lycopersicum)‘苏红2003’幼苗为材料,研究了血红素加氧酶-1(HO-1,EC 1.14.99.3)对热激的响应及其抗氧化防护作用。结果表明,45℃热激3 h内不但能以时间依赖性的方式诱导番茄幼苗脂质过氧化和抑制茎生长,还能上调HO的活性和HO-1蛋白水平;进一步加入HO-1的活性抑制剂锌原卟啉IX(Zn PPIX)则加剧热激诱导的氧化胁迫;此外,Zn PPIX还能部分阻断热激诱导的HO活性上调,同时热激诱导的两种抗氧化酶——过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性明显受到抑制,编码热激蛋白的Sl HSP70和Sl HSP20基因表达也被显著削弱或延迟,但Sl HSP17.7和Sl HSP101的转录本则不受Zn PPIX的影响。以上的研究结果表明,番茄HO-1能够部分参与HSP的诱导和抗氧化防护。
After being exposed to heat stress, plants can alleviate the damage caused by stress by inducing the expression of heat shock response (HSR), including the induction of heat shock protein (HSP) and anti-oxidase genes, but the specific induction mechanism is not clear. Solanum lycopersicum ’Suhong 2003’ seedlings were used to study the response of heme oxygenase-1 (HO-1, EC 1.14.99.3) to heat shock and its antioxidative protective effect. The results showed that heat shock at 45 ℃ for 3 h not only induced lipid peroxidation and inhibited stem cell growth but also increased HO activity and HO-1 protein level in tomato seedlings in a time-dependent manner. The activity of HO-1 was further increased In addition, Zn PPIX can partially block heat-induced HO activity upregulation, while heat-induced two antioxidant enzymes - Catalase (CAT) and ascorbate peroxidase (APX) activity were significantly inhibited, and the expression of heat shock protein Sl HSP70 and Sl HSP20 gene expression was significantly weakened or delayed, but the transcription of Sl HSP17.7 and Sl HSP101 It is not affected by Zn PPIX. The above results show that tomato HO-1 can partially participate in the induction of HSP and antioxidant protection.