《植物生理学报》 2015, 51(10): 1640-1648

番茄幼苗血红素加氧酶-1对热激的响应及其抗氧化防护作用

陈笑玥^1,*, 张毅华^1,*, 张耀文², 沈文飚^1,**

¹南京农业大学生命科学学院, 南京210095; ²山西省农业科学院作物科学研究所, 太原030031

通信作者：陈笑玥；E-mail: wbshenh@njau.edu.cn；Tel: 025-84399032

摘　要：

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(ZnPPIX)则加剧热激诱导的氧化胁迫; 此外, ZnPPIX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SlHSP70和SlHSP20基因表达也被显著削弱或延迟, 但SlHSP17.7和SlHSP101的转录本则不受ZnPPIX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。

关键词：血红素加氧酶-1; 热激; 抗氧化防护; 番茄

收稿：2015-04-18   修定：2015-08-29

资助：国家自然科学基金(J1210056和J1310015)。

Response of Tomato Seedlings Heme Oxygenase-1 to Heat Shock Stress and Its Role in Antioxidative Defense

CHEN Xiao-Yue^1,*, ZHANG Yi-Hua^1,*, ZHANG Yao-Wen², SHEN Wen-Biao^1,**

¹College of Life Science, Nanjing Agricultural University, Nanjing 210095, China; ²Crop Research Institute, Shanxi Academy of Agricultural Sciences, Taiyuan 03003¹, China

Corresponding author: CHEN Xiao-Yue; E-mail: wbshenh@njau.edu.cn; Tel: 025-84399032

Abstract:

Upon heat shock stress, plants normally induce heat shock response (HSR). For example, the induction of genes encoding heat shock proteins (HSP) and antioxidant enzymes could protect plants against damages caused by heat stress. However, the detailed inducible mechanism is still elusive. In this study, the response of tomato heme oxygenase-1 (HO-1, EC 1.14.99.3) to heat shock stress and its role in antioxidative defense were investigated. Our results show that heat shock treatment is not only able to time-dependently induce lipid peroxidation and stem elongation inhibition in tomato (Solanum lycopersicum) seedlings, but also increase HO activity and HO-1 protein level. Furthermore, ZnPPIX, the potent inhibitor of HO-1, could aggravate the heat-induced oxidative damage. Meanwhile, the increased HO activity triggered by heat shock was partly blocked by ZnPPIX. Activities of the two antioxidant enzymes, including catalase (CAT) and ascorbate peroxidase (APX), were also differently inhibited by ZnPPIX. Similarly, as for several genes encoding heat shock proteins (HSPs), for example, the up-regulation of SlHSP70 and SlHSP20 was weakened or delayed, respectively. By contrast, the changes of SlHSP17.7 and SlHSP101 transcripts were not affected. In sum, our results suggest that tomato HO-1 is, at least partially, involved in the induction of HSP and heat-induced antioxidative defense.

Key words: heme oxygenase-1; heat shock; antioxidative defense; Solanum lycopersicum