表达的hrmA蛋白质具有诱导水稻细胞产生防卫反应的活性

 将丁香假单胞菌hrmA基因构建到原核表达载体pET 29中,得到重组载体pET hrmA。将重组载体转化大肠杆菌BL21(DE3),经IPTG诱导,获得了以包含体形式存在的融合蛋白。复性的融合蛋白能诱导水稻悬浮细胞的活性氧迸发,处理20min后达到峰值。Northern杂交结果表明hrmA蛋白能显著地诱导PBZ1基因在水稻悬浮细胞中表达,在所观察的时间内PBZ1基因表达丰度随处理时间延长而增加,用hrmA处理水稻植株,诱导了PAL基因的表达。实验结果表明hrmA融合蛋白具有激活水稻细胞防卫反应的活性。

Expressed hrmA protein induced defense responses in rice

HrmA gene,isolated from Pseudomonas syringae pv. syringae,is functionally like an avirulence gene on the host tobacco plants. In this study,we expressed the recombinant hrmA protein on a pET-29(b) vector in Escherichia coli BL21 (DE3). The hrmA histidine-tagged fusion protein was expressed at very high amount as inclusion bodies. The partial purified proteins were used for the study of biological function on rice. The hrmA protein induced rapidly the burst of active oxygen species in suspension-cultured rice cells,with a peak about 20 min post the treatment. The expression of PBZ1,a pathogenesis-related gene,in hrmA-treated rice cells was observed by northern blot analysis. Treatment of rice seedlings with the recombinant hrmA protein induced strongly the accumulation of mRNA of phenylalanine ammonia-lyase gene. These results suggest that the hrmA protein has an elicitor activity on rice cells.