The β-glucosidase, which hydrolyzes the β(1–4) glucosidic linkage of disaccharides, oligosaccharides and glucose-substituted molecules, has been used in many biotechnological applications. The current commercial source of β-glucosidase is mainly microbial fermentation. Plants have been developed as bioreactors to produce various kinds of proteins including β-glucosidase because of the potential low cost. Sulfolobus solfataricus is a thermoacidophilic archaeon that can grow optimally at high temperature, around 80 °C, and pH 2–4. We overexpressed the β-glucosidase gene from S. solfataricus in transgenic tobacco via Agrobacteria-mediated transformation. Three transgenic tobacco lines with β-glucosidase gene expression driven by the rbcS promoter were obtained, and the recombinant proteins were accumulated in chloroplasts, endoplasmic reticulum and vacuoles up to 1%, 0.6% and 0.3% of total soluble protein, respectively. By stacking the transgenes via crossing distinct transgenic events, the level of β-glucosidase in plants could further increase. The plant-expressed β-glucosidase had optimal activity at 80 °C and pH 5–6. In addition, the plant-expressed β-glucosidase showed high thermostability; on heat pre-treatment at 80 °C for 2 h, approximately 70% residual activity remained. Furthermore, wind-dried leaf tissues of transgenic plants showed good stability in short-term storage at room temperature, with β-glucosidase activity of about 80% still remaining after 1 week of storage as compared with fresh leaf. Furthermore, we demonstrated the possibility of using the archaebacterial β-glucosidase gene as a reporter in plants based on alternative β-galactosidase activity.

β-葡萄糖苷酶可水解二糖、寡糖和葡萄糖取代分子的 β(1-4) 糖苷键，已用于许多生物技术应用。目前β-葡萄糖苷酶的商业来源主要是微生物发酵。由于潜在的低成本，植物已被开发为生物反应器以生产包括β-葡萄糖苷酶在内的各种蛋白质。Sulfolobus solfataricus是一种嗜热嗜酸菌，可以在 80 °C 左右的高温和 pH 2-4 下最佳生长。我们通过农杆菌介导的转化在转基因烟草中过表达来自S. solfataricus的 β-葡萄糖苷酶基因。由rbcS驱动的具有 β-葡萄糖苷酶基因表达的三个转基因烟草品系获得启动子后，重组蛋白在叶绿体、内质网和液泡中的积累量分别达到总可溶性蛋白的 1%、0.6% 和 0.3%。通过跨越不同的转基因事件堆叠转基因，植物中β-葡萄糖苷酶的水平可以进一步增加。植物表达的 β-葡萄糖苷酶在 80 °C 和 pH 5-6 时具有最佳活性。此外，植物表达的β-葡萄糖苷酶表现出较高的热稳定性；在 80°C 下热处理 2 小时后，大约 70% 的残留活性仍然存在。此外，转基因植物风干叶组织在室温短期储存中表现出良好的稳定性，与新鲜叶片相比，储存1周后β-葡萄糖苷酶活性仍保持在80%左右。此外，