绿木霉Sm1基因的克隆、原核表达及蛋白纯化

木霉菌(Trichoderma spp.)是土壤内普遍存在的习居菌,具有多种生物防治功能,其中诱导植物免疫反应是重要的生物防治功能之一1].木霉菌Sm1蛋白(small one protein)是从绿木霉(Trichoderma virens)中分离得到的一种低分子量、富含半胱氨酸的疏水性蛋白,属于蛋白类激发子,与Cerato-platanin基因家族有很高的同源性,具有诱导植物免疫抗性的作用2].

Sm1 gene cloning from Trichoderma virens,prokaryotic expression and protein purification

Trichoderma spp.have been recognized as the agents for the biocontrol of plant disease.They produce or release a variety of compounds that induce localized or systemic resistance responses in plants.In this study,Sm1 gene was cloned from Trichoderma virens(YZ2612).Sequence analysis showed that the cDNA fragment had an ORF with length of 414 bp encoding 138 amino acid residues.The recombinant prokar-yotic expression vector pET-28a(+)-Sm1 was constructed,and then transformed into Escherichia coli BL21(DE3).IPTG concentration,induction time and temperature were optimized for enhancing fused protein expression,It was revealed that the best expression was achieved under conditions of 24℃ and 1 mmol/L of IPTG for 4 hours.The recombinant protein was solubilized,denatured,refolded,and purified.These results might offer an important gene resource for being used to construct transgenic resistant lines of plants and to prepare new kind of protein biofungicide.