I am having an issue with protein induction. I cloned a gene from Poplar into pProxHTa vector and sequenced it completely. But I dont see any induction of protein. I grow the BL21 cells upto 0.8 OD and induce with 0.1, 0.2 and 0.5 mM IPTG.I have tested multiple temperatures after induction (16,20,25,30 C) and multiple time points (1,3,5,16h). I have also cloned the homolog (95% identical) of this gene in Salix and I didn't have any problem in protein induction(0.1 mM IPTG and 20C for 6h). Any suggestions please..