a promoter that is active under environmental or developmental regulation
                                                            
                                                     
                        
                                                
                        
                        
                            a promoter that is capable of directly or indirectly activating transcription of a DNA sequence in response to an inducer
                                                            
                                                     
                        
                                                
                        
                        
                            a promoter that is capable of directly or indirectly activating transcription of one or more DNA sequences or genes in response to an inducer