Regulatory mechanism of plant gene transcription by GT-elements and GT-factors

GT-elements are regulatory DNA sequences usually found in: tandem repeals i n the promoter region of many different plant genes. Depending on promoter structure, GT-elements can have a positive or a negative transcription func tion, The cognate GT-element binding factors contain one or two trihelix DN A binding motifs, which have so far been identified in plant transcription factors only, GT-factors are ubiquitously expressed;: in Arabidopsis they b elong to a small family of transcription factors. The functioning of plant GT-elements and GT-factors shows complex regulatory features of plant gene transcription.