Editing TATA box (section)

=== Insertions or deletions ===
One of the first studies of TATA box [[mutation]]s looked at a sequence of DNA from ''[[Agrobacterium tumefaciens]]'' for the octopine type [[Cytokinin signaling and response regulator protein|cytokinin gene]].<ref name=":5" /> This specific gene has three TATA boxes. A [[phenotype]] change was only observed when all three TATA boxes were deleted. An [[Insertion (genetics)|insertion]] of extra base pairs between the last TATA box and the transcription start site resulted in a shift in the start site; thus, resulting in a phenotypic change.&nbsp; From this original [[mutation]] study, a change in transcription can be seen when there is no TATA box to promote transcription, but transcription of a gene will occur when there is an [[Insertion (genetics)|insertion]] to the sequence.&nbsp;The nature of the resulting phenotype may be affected due to the [[Insertion (genetics)|insertion]].

[[Mutation]]s in [[maize]] [[Promoter (genetics)|promoters]] affect the expression of the [[Promoter (genetics)|promoter]] [[gene]]s in a plant-organ-specific manner.<ref name=":19">{{cite journal | vauthors = Kloeckener-Gruissem B, Vogel JM, Freeling M | title = The TATA box promoter region of maize Adh1 affects its organ-specific expression | journal = The EMBO Journal | volume = 11 | issue = 1 | pages = 157–66 | date = January 1992 | pmid = 1740103 | pmc=556436| doi = 10.1002/j.1460-2075.1992.tb05038.x }}</ref> A [[Duplication (chromosomal)|duplication]] of the TATA box leads to a significant decrease in [[Enzyme|enzymatic activity]] in the [[Scutellum (botany)|scutellum]] and [[root]]s, leaving [[pollen]] enzymatic levels unaffected. A [[Deletion (genetics)|deletion]] of the TATA box leads to a small decrease in [[Enzyme|enzymatic activity]] in the [[Scutellum (botany)|scutellum]] and [[root]]s, but a large decrease in [[Enzyme|enzymatic levels]] in [[pollen]].<ref name=":19" />