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Analysis of a maize α‐tubulin gene promoter by transient expression and in transgenic tobacco plants
Author(s) -
Rigau Joan,
Capellades Montserrat,
Montoliu Lluis,
Torres Miguel Angel,
Romera Carme,
MartínezIzquierdo José Antonio,
Tagu Denis,
Puigdomènech Pere
Publication year - 1993
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1993.04061043.x
Subject(s) - biology , meristem , gene , transgene , gene expression , promoter , genetically modified crops , regulatory sequence , microbiology and biotechnology , coleoptile , pollen , genetics , botany
The pattern of expression directed by the promoter of the maize Tub α 1 gene was investigated by analysis of chloramphenicol acetyl transferase (CAT) and β‐glucuronidase (GUS) activities in transient expression experiments of maize and tobacco protoplasts. The same promoter was also investigated by histochemical GUS analysis in transgenic tobacco plants containing promoter gene fusions. As determined by histochemical tests, the Tub α 1 promoter gene preferentially directs GUS expression in regenerating root tip meristems and pollen. This pattern corresponds to the distinctive features of natural expression of the gene in maize as determined by Northern analysis. However, no expression is observed in other meristematic tissues of the transgenic tobacco plants, as in shoot apex or in coleoptiles, which is weakly detected in maize. Analysis of the regulatory properties of 5′ promoter deletions showed that the proximal region of the promoter, from positions −1410 or −449 to 15 bp upstream of the ATG, is sufficient to establish the qualitative pattern of expression in transgenic tobacco plants. Deletions to positions −352 or −117 abolished the expression in roots, but not in pollen, suggesting that upstream of these positions there are elements responsible for the pattern in root. Further deletions abolished all the promoter activity, suggesting that this promoter region contains the elements essential for expression in pollen. The different patterns and levels of transient and stable expression are discussed.