ISSN:
1573-5028
Keywords:
pollen-specific gene expression
;
promoter analysis
;
transient assays
;
Tradescantia
;
Zea mays
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We have previously reported the isolation and characterization of a gene (Zm 13) from Zea mays which shows a pollen-specific pattern of expression. Stably transformed tobacco plants containing a reporter gene linked to portions of the Zm 13 5′ flanking region show correct temporal and spatial expression of the gene. Here we present a more detailed analysis of the 5′ regions responsible for expression in pollen by utilizing a transient expression system. Constructs containing the β-glucuronidase (GUS) gene under the control of various sized fragments of the Zm13 5′ flanking region were introduced into Tradescantia and Zea mays pollen via high-velocity microprojectile bombardment, and monitored both visually and with a fluorescence assay. The results suggest that sequences necessary for expression in pollen are present in a region from −100 to −54, while other sequences which amplify that expression reside between −260 and −100. The replacement of the normal terminator with a portion of the Zm13 3′ region containing the putative polyadenylation signal and site also increased GUS expression. While the −260 to −100 region contains sequences similar to other protein-binding domains reported for plants, the −100 to −54 region appears to contain no significant homology to other known promoter fragments which direct pollen-specific expression. The microprojectile bombardment of Tradescantia pollen appears to be a good test system for assaying maize and possibly other monocot promoter constructs for pollen expression.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00034950
