TY - JOUR
T1 - Light-induced transcriptional repression of the pea AS1 gene
T2 - Identification of cis-elements and transfactors
AU - Ngai, Nora
AU - Tsai, Fong Ying
AU - Coruzzi, Gloria
PY - 1997
Y1 - 1997
N2 - Here, we examine the cis-elements and trans-factors affecting the expression of asparagine synthetase (AS) genes whose transcription is negatively regulated by light. The promoters for the AS1 and AS2 genes of pea were isolated, sequenced, and functionally dissected for their ability to confer regulated expression to the GUS reporter gene in transgenic tobacco. Histochemical analysis of transgenic plants demonstrated that the AS1 and AS2 promoters show identical patterns of cell-specific expression. The more highly active AS1 promoter was further demonstrated to confer negative light-regulation to the GUS gene in transgenic tobacco. Deletion analysis and gain-of-function experiments showed that 124 bp of the AS1 promoter was sufficient to confer light-activated repression to a heterologous promoter. Potential conserved transcription regulatory elements, Box B, Box C, and Box C' within this region were shown to bind to nuclear proteins by gel shift analysis. A light-specific DNA:protein interaction was detected with Box B. The nuclear factors that bind to Box C and C' elements of AS1 are competed by a putative repressor element 'RE1' defined previously in the oat phytochrome gene whose transcription is also repressed by light. The Box B and C/C'-Box/RE1-binding factors were found in nuclear extracts of tobacco, pea, and Arabidopsis and may therefore be universal factors involved in light-activated transcriptional repression.
AB - Here, we examine the cis-elements and trans-factors affecting the expression of asparagine synthetase (AS) genes whose transcription is negatively regulated by light. The promoters for the AS1 and AS2 genes of pea were isolated, sequenced, and functionally dissected for their ability to confer regulated expression to the GUS reporter gene in transgenic tobacco. Histochemical analysis of transgenic plants demonstrated that the AS1 and AS2 promoters show identical patterns of cell-specific expression. The more highly active AS1 promoter was further demonstrated to confer negative light-regulation to the GUS gene in transgenic tobacco. Deletion analysis and gain-of-function experiments showed that 124 bp of the AS1 promoter was sufficient to confer light-activated repression to a heterologous promoter. Potential conserved transcription regulatory elements, Box B, Box C, and Box C' within this region were shown to bind to nuclear proteins by gel shift analysis. A light-specific DNA:protein interaction was detected with Box B. The nuclear factors that bind to Box C and C' elements of AS1 are competed by a putative repressor element 'RE1' defined previously in the oat phytochrome gene whose transcription is also repressed by light. The Box B and C/C'-Box/RE1-binding factors were found in nuclear extracts of tobacco, pea, and Arabidopsis and may therefore be universal factors involved in light-activated transcriptional repression.
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U2 - 10.1046/j.1365-313X.1997.12051021.x
DO - 10.1046/j.1365-313X.1997.12051021.x
M3 - Article
C2 - 9418044
AN - SCOPUS:0031279171
SN - 0960-7412
VL - 12
SP - 1021
EP - 1034
JO - Plant Journal
JF - Plant Journal
IS - 5
ER -