Functional architecture of the light-responsive chalcone synthase promoter from parsley.
We have combined in vivo genomic footprinting and light-induced transient expression of chalcone synthase promoter derivatives in parsley protoplasts to identify cis sequences regulating light activation. The parsley chalcone synthase promoter contains two cis "units" that are light-responsive. Each unit is composed of short DNA stretches of approximately 50 base pairs, and each contains two in vivo footprints. One of the footprints in each unit covers a sequence that is highly conserved among other light- and stress-regulated plant genes. The other footprinted sequences in each unit are not related to each other. The TATA distal light-responsive unit is inherently weak but can compensate partially for the loss of the stronger TATA proximal unit. Levels of light-induced expression from either can be influenced by the presence of a region of approximately 100 base pairs located upstream of the TATA distal light-responsive unit. Combination of the light-responsive units and upstream region generates a synergistic response to light. We speculate that functional compensation generated by nonidentical, but sequence-related, cis units foreshadows combinatorial diversity of cognate trans factors.
Schulze-Lefert
P
P
Department of Biochemistry, Max-Planck-Institut für Züchtungsforschung, Köln, Federal Republic of Germany.
Becker-André
M
M
Schulz
W
W
Hahlbrock
K
K
Dangl
J L
JL
D000217:Acyltransferases / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002478:Cells, Cultured; D004247:DNA; D005786:Gene Expression Regulation; D008027:Light; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000528:radiation effects; D011523:Protoplasts; D015183:Restriction Mapping
D004247:DNA; D000217:Acyltransferases; C020141:flavanone synthetase