THE PLANT CELL, Vol 1, Issue 8 805-813, Copyright © 1989 by American Society of Plant Biologists
Identification of Enhancer Elements in the Upstream Region of the Nuclear Photosynthetic Gene ST-LS1
J. Stockhaus, J. Schell and L. Willmitzer
Institut fur Genbiologische Forschung Berlin GmbH, Ihnestrasse 63, D-1000 Berlin, Federal Republic of Germany
The nuclear gene ST-LS1 from potato encodes a 10-kilodalton protein that is
a component of the oxygen-evolving complex of photosystem II. Analysis of
the expression of a reporter gene driven by chimeric promoters, consisting
of ST-LS1 upstream sequences and a truncated cauliflower mosaic virus 35S
promoter, suggests that a strong positive regulatory element is located
between position -345 and -261, whereas both the region -261 to +11 and the
more upstream region -1600 to -530 are devoid of autonomous strong positive
elements detectable by this approach. The ST-LS1 upstream region contains
redundant elements conferring light-regulated and organ-specific
expression, one of them being located between position -130 and +11. In
addition, enhancer-like sequences conferring light-regulated as well as
organ-specific expression to heterologous promoters were identified. These
sequences are functional not only when located 5[prime]-upstream of the
coding region but also when placed 3[prime]-downstream of the
polyadenylation signal, thus representing one of the first examples of a
plant gene-derived enhancer being able to induce a truncated heterologous
promoter from a position 3[prime]-downstream of the transcription unit.
