PLANT PHYSIOLOGY , Vol 104, Issue 3 997-1006, Copyright © 1994 by American Society of Plant Biologists
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MOLECULAR BIOLOGY AND GENE REGULATION |
Promoters from Genes for Plastid Proteins Possess Regions with Different Sensitivities toward Red and Blue Light
T. Lubberstedt, CEH. Bolle, S. Sopory, K. Flieger, R. G. Herrmann and R. Oelmuller
Botanisches Institut der Ludwig-Maximilians-Universitat, Menzingerstrasse 67, 80638 Munchen, Germany
The light-regulated expression of eight nuclear-encoded genes for plastid
proteins from spinach (Spinacia oleracea) (RBCS-1 and CAB-1; ATPC and ATPD,
encoding the subunits [gamma] and [delta] of the ATP synthase; PC and FNR;
PSAD and PSAF, encoding the subunits II and III of photosystem I reaction
center) was analyzed with promoter/[beta]-glucuronidase (GUS) gene fusions
in transgenic tobacco (Nicotiana tabacum and Nicotiana plumbaginifolia)
seedlings and mature plants under standardized light and growth conditions.
Unique response patterns were found for each of these promoters. GUS
activities differed more than 30-fold. Strong promoters were found for the
PC and PSAD genes. On the other hand, the ATPC promoter was relatively
weak. Expression of the CAB/GUS gene fusion in etiolated material was at
the detection limit; all other chimeric genes were expressed in the dark as
well. Light stimulation of GUS activities ranged from 3- (FNR promoter) to
more than 100-fold (CAB-1 promoter). The FNR promoter responded only to red
light (RL) and not significantly to blue light (BL), whereas the PC
promoter contained regions with different sensitivities toward RL and BL.
Furthermore, different RNA accumulation kinetics were observed for the
PSAF, CAB, FNR, and PC promoter/GUS gene fusions during de-etiolation,
which, at least in the case of the PSAF gene, differed from the regulation
of the corresponding endogenous genes in spinach and tobacco. The results
suggest either that not all cis elements determining light-regulated and
quantitative expression are present on the spinach promoter fragments used
or that the spinach cis-regulatory elements respond differently to the host
(tobacco) regulatory pathway(s). Furthermore, as in tobacco, but not in
spinach, the trans-gene hardly responds to single light pulses that operate
through phytochrome. Taken together, the results suggest that the genes
have been independently translocated from the organelle to the nucleus
during phylogeny. Furthermore, each gene seems to have acquired a unique
set of regulatory elements.
