THE PLANT CELL, Vol 1, Issue 7 691-698, Copyright © 1989 by American Society of Plant Biologists
cis-Acting Elements for Light Regulation of Pea Ferredoxin I Gene Expression Are Located within Transcribed Sequences
R. C. Elliott, L. F. Dickey, M. J. White and W. F. Thompson
Department of Botany and Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695
An intact pea gene encoding ferredoxin I (Fed-1) and several chimeric
constructs containing portions of Fed-1 were introduced into tobacco plants
by Agrobacterium-mediated transformation. The intact gene was correctly
transcribed and translated to produce a protein that was imported into the
chloroplast and processed to its mature size. Fed-1 mRNA accumulation in
these plants was strongly light-dependent, as it is in pea leaves. In
chimeric constructs, the Fed-1 promoter was active but no light responses
were seen, even when as much as 2 kilobases of 5[prime] -flanking sequence
were included. We also failed to observe clear light responses with a
construct containing 3[prime] -flanking sequences from Fed-1 attached to a
[beta]-glucuronidase gene driven by the cauliflower mosaic virus 35S
promoter. However, the transcribed portion of Fed-1 conveyed normal light
responsiveness when driven by the 35S promoter. The results are discussed
in terms of the hypothesis that light determines Fed-1 mRNA abundance by
affecting RNA stability rather than by affecting transcription.
