DIFFERENTIAL TRANSCRIPTION OF PEA CHLOROPLAST GENES DURING LIGHT-INDUCED LEAF DEVELOPMENT TRANSCRIPTION - CONTINUOUS FAR-RED LIGHT ACTIVATES CHLOROPLAST TRANSCRIPTION
An. Dubell et Je. Mullet, DIFFERENTIAL TRANSCRIPTION OF PEA CHLOROPLAST GENES DURING LIGHT-INDUCED LEAF DEVELOPMENT TRANSCRIPTION - CONTINUOUS FAR-RED LIGHT ACTIVATES CHLOROPLAST TRANSCRIPTION, Plant physiology, 109(1), 1995, pp. 105-112
Plastid gene expression was analyzed in pea (Pisum sativum L.) plants
grown in darkness, continuous far-red light, and white light. Response
s induced by continuous far-red light were most likely mediated by PHY
A. Plastid transcription activity was low in dark-grown plants. In con
trast, plastids of plants grown in white or far-red light showed a 10-
fold increase in transcription activity between 4 and 6 d postimbibiti
on (dpi) and a decrease between 6 and 9 dpi. Plastid RNAs accumulated
in illuminated plants from 5 to 7 dpi. In far-red-light-illuminated pl
ants, plastid mRNA levels remained elevated until 14 dpi. In white-lig
ht-grown plants, most plastid RNAs decreased in abundance after 7 dpi
to very low levels by 14 dpi. This indicates that white light induces
a general decrease in plastid RNA stability compared to far-red-light-
illuminated seedlings. PsbA mRNA accumulated in older, dark-grown, far
-red, and white-light-illuminated seedlings, consistent with this RNA
having high stability. Transcription of genes encoding the plastid's t
ranscription and translation apparatus increased relative to rbcL and
other genes encoding proteins of the photosynthetic apparatus from 4 t
o 5 dpi and then declined 10-fold from 5 to 9 dpi. These data document
dynamic modulation of plastid gene transcription and mRNA stability d
uring; light-induced chloroplast development in pea.