Photooxidation of Plastids Inhibits Transcription of Nuclear Encoded Genes in Rye (Secale cereale)

Rye ( Secale cereale cv Halo) seedlings treated with the herbicide Norflurazon SAN 9789 showed a reduced concentration of mRNA for the small subunit of ribulose-1,5-bisphosphate carboxylase and for the light-harvesting chlorophyll a / b protein. The inhibition of mRNA accumulation by Norflurazon occurred only in the presence of high light intensities and only after a period of days. The primary effect was an inhibition of the transcription rate that occurred within 1 day after exposure of the seedlings to light.