Abstract
Irradiation of previously dark-grown cell suspension cultures from parsley (Petroselinum hortense Hoffm.) with ultraviolet light caused large, concomitant increases in mRNA activities for two characteristic enzymes of phenylpropanoid metabolism, phenylalanine ammonia-lyase, and flavanone synthase. The rates of enzyme synthesis both in vitro in a reticulocyte lysate and in vivo were quantitated by direct immunoprecipitation of the labeled enzyme subunits. Following a period of about 2 h, during which possible changes were below the limits of detectability, the two mRNA activities increased rapidly in irradiated cells for serveral hours. Phenylalanine ammonia-lyase mRNA reached a peak in activity a few hours earlier than flavanone synthase mRNA. The apparent half-lives of the enzyme activities were about 7 to 10 h for phenylalanine ammonia-lyase and 5 to 7 h for flavanone synthase. These data were used to calculate the expected, light-induced changes in enzyme activity from the measured changes in mRNA activity. The results for both enzymes were in agreement with experimental data, indicating that the light-induced changes in enzyme activity can be explained by changes in the respective mRNA activity. Some data concerning changes in the degree of polyadenylation of the mRNAs and the inhibitory effects of 7-methylguanosine 5'-phosphate are presented.
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Claims 6
Claim · model-written summary
UV irradiation of previously dark-grown parsley cell suspension cultures caused large, concomitant increases in mRNA activities for phenylalanine ammonia-lyase and flavanone synthase.
- Taxon
- parsley
Petroselinum crispume0 - Organ / stage
- cell suspension culturese0
- Treatment
- ultraviolet lighte0
- Gene
- phenylalanine ammonia-lyase, and flavanone synthasee0
- Outcome
- mRNA activitiese0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Irradiation of previously dark-grown cell suspension cultures from parsley (Petroselinum hortense Hoffm.) with ultraviolet light caused large, concomitant increases in mRNA activities for two characteristic enzymes of phenylpropanoid metabolism, phenylalanine ammonia-lyase, and flavanone synthase”
Claim · model-written summary
In irradiated parsley cells, mRNA activities rose rapidly for several hours after a period of about 2 h with no detectable change.
- Taxon
- parsleyPetroselinum crispume0
- Outcome
- mRNA activitiese1
- Direction
- increased rapidlye1
- Qualifier
- Following a period of about 2 he1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“parsley”
e1“Following a period of about 2 h, during which possible changes were below the limits of detectability, the two mRNA activities increased rapidly in irradiated cells for serveral hours”
Claim · model-written summary
Phenylalanine ammonia-lyase mRNA peaked in activity a few hours earlier than flavanone synthase mRNA in irradiated parsley cells.
- Taxon
- parsleyPetroselinum crispume0
- Gene
- Phenylalanine ammonia-lyasee1
- Outcome
- peak in activitye1
- Direction
- earliere1
- Comparator
- flavanone synthase mRNAe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“parsley”
e1“Phenylalanine ammonia-lyase mRNA reached a peak in activity a few hours earlier than flavanone synthase mRNA”
Claim · model-written summary
The apparent half-life of phenylalanine ammonia-lyase enzyme activity was about 7 to 10 h in irradiated parsley cells.
- Taxon
- parsleyPetroselinum crispume0
- Gene
- phenylalanine ammonia-lyasee1
- Outcome
- apparent half-lives of the enzyme activitiese1
- Value
- 7 to 10 he1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“parsley”
e1“The apparent half-lives of the enzyme activities were about 7 to 10 h for phenylalanine ammonia-lyase and 5 to 7 h for flavanone synthase”
Claim · model-written summary
The apparent half-life of flavanone synthase enzyme activity was about 5 to 7 h in irradiated parsley cells.
- Taxon
- parsleyPetroselinum crispume0
- Gene
- flavanone synthasee1
- Outcome
- apparent half-lives of the enzyme activitiese1
- Value
- 5 to 7 he1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“parsley”
e1“The apparent half-lives of the enzyme activities were about 7 to 10 h for phenylalanine ammonia-lyase and 5 to 7 h for flavanone synthase”
Claim · model-written summary
The authors conclude that light-induced changes in enzyme activity can be explained by changes in the respective mRNA activity, since calculated changes agreed with experimental data for both enzymes.
- Taxon
- parsleyPetroselinum crispume0
- Outcome
- light-induced changes in enzyme activitye1
- Qualifier
- changes in the respective mRNA activitye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“parsley”
e1“The results for both enzymes were in agreement with experimental data, indicating that the light-induced changes in enzyme activity can be explained by changes in the respective mRNA activity”