Abstract
The accumulation of Cat3 catalase mRNA in the green leaves of maize (Zea mays) exhibits an unusual circadian rhythm. The steady-state level of the Cat3 transcript varies dramatically over the day in seedlings grown on a 12-hr photoperiod. Low or undetectable levels of the Cat3 mRNA are found late in the dark and early in the light period, while the transcript accumulates to high levels late in the light and early in the dark period. This dramatic diurnal variation in mRNA level does not occur with the maize Cat1 or Cat2 catalase transcripts. The diurnal fluctuation in Cat3 mRNA persists when the seedlings are transferred to continuous light or darkness, which indicates the influence of a circadian rhythm. The lack of influence of red and/or far-red light on this diurnal variation in transcript level indicates that the circadian rhythm is not regulated by phytochrome. Run-on transcription assays show that changes in the rate of Cat3 gene transcription closely parallel the observed changes in steady-state mRNA levels. This circadian rhythm in Cat3 gene expression and the resulting high levels of mRNA which accumulate late in the light period suggest that the catalase 3 (CAT-3) isozyme is being synthesized for accumulation in the dark period. This, together with the high level of Cat3 mRNA and CAT-3 protein accumulation in dark-grown maize shoots, suggests that the activity of the CAT-3 isozyme might be associated with a metabolic process important in shoot cells in the dark.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 9
Claim · model-written summary
Maize Cat3 transcript levels vary dramatically over the day under a 12-hour photoperiod.
- Gene
- Cat3e0
- Outcome
- steady-state level of the Cat3 transcripte0
- Direction
- varies dramaticallye0
- Qualifier
- 12-hr photoperiode0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The steady-state level of the Cat3 transcript varies dramatically over the day in seedlings grown on a 12-hr photoperiod.”
t0“maize”
Claim · model-written summary
Cat3 mRNA is low or undetectable late in darkness and early in light.
- Gene
- Cat3e0
- Outcome
- levels of the Cat3 mRNAe0
- Direction
- Low or undetectablee0
- Qualifier
- late in the dark and early in the light periode0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Low or undetectable levels of the Cat3 mRNA are found late in the dark and early in the light period”
t0“maize”
Claim · model-written summary
Cat3 mRNA accumulates to high levels late in light and early in darkness.
Not reportedGene
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the transcript accumulates to high levels late in the light and early in the dark period”
t0“maize”
Claim · model-written summary
Cat1 and Cat2 transcripts lack the Cat3 diurnal variation.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This dramatic diurnal variation in mRNA level does not occur with the maize Cat1 or Cat2 catalase transcripts.”
Claim · model-written summary
Cat3 mRNA fluctuation persists under continuous light or darkness.
- Treatment
- continuous light or darknesse0
- Gene
- Cat3e0
- Outcome
- diurnal fluctuation in Cat3 mRNAe0
- Direction
- persistse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The diurnal fluctuation in Cat3 mRNA persists when the seedlings are transferred to continuous light or darkness”
t0“maize”
Claim · model-written summary
Red or far-red light does not influence Cat3 transcript diurnal variation.
- Treatment
- red and/or far-red lighte0
- Outcome
- diurnal variation in transcript levele0
- Direction
- lack of influencee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The lack of influence of red and/or far-red light on this diurnal variation in transcript level indicates that the circadian rhythm is not regulated by phytochrome.”
t0“maize”
Claim · model-written summary
Cat3 transcription-rate changes closely parallel steady-state mRNA changes.
- Gene
- Cat3e0
- Outcome
- changes in steady-state mRNA levelse0
- Qualifier
- changes in the rate of Cat3 gene transcriptione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“changes in the rate of Cat3 gene transcription closely parallel the observed changes in steady-state mRNA levels.”
t0“maize”
Claim · model-written summary
Cat3 mRNA and CAT-3 protein accumulate at high levels in dark-grown maize shoots.
- Organ / stage
- shootse0
- Gene
- Cat3e0
- Outcome
- Cat3 mRNA and CAT-3 protein accumulatione0
- Direction
- high levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high level of Cat3 mRNA and CAT-3 protein accumulation in dark-grown maize shoots”
Claim · model-written summary
Authors suggest CAT-3 activity may be associated with a dark-period metabolic process in shoots.
- Organ / stage
- shoot cellse0
- Gene
- CAT-3e0
- Outcome
- activity of the CAT-3 isozymee0
- Qualifier
- might be associated with a metabolic process important in shoot cells in the darke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“suggests that the activity of the CAT-3 isozyme might be associated with a metabolic process important in shoot cells in the dark.”
t0“maize”
The same questions in other papers
light · molecular: expression · Zea mays (maize)Positive and negative results
11 papers in the same direction as this paper · 18 in the opposite direction
- positive
- positive
- positive
26 papers more in this group
See all 30 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.