Abstract
Ascorbate oxidase expression in pumpkin (Cucurbita spp.) tissues was studied. Specific ascorbate oxidase activities in pumpkin leaf and stem tissues were about 2 and 1.5 times that in the fruit tissues, respectively. In seeds, little ascorbate oxidase activity was detected. Northern blot analyses showed an abundant ascorbate oxidase mRNA in leaf and stem tissues. Fruit tissues had lower levels of ascorbate oxidase mRNA than leaf and stem tissues. Ascorbate oxidase mRNA was not detected in seeds. Specific ascorbate oxidase activity gradually increased during early seedling growth of pumpkin seeds. The increase was accompanied by an increase in ascorbate oxidase mRNA. When ascorbate oxidase activity in developing pumpkin fruits was investigated, the activities in immature fruits that are rapidly growing at 0, 2, 4, and 7 d after anthesis were much higher than those in mature fruits at 14 and 30 d after anthesis. The specific activity and mRNA of ascorbate oxidase markedly increased after inoculation of pumpkin fruit tissues into Murashige and Skoog's culture medium in the presence of an auxin such as 2,4-dichlorophenoxyacetic acid (2,4-D) but not in the absence of 2,4-D. In the presence of 10 mg/L of 2,4-D, ascorbate oxidase mRNA was the most abundant. Thus, ascorbate oxidase is induced by 2,4-D. These results indicate that ascorbate oxidase is involved in cell growth. In pumpkin callus, ascorbate oxidase activity could be markedly increased by adding copper. Furthermore, immunological blotting showed that the amount of ascorbate oxidase protein was also increased by adding copper. However, northern blot analyses showed that ascorbate oxidase mRNA was not increased by adding copper. We suggest that copper may control ascorbate oxidase expression at translation or at a site after translation.
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Claims 17
Claim · model-written summary
Leaf ascorbate oxidase activity was about twice fruit activity.
Verbatim
e0“Specific ascorbate oxidase activities in pumpkin leaf and stem tissues were about 2 and 1.5 times that in the fruit tissues, respectively.”
Claim · model-written summary
Stem ascorbate oxidase activity was about 1.5 times fruit activity.
Verbatim
e0“Specific ascorbate oxidase activities in pumpkin leaf and stem tissues were about 2 and 1.5 times that in the fruit tissues, respectively.”
Claim · model-written summary
Seeds had little ascorbate oxidase activity.
Verbatim
e0“In seeds, little ascorbate oxidase activity was detected.”
t0“Pumpkin”
Claim · model-written summary
Ascorbate oxidase mRNA was abundant in pumpkin leaves and stems.
Verbatim
e0“Northern blot analyses showed an abundant ascorbate oxidase mRNA in leaf and stem tissues.”
t0“Pumpkin”
Claim · model-written summary
Fruit ascorbate oxidase mRNA was lower than in leaves and stems.
Verbatim
e0“Fruit tissues had lower levels of ascorbate oxidase mRNA than leaf and stem tissues.”
t0“Pumpkin”
Claim · model-written summary
Ascorbate oxidase mRNA was undetected in pumpkin seeds.
Verbatim
e0“Ascorbate oxidase mRNA was not detected in seeds.”
t0“Pumpkin”
Claim · model-written summary
Specific ascorbate oxidase activity rose during early seedling growth.
Verbatim
e0“Specific ascorbate oxidase activity gradually increased during early seedling growth of pumpkin seeds.”
Claim · model-written summary
Ascorbate oxidase mRNA also increased during early seedling growth.
Verbatim
e0“The increase was accompanied by an increase in ascorbate oxidase mRNA.”
t0“Pumpkin”
Claim · model-written summary
Immature rapidly growing pumpkin fruits had much higher ascorbate oxidase activity than mature fruits.
Verbatim
e0“When ascorbate oxidase activity in developing pumpkin fruits was investigated, the activities in immature fruits that are rapidly growing at 0, 2, 4, and 7 d after anthesis were much higher than those in mature fruits at 14 and 30 d after anthesis.”
t0“pumpkin”
Claim · model-written summary
2,4-D increased ascorbate oxidase activity in cultured pumpkin fruit tissue.
Verbatim
e0“The specific activity and mRNA of ascorbate oxidase markedly increased after inoculation of pumpkin fruit tissues into Murashige and Skoog's culture medium in the presence of an auxin such as 2,4-dichlorophenoxyacetic acid (2,4-D) but not in the absence of 2,4-D.”
Claim · model-written summary
2,4-D increased ascorbate oxidase mRNA in cultured pumpkin fruit tissue.
Verbatim
e0“The specific activity and mRNA of ascorbate oxidase markedly increased after inoculation of pumpkin fruit tissues into Murashige and Skoog's culture medium in the presence of an auxin such as 2,4-dichlorophenoxyacetic acid (2,4-D) but not in the absence of 2,4-D.”
Claim · model-written summary
Ascorbate oxidase mRNA was most abundant at 10 mg/L 2,4-D.
- Taxon
- pumpkint0
- Treatment
- 10 mg/L of 2,4-De0
- Gene
- ascorbate oxidasee0
- Outcome
- ascorbate oxidase mRNAe0
- Direction
- most abundante0
Not reportedComparator
Verbatim
e0“In the presence of 10 mg/L of 2,4-D, ascorbate oxidase mRNA was the most abundant.”
t0“pumpkin”
Claim · model-written summary
The authors infer that ascorbate oxidase participates in cell growth.
Verbatim
e0“These results indicate that ascorbate oxidase is involved in cell growth.”
t0“Pumpkin”
Claim · model-written summary
Copper increased ascorbate oxidase activity in pumpkin callus.
- Taxon
- pumpkine0
- Organ / stage
- calluse0
- Treatment
- adding coppere0
- Gene
- ascorbate oxidasee0
- Outcome
- ascorbate oxidase activitye0
- Direction
- markedly increasede0
Not reportedComparator
Verbatim
e0“In pumpkin callus, ascorbate oxidase activity could be markedly increased by adding copper.”
Claim · model-written summary
Copper increased ascorbate oxidase protein abundance.
- Taxon
- Pumpkint0
- Treatment
- adding coppere0
- Gene
- ascorbate oxidase proteine0
- Outcome
- amount of ascorbate oxidase proteine0
- Direction
- increasede0
Not reportedComparator
Verbatim
e0“Furthermore, immunological blotting showed that the amount of ascorbate oxidase protein was also increased by adding copper.”
t0“Pumpkin”
Claim · model-written summary
Copper did not increase ascorbate oxidase mRNA.
- Taxon
- Pumpkint0
- Treatment
- adding coppere0
- Gene
- ascorbate oxidasee0
- Outcome
- ascorbate oxidase mRNAe0
- Direction
- not increasede0
Not reportedComparator
Verbatim
e0“However, northern blot analyses showed that ascorbate oxidase mRNA was not increased by adding copper.”
t0“Pumpkin”
Claim · model-written summary
Copper may regulate ascorbate oxidase at translation or a later step.
Verbatim
e0“We suggest that copper may control ascorbate oxidase expression at translation or at a site after translation.”
t0“Pumpkin”
The same questions in other papers
copper atom · quality: protein · Cucurbita (pumpkins)Positive and negative results
1 in the opposite direction
- negative
copper atom · physiology: enzyme activity · Cucurbita (pumpkins)Positive and negative results
1 in the opposite direction
- no effect
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.