Abstract
The loss of morphogenetic potential in bean suspension cultures has been investigated by measuring the amounts of phenylalanine ammonia-lyase activity induced in the cells when they are transferred from a medium in which they are grown and maintained to an induction medium. The tissue has been grown in 2 types of medium: (1) supplemented with 2,4-dichlorophenoxyacetic acid as the only growth hormone, and (2) supplemented with 2,4-dichlorophenoxyacetic acid and coconut milk. When cells were grown in medium with only 2,4-dichlorophenoxyacetic acid for a period of 5--10 subcultures and samples were transferred to the induction medium at intervals during the subcultures, the amounts of phenylalanine ammonia-lyase activity and the number of xylem elements induced progressively declined. Cells grown in the presence of coconut milk did not lose the ability to induce phenylalanine ammonia-lyase or xylem elements. Cells grown in the presence of coconut milk were cloned and clones capable of producing different amounts of phenylalanine ammonia-lyase when transferred to induction medium were obtained. However, clones producing low amounts of activity did not grow faster in the medium lacking coconut milk and no evidence was obtained to show that selective growth of non-inducible cells was responsible for the loss of morphogenetic potential. In addition to the induction brought about by the presence of naphthylacetic acid and kinetin in the induction medium the cells could also be stimulated to produce phenylalanine ammonia-lyase activity by dilution at subculture. This increase in activity occurred within 10 h of the dilution, whereas that produced by the hormones in the induction medium occurred after 120 h. The induction produced by dilution also occurred in these cells which had lost their ability to respond to the hormonal induction. Thus the mechanism that produced the increase in phenylalanine ammonia-lyase activity was intact but had lost its ability to respond to the hormones of the induction medium. The loss of inducibility was therefore probably not due to a genetic change in the cells brought about by continuous growth in a medium lacking coconut milk, but to reversible changes in the hormonal requirements of the cells necessary for induction.
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Claims 10
Claim · model-written summary
Repeated subculture in medium with only 2,4-dichlorophenoxyacetic acid progressively reduced phenylalanine ammonia-lyase activity and the number of induced xylem elements.
- Taxon
- Phaseolus vulgaris
Phaseolus vulgarist0 - Treatment
- 2,4-dichlorophenoxyacetic acide1
- Outcome
- phenylalanine ammonia-lyase activity and the number of xylem elements inducede2
- Direction
- progressively declinede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e1“in medium with only 2,4-dichlorophenoxyacetic acid for a period of 5--10 subcultures”
e2“the amounts of phenylalanine ammonia-lyase activity and the number of xylem elements induced progressively declined”
Claim · model-written summary
Cells grown with coconut milk did not lose their ability to induce phenylalanine ammonia-lyase or xylem elements, relative to the medium with only 2,4-dichlorophenoxyacetic acid.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Treatment
- coconut milke3
- Outcome
- ability to induce phenylalanine ammonia-lyase or xylem elementse3
- Direction
- did not losee3
- Comparator
- medium with only 2,4-dichlorophenoxyacetic acide1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e1“in medium with only 2,4-dichlorophenoxyacetic acid for a period of 5--10 subcultures”
e3“Cells grown in the presence of coconut milk did not lose the ability to induce phenylalanine ammonia-lyase or xylem elements”
Claim · model-written summary
Clones from cells grown with coconut milk differed in the amount of phenylalanine ammonia-lyase produced after induction.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Outcome
- producing different amounts of phenylalanine ammonia-lyasee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e4“Cells grown in the presence of coconut milk were cloned and clones capable of producing different amounts of phenylalanine ammonia-lyase when transferred to induction medium were obtained”
Claim · model-written summary
Clones producing low amounts of activity did not grow faster in the medium lacking coconut milk.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Treatment
- medium lacking coconut milke5
- Outcome
- clones producing low amounts of activitye5
- Direction
- did not grow fastere5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e5“clones producing low amounts of activity did not grow faster in the medium lacking coconut milk”
Claim · model-written summary
No evidence was found that selective growth of non-inducible cells caused the loss of morphogenetic potential.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Outcome
- loss of morphogenetic potentiale6
- Qualifier
- selective growth of non-inducible cellse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e6“no evidence was obtained to show that selective growth of non-inducible cells was responsible for the loss of morphogenetic potential”
Claim · model-written summary
Dilution at subculture stimulated phenylalanine ammonia-lyase activity in the cells.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Treatment
- dilution at subculturee7
- Outcome
- phenylalanine ammonia-lyase activitye7
- Direction
- stimulatede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e7“the cells could also be stimulated to produce phenylalanine ammonia-lyase activity by dilution at subculture”
Claim · model-written summary
The activity increase after dilution occurred within 10 h, whereas the hormone-induced increase occurred after 120 h.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Treatment
- dilutione0
- Outcome
- increase in activitye0
- Direction
- increasee0
- Value
- within 10 he0
- Qualifier
- after 120 he0
- Comparator
- the hormones in the induction mediume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e0“This increase in activity occurred within 10 h of the dilution, whereas that produced by the hormones in the induction medium occurred after 120 h”
Claim · model-written summary
Dilution-induced phenylalanine ammonia-lyase production also occurred in cells that had lost their response to hormonal induction.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Treatment
- dilutione1
- Outcome
- induction produced by dilutione1
- Direction
- also occurrede1
- Qualifier
- which had lost their ability to respond to the hormonal inductione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e1“The induction produced by dilution also occurred in these cells which had lost their ability to respond to the hormonal induction”
Claim · model-written summary
The mechanism producing the increase in phenylalanine ammonia-lyase activity was intact, but cells had lost their response to the induction-medium hormones.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Outcome
- increase in phenylalanine ammonia-lyase activitye2
- Qualifier
- lost its ability to respond to the hormones of the induction mediume2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e2“the mechanism that produced the increase in phenylalanine ammonia-lyase activity was intact but had lost its ability to respond to the hormones of the induction medium”
Claim · model-written summary
The loss of inducibility was probably due to reversible changes in the hormonal requirements of the cells, not to a genetic change.
- Taxon
- Phaseolus vulgarisPhaseolus vulgarist0
- Outcome
- loss of inducibilitye3
- Qualifier
- reversible changes in the hormonal requirements of the cellse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Phaseolus vulgaris”
e3“The loss of inducibility was therefore probably not due to a genetic change in the cells brought about by continuous growth in a medium lacking coconut milk, but to reversible changes in the hormonal requirements of the cells necessary for induction”
The same questions in other papers
2,4-D · physiology: antioxidant enzymes · Phaseolus vulgaris (common bean)Positive and negative results
2 in the opposite direction
- positive
- positive
in vitro · physiology: antioxidant enzymes · Phaseolus vulgaris (common bean)Results agree
1 paper in the same direction as this paper
- positive
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.