Abstract
To avoid metal toxicity, plants have developed mechanisms including efflux of metal ions from cells and their sequestration into cellular compartments. In this report, we present evidence for the role of plasma membrane efflux systems in metal tolerance of cucumber roots. We have identified the plasma membrane‐transport system participating in Cd, Pb, Mn and Ni efflux from the cytosol. Kinetic characterization of this proton‐coupled transport system revealed that it is saturable and has a different affinity for each of the metal ions used (with Km 5, 7.5 and 0.1 m M for Mn, Ni and Pb, respectively). Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles. After decreasing the metal concentration to 50 μ M we still observed a large increase (over 150%) of this activity in comparison with the control. Moreover, the addition of 50 μ M Cd to the external solution stimulated not only Cd antiport in the plasmalemma vesicles but also the antiport of other metals used in the experiments. Treatment of cucumber roots with 50 μ M Ni revealed a similar effect: the antiport activity of Cd, Mn, Ni and Pb was stimulated, although to a lesser extent in comparison with stimulation by Cd. The data indicate that the root plasma membrane antiporter system is stimulated by the exogenous presence of heavy metals.
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 10
Claim · model-written summary
A plasma membrane system exports Cd, Pb, Mn and Ni from cucumber root cytosol.
- Taxon
- cucumber
Cucumis sativust0 - Organ / stage
- rootst0
- Outcome
- Cd, Pb, Mn and Ni efflux from the cytosole0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We have identified the plasma membrane‐transport system participating in Cd, Pb, Mn and Ni efflux from the cytosol.”
t0“cucumber roots”
t1“cucumber roots”
Claim · model-written summary
The proton-coupled transport system is saturable.
- Taxon
- cucumberCucumis sativust0
- Outcome
- saturablee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kinetic characterization of this proton‐coupled transport system revealed that it is saturable”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
The transport system has a Mn Km of 5 m M.
- Taxon
- cucumberCucumis sativust0
- Compound
- Mne0
- Outcome
- Kme0
- Value
- 5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with Km 5, 7.5 and 0.1 m M for Mn, Ni and Pb, respectively”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
The transport system has a Ni Km of 7.5 m M.
- Taxon
- cucumberCucumis sativust0
- Compound
- Nie0
- Outcome
- Kme0
- Value
- 7.5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with Km 5, 7.5 and 0.1 m M for Mn, Ni and Pb, respectively”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
The transport system has a Pb Km of 0.1 m M.
- Taxon
- cucumberCucumis sativust0
- Compound
- Pbe0
- Outcome
- Kme0
- Value
- 0.1 m Me0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with Km 5, 7.5 and 0.1 m M for Mn, Ni and Pb, respectively”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
Pretreatment with 100 μ M Cd increased cucumber root Cd antiport activity by over 250%.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- rootse0
- Treatment
- 100 μ M Cde0
- Outcome
- Cd antiport activitye0
- Direction
- increasee0
- Value
- over 250%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
At 50 μ M Cd, Cd antiport activity increased by over 150% versus control.
- Taxon
- cucumberCucumis sativust0
- Treatment
- 50 μ Me0
- Outcome
- Cd antiport activityt1
- Direction
- increasee0
- Value
- over 150%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After decreasing the metal concentration to 50 μ M we still observed a large increase (over 150%) of this activity in comparison with the control.”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
External 50 μ M Cd stimulated Cd antiport and antiport of other tested metals.
- Taxon
- cucumberCucumis sativust0
- Treatment
- 50 μ M Cde0
- Outcome
- Cd antiport in the plasmalemma vesiclese0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the addition of 50 μ M Cd to the external solution stimulated not only Cd antiport in the plasmalemma vesicles but also the antiport of other metals used in the experiments.”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
External Cd stimulated antiport of other tested metals.
- Taxon
- cucumberCucumis sativust0
- Treatment
- 50 μ M Cde0
- Outcome
- antiport of other metalse0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the addition of 50 μ M Cd to the external solution stimulated not only Cd antiport in the plasmalemma vesicles but also the antiport of other metals used in the experiments.”
t0“cucumber”
t1“Treatment of cucumber roots with 100 μ M Cd prior to the transport measurements caused a great increase (over 250%) in Cd antiport activity in plasmalemma vesicles.”
Claim · model-written summary
Ni treatment stimulated antiport of Cd, Mn, Ni and Pb less than Cd treatment.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- rootse0
- Treatment
- 50 μ M Nie0
- Outcome
- antiport activity of Cd, Mn, Ni and Pbe0
- Direction
- stimulatede0
- Comparator
- stimulation by Cde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment of cucumber roots with 50 μ M Ni revealed a similar effect: the antiport activity of Cd, Mn, Ni and Pb was stimulated, although to a lesser extent in comparison with stimulation by Cd.”
The same questions in other papers
nickel atom · nutrient: content · Cucumis sativus (cucumber)Positive and negative results
3 in the opposite direction
- negative
- no effect
- no effect
cadmium atom · nutrient: content · Cucumis sativus (cucumber)Positive and negative results
1 paper in the same direction as this paper · 6 in the opposite direction
- no effect
- negative
- negative
4 papers more in this group
See all 8 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.