Abstract
Calcium (Ca(2+)) signals regulate many aspects of plant development, including a programmed cell death pathway that protects plants from pathogens (hypersensitive response). Cytosolic Ca(2+) signals result from a combined action of Ca(2+) influx through channels and Ca(2+) efflux through pumps and cotransporters. Plants utilize calmodulin-activated Ca(2+) pumps (autoinhibited Ca(2+)-ATPase [ACA]) at the plasma membrane, endoplasmic reticulum, and vacuole. Here, we show that a double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11 in Arabidopsis (Arabidopsis thaliana) results in a high frequency of hypersensitive response-like lesions. The appearance of macrolesions could be suppressed by growing plants with increased levels (greater than 15 mm) of various anions, providing a method for conditional suppression. By removing plants from a conditional suppression, lesion initials were found to originate primarily in leaf mesophyll cells, as detected by aniline blue staining. Initiation and spread of lesions could also be suppressed by disrupting the production or accumulation of salicylic acid (SA), as shown by combining aca4/11 mutations with a sid 2 (for salicylic acid induction-deficient2) mutation or expression of the SA degradation enzyme NahG. This indicates that the loss of the vacuolar Ca(2+) pumps by itself does not cause a catastrophic defect in ion homeostasis but rather potentiates the activation of a SA-dependent programmed cell death pathway. Together, these results provide evidence linking the activity of the vacuolar Ca(2+) pumps to the control of a SA-dependent programmed cell death pathway in plants.
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Claims 5
Claim · model-written summary
A double knockout of the vacuolar Ca2+ pumps ACA4 and ACA11 in Arabidopsis thaliana results in a high frequency of hypersensitive response-like lesions.
- Taxon
- Arabidopsis thaliana
Arabidopsis thalianae1 - Treatment
- double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11e1
- Outcome
- hypersensitive response-like lesionse1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“a double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11 in Arabidopsis (Arabidopsis thaliana) results in a high frequency of hypersensitive response-like lesions”
Claim · model-written summary
Lesion initials arise mainly in leaf mesophyll cells.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Organ / stage
- leaf mesophyll cellse2
- Outcome
- lesion initialse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“lesion initials were found to originate primarily in leaf mesophyll cells”
e1“a double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11 in Arabidopsis (Arabidopsis thaliana)”
Claim · model-written summary
Macrolesions could be suppressed by growing plants with more than 15 mm of various anions.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- growing plants with increased levels (greater than 15 mm) of various anionse3
- Outcome
- appearance of macrolesionse3
- Direction
- suppressede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“The appearance of macrolesions could be suppressed by growing plants with increased levels (greater than 15 mm) of various anions”
e1“a double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11 in Arabidopsis (Arabidopsis thaliana)”
Claim · model-written summary
Lesion initiation and spread were suppressed by disrupting salicylic acid production or accumulation.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- disrupting the production or accumulation of salicylic acid (SA)e4
- Compound
- salicylic acide4
- Outcome
- Initiation and spread of lesionse4
- Direction
- suppressede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Initiation and spread of lesions could also be suppressed by disrupting the production or accumulation of salicylic acid (SA)”
e1“a double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11 in Arabidopsis (Arabidopsis thaliana)”
Claim · model-written summary
Loss of the vacuolar Ca2+ pumps potentiates activation of an SA-dependent programmed cell death pathway rather than causing a catastrophic ion homeostasis defect.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Compound
- SAe5
- Outcome
- activation of a SA-dependent programmed cell death pathwaye5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“the loss of the vacuolar Ca(2+) pumps by itself does not cause a catastrophic defect in ion homeostasis but rather potentiates the activation of a SA-dependent programmed cell death pathway”
e1“a double knockout mutation of the vacuolar Ca(2+) pumps ACA4 and ACA11 in Arabidopsis (Arabidopsis thaliana)”
The same questions in other papers
salicylic acid · disease · Arabidopsis thaliana (thale cress)Positive and negative results
10 papers in the same direction as this paper · 5 in the opposite direction
- no effect
- negative
- negative
12 papers more in this group
See all 16 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.