Abstract
Blue light (BL) induces stomatal opening through the activation of H+-ATPases with subsequent ion accumulation in guard cells. In most plant species, red light (RL) enhances BL-dependent stomatal opening. This RL effect is attributable to the chloroplasts of guard cell, the only cells in the epidermis possessing this organelle. To clarify the role of chloroplasts in stomatal regulation, we investigated the effects of RL on BL-dependent stomatal opening in isolated epidermis, guard cell protoplasts, and intact leaves of Arabidopsis thaliana. In isolated epidermal tissues and intact leaves, weak BL superimposed on RL enhanced stomatal opening while BL alone was less effective. In guard cell protoplasts, RL enhanced BL-dependent H+-pumping and DCMU, a photosynthetic electron transport inhibitor, eliminated this effect. RL enhanced phosphorylation levels of the H+-ATPase in response to BL, but this RL effect was not suppressed by DCMU. Furthermore, DCMU inhibited both RL-induced and BL-dependent stomatal opening in intact leaves. The photosynthetic rate in leaves correlated positively with BL-dependent stomatal opening in the presence of DCMU. We conclude that guard cell chloroplasts provide ATP and/or reducing equivalents that fuel BL-dependent stomatal opening, and that they indirectly monitor photosynthetic CO2 fixation in mesophyll chloroplasts by absorbing PAR in the epidermis.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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
Weak blue light superimposed on red light enhanced stomatal opening in isolated epidermis and intact leaves relative to blue light alone.
- Taxon
- Arabidopsis thaliana
Arabidopsis thalianae1 - Organ / stage
- isolated epidermal tissues and intact leavese0
- Treatment
- weak BL superimposed on RLe0
- Outcome
- stomatal openinge0
- Direction
- enhancede0
- Comparator
- BL alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In isolated epidermal tissues and intact leaves, weak BL superimposed on RL enhanced stomatal opening while BL alone was less effective”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
Red light enhanced blue-light-dependent H+-pumping in guard-cell protoplasts.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Organ / stage
- guard cell protoplastse0
- Treatment
- RLe0
- Outcome
- BL-dependent H+-pumpinge0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In guard cell protoplasts, RL enhanced BL-dependent H+-pumping”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
DCMU eliminated the red-light enhancement of blue-light-dependent H+-pumping.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- DCMUe0
- Outcome
- RL enhanced BL-dependent H+-pumpinge0
- Direction
- eliminatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RL enhanced BL-dependent H+-pumping and DCMU, a photosynthetic electron transport inhibitor, eliminated this effect”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
Red light enhanced H+-ATPase phosphorylation in response to blue light.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- RLe0
- Gene
- H+-ATPasee0
- Outcome
- phosphorylation levels of the H+-ATPasee0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RL enhanced phosphorylation levels of the H+-ATPase in response to BL”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
DCMU did not suppress red-light enhancement of H+-ATPase phosphorylation.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Treatment
- DCMUe0
- Outcome
- RL effecte0
- Direction
- not suppressede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this RL effect was not suppressed by DCMU”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
DCMU inhibited red-light-induced stomatal opening in intact leaves.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Organ / stage
- intact leavese0
- Treatment
- DCMUe0
- Outcome
- RL-inducede0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DCMU inhibited both RL-induced and BL-dependent stomatal opening in intact leaves”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
DCMU inhibited blue-light-dependent stomatal opening in intact leaves.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Organ / stage
- intact leavese0
- Treatment
- DCMUe0
- Outcome
- BL-dependent stomatal openinge0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DCMU inhibited both RL-induced and BL-dependent stomatal opening in intact leaves”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
Leaf photosynthetic rate correlated positively with blue-light-dependent stomatal opening in the presence of DCMU.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Organ / stage
- leavese0
- Outcome
- BL-dependent stomatal openinge0
- Direction
- positivelye0
- Qualifier
- in the presence of DCMUe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The photosynthetic rate in leaves correlated positively with BL-dependent stomatal opening in the presence of DCMU”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
The authors conclude that guard cell chloroplasts supply ATP or reducing equivalents to fuel blue-light-dependent stomatal opening.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Organ / stage
- guard cell chloroplastse0
- Outcome
- BL-dependent stomatal openinge0
- Qualifier
- provide ATP and/or reducing equivalentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“guard cell chloroplasts provide ATP and/or reducing equivalents that fuel BL-dependent stomatal opening”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
Claim · model-written summary
The authors conclude that guard-cell chloroplasts indirectly monitor mesophyll photosynthetic CO2 fixation by absorbing PAR in the epidermis.
- Taxon
- Arabidopsis thalianaArabidopsis thalianae1
- Outcome
- photosynthetic CO2 fixation in mesophyll chloroplastse0
- Qualifier
- by absorbing PAR in the epidermise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“they indirectly monitor photosynthetic CO2 fixation in mesophyll chloroplasts by absorbing PAR in the epidermis”
t0“Arabidopsis”
e1“Arabidopsis thaliana”
The same questions in other papers
light · physiology: gas exchange · Arabidopsis thaliana (thale cress)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
2 papers more in this group
See all 6 papers →light · molecular: expression · Arabidopsis thaliana (thale cress)Positive and negative results
31 papers in the same direction as this paper · 15 in the opposite direction
- positive
- negative
- no effect
43 papers more in this group
See all 47 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.