Abstract
Photosynthetic efficiency decreases as light energy surpasses the photosynthesis capacity. This study was designed to investigate the potential effects of high-intensity light on the photooxidation-prone mutant 812HS of rice and its wild-type 812S during yellow and recovering stages. Results showed that in the yellowing stage, light oxidation occurs due to the exposure of mutant 812HS leaves to the high sunlight, which causes yellowing of the leaves, leading to a reduction in the photochemical activities, physiological mechanisms, and protein contents in mutant 812HS. In the recovery stage, mutant 812HS leaves were exposed to the maximum high brightness, the mutant’s leaves were draped with a dark cover to decrease the exposure of leaves of the plants from direct sunlight, which leads to the restoration of the green color again to the mutant 812HS leaves, leading to improving the performance of the photochemical activities, physiological mechanisms, and protein contents in mutant 812HS. Exposing leaves of mutant 812HS to high light at the yellow stage also resulted in a decrease in the net photosynthetic rate (Pn) in carotenoids content and chlorophyll a and b. Similarly, chlorophyll fluorescence of mutant 812HS decreased in (O-I-J-I-P) curves, and the ATP content, Mg2+-ATPase, and Ca2+-ATPase activities also decreased. An increase in energy dissipation was observed, while ABS/RC, DI0/RC, and TR0/RC values in mutant 812HS at the yellow stage increased. During photooxidation, an increase in O2•– and H2O2 contents was observed in mutant 812HS. While O2•– and H2O2 contents were decreased in mutant 812HS at the recovery stage. The rate of thylakoid membrane protein content was significantly decreased in mutant 812HS at the yellow stage, while at the recovery stage, there was no significant decrease. Our findings showed that photooxidation prompted oxidative damages and lipid peroxidation that caused severe damages to the membranes of the cell, photosynthetic pigments degradation, protein levels, and photosynthesis inhibition in mutant 812HS.
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Claims 14
Claim · model-written summary
High sunlight caused leaf yellowing in mutant 812HS.
- Taxon
- Rice
Oryza sativat0 - Material
- 812HSt0
- Outcome
- yellowing of the leavese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“light oxidation occurs due to the exposure of mutant 812HS leaves to the high sunlight, which causes yellowing of the leaves”
t0“Rice Mutant 812HS”
Claim · model-written summary
High light reduced photochemical activities, physiological mechanisms and protein contents in yellowing mutant leaves.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- photochemical activities, physiological mechanisms, and protein contentse0
- Direction
- reductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leading to a reduction in the photochemical activities, physiological mechanisms, and protein contents in mutant 812HS”
t0“Rice Mutant 812HS”
Claim · model-written summary
Dark cover restored green leaf color in mutant 812HS.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Treatment
- draped with a dark covere0
- Outcome
- restoration of the green colore0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mutant’s leaves were draped with a dark cover to decrease the exposure of leaves of the plants from direct sunlight, which leads to the restoration of the green color again to the mutant 812HS leaves”
t0“Rice Mutant 812HS”
Claim · model-written summary
Recovery improved photochemical activities, physiological mechanisms and protein contents.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- photochemical activities, physiological mechanisms, and protein contentse0
- Direction
- improvinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leading to improving the performance of the photochemical activities, physiological mechanisms, and protein contents in mutant 812HS”
t0“Rice Mutant 812HS”
Claim · model-written summary
High light at the yellow stage decreased net photosynthetic rate, carotenoids and chlorophyll a and b.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- net photosynthetic rate (Pn) in carotenoids content and chlorophyll a and be0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exposing leaves of mutant 812HS to high light at the yellow stage also resulted in a decrease in the net photosynthetic rate (Pn) in carotenoids content and chlorophyll a and b”
t0“Rice Mutant 812HS”
Claim · model-written summary
Chlorophyll fluorescence decreased in mutant 812HS.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- chlorophyll fluorescencee0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chlorophyll fluorescence of mutant 812HS decreased in (O-I-J-I-P) curves”
t0“Rice Mutant 812HS”
Claim · model-written summary
ATP content and Mg2+-ATPase and Ca2+-ATPase activities decreased.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- ATP content, Mg2+-ATPase, and Ca2+-ATPase activitiese0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the ATP content, Mg2+-ATPase, and Ca2+-ATPase activities also decreased”
t0“Rice Mutant 812HS”
Claim · model-written summary
Energy dissipation increased.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- energy dissipatione0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“An increase in energy dissipation was observed”
t0“Rice Mutant 812HS”
Claim · model-written summary
ABS/RC, DI0/RC and TR0/RC increased at the yellow stage.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- ABS/RC, DI0/RC, and TR0/RC valuese0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ABS/RC, DI0/RC, and TR0/RC values in mutant 812HS at the yellow stage increased”
t0“Rice Mutant 812HS”
Claim · model-written summary
O2•– and H2O2 content increased during photooxidation.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- O2•– and H2O2 contentse0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During photooxidation, an increase in O2•– and H2O2 contents was observed in mutant 812HS”
t0“Rice Mutant 812HS”
Claim · model-written summary
O2•– and H2O2 content decreased during recovery.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- O2•– and H2O2 contentse0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“O2•– and H2O2 contents were decreased in mutant 812HS at the recovery stage”
t0“Rice Mutant 812HS”
Claim · model-written summary
Thylakoid membrane protein content significantly decreased at the yellow stage.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- thylakoid membrane protein contente0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rate of thylakoid membrane protein content was significantly decreased in mutant 812HS at the yellow stage”
t0“Rice Mutant 812HS”
Claim · model-written summary
At recovery, thylakoid membrane protein content showed no significant decrease.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- thylakoid membrane protein contente0
- Direction
- no significant decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rate of thylakoid membrane protein content was significantly decreased in mutant 812HS at the yellow stage, while at the recovery stage, there was no significant decrease”
t0“Rice Mutant 812HS”
Claim · model-written summary
Photooxidation caused oxidative damage, lipid peroxidation, membrane damage, pigment degradation, lower protein levels and photosynthesis inhibition.
- Taxon
- RiceOryza sativat0
- Material
- 812HSt0
- Outcome
- oxidative damages and lipid peroxidatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“photooxidation prompted oxidative damages and lipid peroxidation that caused severe damages to the membranes of the cell, photosynthetic pigments degradation, protein levels, and photosynthesis inhibition in mutant 812HS”
t0“Rice Mutant 812HS”