Abstract
Limited data are available on the effects of 5-aminolevulinic acid (ALA) on plant photosynthesis in relation to the nitrogen (N) level. In this study, we investigate photosynthetic responses to ALA in canola plants (Brassica napus L.). We used wild-type plants without ALA addition (controls), wild-type plants with exogenous ALA application, and transgenic plants that endogenously overproduced ALA. The plants were grown hydroponically in nutrient solutions with low, middle, and high concentrations of N. Our results indicate that plants in both treatment groups had higher chlorophyll contents and net photosynthetic rates and lower intracellular CO2 concentrations in the leaves, as compared to controls. Furthermore, simultaneous measurement of prompt chlorophyll fluorescence and modulated 820-nm reflections showed that the active photosystem II (PS II) reaction centers, electron transfer capacity, and photosystem I (PS I) activity were all higher in treated plants than controls at all N levels; however, the responses of some photochemical processes to ALA were significantly affected by the N level. For example, under low N conditions only, a negative ΔK peak appeared in the prompt chlorophyll fluorescence curve, indicating a protective effect of ALA on electron donation via activation of the oxygen-evolving complex. Taken together, our findings suggest that ALA contributes to the promotion of photosynthesis by regulating photosynthetic electron transport under various N levels. These findings may provide a new strategy for improving photosynthesis in crops grown in N-poor conditions or reduced N-fertilization requirements.
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Claims 8
Claim · model-written summary
Exogenous ALA increased leaf chlorophyll content and net photosynthetic rate.
- Taxon
- canola
.jpg?width=60)
Brassica napus var. napuse2 - Organ / stage
- leavese0
- Treatment
- exogenous ALA applicatione1
- Outcome
- chlorophyll contents and net photosynthetic ratese0
- Direction
- highere0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“plants in both treatment groups had higher chlorophyll contents and net photosynthetic rates and lower intracellular CO2 concentrations in the leaves, as compared to controls.”
e1“wild-type plants with exogenous ALA application”
e2“canola plants (Brassica napus L.)”
Claim · model-written summary
Endogenous ALA overproduction increased leaf chlorophyll content and net photosynthetic rate.
- Taxon
- canolaBrassica napus var. napuse2
- Organ / stage
- leavese0
- Treatment
- endogenously overproduced ALAe1
- Outcome
- chlorophyll contents and net photosynthetic ratese0
- Direction
- highere0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plants in both treatment groups had higher chlorophyll contents and net photosynthetic rates and lower intracellular CO2 concentrations in the leaves, as compared to controls.”
e1“transgenic plants that endogenously overproduced ALA”
e2“canola plants (Brassica napus L.)”
Claim · model-written summary
Exogenous ALA reduced intracellular leaf CO2 concentration.
- Taxon
- canolaBrassica napus var. napuse2
- Organ / stage
- leavese0
- Treatment
- exogenous ALA applicatione1
- Outcome
- intracellular CO2 concentrationse0
- Direction
- lowere0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plants in both treatment groups had higher chlorophyll contents and net photosynthetic rates and lower intracellular CO2 concentrations in the leaves, as compared to controls.”
e1“wild-type plants with exogenous ALA application”
e2“canola plants (Brassica napus L.)”
Claim · model-written summary
Endogenous ALA overproduction reduced intracellular leaf CO2 concentration.
- Taxon
- canolaBrassica napus var. napuse2
- Organ / stage
- leavese0
- Treatment
- endogenously overproduced ALAe1
- Outcome
- intracellular CO2 concentrationse0
- Direction
- lowere0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plants in both treatment groups had higher chlorophyll contents and net photosynthetic rates and lower intracellular CO2 concentrations in the leaves, as compared to controls.”
e1“transgenic plants that endogenously overproduced ALA”
e2“canola plants (Brassica napus L.)”
Claim · model-written summary
Exogenous ALA increased active PS II centers, electron transfer capacity and PS I activity at all nitrogen levels.
- Taxon
- canolaBrassica napus var. napuse2
- Treatment
- exogenous ALA applicatione1
- Outcome
- active photosystem II (PS II) reaction centers, electron transfer capacity, and photosystem I (PS I) activitye0
- Direction
- highere0
- Qualifier
- at all N levelse0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the active photosystem II (PS II) reaction centers, electron transfer capacity, and photosystem I (PS I) activity were all higher in treated plants than controls at all N levels”
e1“wild-type plants with exogenous ALA application”
e2“canola plants (Brassica napus L.)”
Claim · model-written summary
Endogenous ALA overproduction increased active PS II centers, electron transfer capacity and PS I activity at all nitrogen levels.
- Taxon
- canolaBrassica napus var. napuse2
- Treatment
- endogenously overproduced ALAe1
- Outcome
- active photosystem II (PS II) reaction centers, electron transfer capacity, and photosystem I (PS I) activitye0
- Direction
- highere0
- Qualifier
- at all N levelse0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the active photosystem II (PS II) reaction centers, electron transfer capacity, and photosystem I (PS I) activity were all higher in treated plants than controls at all N levels”
e1“transgenic plants that endogenously overproduced ALA”
e2“canola plants (Brassica napus L.)”
Claim · model-written summary
Nitrogen level significantly affected some photochemical responses to ALA.
- Taxon
- canolaBrassica napus var. napuse1
- Treatment
- N levele0
- Outcome
- responses of some photochemical processes to ALAe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the responses of some photochemical processes to ALA were significantly affected by the N level”
e1“canola plants (Brassica napus L.)”
Claim · model-written summary
A negative fluorescence ΔK peak appeared only under low nitrogen with ALA.
- Taxon
- canolaBrassica napus var. napuse1
- Outcome
- a negative ΔK peak appeared in the prompt chlorophyll fluorescence curvee0
- Qualifier
- under low N conditions onlye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under low N conditions only, a negative ΔK peak appeared in the prompt chlorophyll fluorescence curve”
e1“canola plants (Brassica napus L.)”
The same questions in other papers
5-aminolevulinic acid · physiology: photosynthesis · Brassica napus (oilseed rape)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
5-aminolevulinic acid · molecular: metabolites · Brassica napus (oilseed rape)Results agree
5 papers in the same direction as this paper
- positive
- positive
- positive
2 papers more in this group
See all 6 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.