Abstract
Abstract In an attempt to elucidate the underlying mechanisms for iron toxicity in plants, the combined effects of iron overload and light intensities on the photosynthetic capacity of leaves were particularly focussed upon in this study, using mung bean seedlings grown under varied conditions regarding the supply of light and iron. The seedlings, when supplied with excess iron (up to 1.0 m M ) and low light (40 W/m 2 ), did not suffer any loss of photosynthesis; further, the typical symptoms of iron toxicity, as shown in the leaves grown in sunlight at ca 450 W/m 2 on an average, were not seen in those. Nonetheless, excess iron supply resulted in a marked increase in photosensitivity of the low light‐adapted seedlings. A large portion of iron accumulated in chloroplasts by the supply of excess iron was found to be incorporated into thylakoids as nonheme iron (NHI), which acts as a potent sensitizer, photogenerating singlet oxygen ( 1 O 2 ). The generation rate of 1 O 2 from thylakoids linearly increased with increasing content of NHI; this was in parallel with the NHI content dependence of photoinactivation rates of photosynthetic electron transport and key enzymes of the Calvin cycle in chloroplasts. The results suggest that Fe‐dependent photosensitization reactions, occurring via the 1 O 2 mechanism, may be deeply involved in cellular processes leading to developing iron toxicity symptoms in plants.
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 8
Claim · model-written summary
Excess iron under low light did not cause loss of photosynthesis in mung bean seedlings.
- Taxon
- MUNG BEAN
.jpg?width=60)
Vigna radiatat0 - Treatment
- excess iron (up to 1.0 m M ) and low light (40 W/m 2 )e0
- Outcome
- photosynthesise0
- Direction
- did not suffer any losse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“The seedlings, when supplied with excess iron (up to 1.0 m M ) and low light (40 W/m 2 ), did not suffer any loss of photosynthesis”
t0“MUNG BEAN”
Claim · model-written summary
Iron toxicity symptoms seen in sunlight-grown leaves were absent in low-light-grown seedlings supplied with excess iron.
- Taxon
- MUNG BEANVigna radiatat0
- Treatment
- excess iron (up to 1.0 m M ) and low light (40 W/m 2 )e1
- Outcome
- symptoms of iron toxicitye0
- Direction
- were not seene0
- Comparator
- leaves grown in sunlight at ca 450 W/m 2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the typical symptoms of iron toxicity, as shown in the leaves grown in sunlight at ca 450 W/m 2 on an average, were not seen in those”
e1“The seedlings, when supplied with excess iron (up to 1.0 m M ) and low light (40 W/m 2 )”
t0“MUNG BEAN”
Claim · model-written summary
Excess iron markedly increased photosensitivity of low-light-adapted mung bean seedlings.
- Taxon
- MUNG BEANVigna radiatat0
- Treatment
- excess iron supplye0
- Outcome
- photosensitivitye0
- Direction
- marked increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“excess iron supply resulted in a marked increase in photosensitivity of the low light‐adapted seedlings”
t0“MUNG BEAN”
Claim · model-written summary
A large portion of iron accumulated in chloroplasts after excess iron supply was incorporated into thylakoids as nonheme iron.
- Taxon
- MUNG BEANVigna radiatat0
- Organ / stage
- thylakoidse0
- Treatment
- supply of excess irone0
- Outcome
- iron accumulated in chloroplastse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A large portion of iron accumulated in chloroplasts by the supply of excess iron was found to be incorporated into thylakoids as nonheme iron (NHI)”
t0“MUNG BEAN”
Claim · model-written summary
Singlet oxygen generation from thylakoids increased linearly with nonheme iron content.
- Taxon
- MUNG BEANVigna radiatat0
- Compound
- NHIe0
- Outcome
- generation rate of 1 O 2e0
- Direction
- linearly increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The generation rate of 1 O 2 from thylakoids linearly increased with increasing content of NHI”
t0“MUNG BEAN”
Claim · model-written summary
Photosynthetic electron transport photoinactivation rates depended on nonheme iron content.
- Taxon
- MUNG BEANVigna radiatat0
- Compound
- NHIe0
- Outcome
- photoinactivation rates of photosynthetic electron transporte0
- Direction
- content dependencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NHI content dependence of photoinactivation rates of photosynthetic electron transport and key enzymes of the Calvin cycle in chloroplasts”
t0“MUNG BEAN”
Claim · model-written summary
Photoinactivation rates of key Calvin cycle enzymes depended on nonheme iron content.
- Taxon
- MUNG BEANVigna radiatat0
- Compound
- NHIe0
- Outcome
- photoinactivation rates of photosynthetic electron transport and key enzymes of the Calvin cyclee0
- Direction
- content dependencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NHI content dependence of photoinactivation rates of photosynthetic electron transport and key enzymes of the Calvin cycle in chloroplasts”
t0“MUNG BEAN”
Claim · model-written summary
The authors suggest iron-dependent photosensitization via singlet oxygen may contribute to iron toxicity symptoms.
- Taxon
- MUNG BEANVigna radiatat0
- Outcome
- iron toxicity symptomse0
- Qualifier
- Fe‐dependent photosensitization reactions, occurring via the 1 O 2 mechanisme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fe‐dependent photosensitization reactions, occurring via the 1 O 2 mechanism, may be deeply involved in cellular processes leading to developing iron toxicity symptoms in plants”
t0“MUNG BEAN”
The same questions in other papers
iron atom · physiology: photosynthesis · Vigna radiata (mung bean)Positive and negative results
1 in the opposite direction
- positive
light · physiology: photosynthesis · Vigna radiata (mung bean)Positive and negative results
1 in the opposite direction
- positive
light · disease · Vigna radiata (mung bean)Positive and negative results
4 papers in the same direction as this paper · 1 in the opposite direction
- negative
- 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.