Abstract
High nitrate (NO3−) in vegetables, especially in leaf vegetables poses threaten to human health. Selenium (Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies. Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses. However, the influence of exogenous Se on NO3− accumulation in hydroponic vegetables is still not clear. In the present study, hydroponic lettuce plants were subjected to six different concentrations (0, 0.1, 0.5, 5, 10 and 50 µmol L−1) of Se as Na2SeO3. The effects of Se on NO3− content, plant growth, and photosynthetic capacity of lettuce (Lactuca sativa L.) were investigated. The results showed that exogenous Se positively decreased NO3− content and this effect was concentration-dependent. The lowest NO3− content was obtained under 0.5 µmol L−1 Se treatment. The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate (Pn), stomatal conductance (Cs) and the transpiration efficiency (Tr) of lettuce. The transportation and assimilation of NO3− and activities of nitrogen metabolism enzymes in lettuce were also analysed. The NO3− efflux in the lettuce roots was markedly increased, but the efflux of NO3− from the root to the shoot was decreased after treated with exogenous Se. Moreover, Se application stimulated NO3− assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase enzyme (GOGAT) activities. These results provide direct evidence that exogenous Se shows positive function on decreasing NO3− accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce. We suggested that 0.5 µmol L−1 Se can be used to reduce NO3− content and increase hydroponic lettuce yield.
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Claims 8
Claim · model-written summary
Exogenous Se decreased nitrate content in a concentration-dependent manner.
- Taxon
- lettuce
Lactuca sativat0 - Treatment
- exogenous See0
- Outcome
- NO3− contente0
- Direction
- decreasede0
- Qualifier
- concentration-dependente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The results showed that exogenous Se positively decreased NO3− content and this effect was concentration-dependent.”
t0“lettuce”
Claim · model-written summary
The lowest nitrate content occurred at 0.5 µmol L−1 Se.
- Taxon
- lettuceLactuca sativat0
- Treatment
- 0.5 µmol L−1 Se treatmente0
- Outcome
- NO3− contente0
- Direction
- loweste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The lowest NO3− content was obtained under 0.5 µmol L−1 Se treatment.”
t0“lettuce”
Claim · model-written summary
Se increased photosynthesis rate, stomatal conductance and transpiration efficiency.
- Taxon
- lettuceLactuca sativae0
- Treatment
- application of See0
- Outcome
- photosynthesis rate (Pn), stomatal conductance (Cs) and the transpiration efficiency (Tr)e0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate (Pn), stomatal conductance (Cs) and the transpiration efficiency (Tr) of lettuce.”
Claim · model-written summary
Se increased nitrate efflux in lettuce roots.
- Taxon
- lettuceLactuca sativae0
- Treatment
- exogenous See0
- Outcome
- NO3− efflux in the lettuce rootse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The NO3− efflux in the lettuce roots was markedly increased, but the efflux of NO3− from the root to the shoot was decreased after treated with exogenous Se.”
Claim · model-written summary
Se decreased nitrate efflux from root to shoot.
- Taxon
- lettuceLactuca sativat0
- Treatment
- exogenous See0
- Outcome
- efflux of NO3− from the root to the shoote0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the efflux of NO3− from the root to the shoot was decreased after treated with exogenous Se.”
t0“lettuce”
Claim · model-written summary
Se increased nitrate reductase, nitrite reductase and glutamine synthetase activities.
- Taxon
- lettuceLactuca sativat0
- Treatment
- Se applicatione0
- Outcome
- nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS)e0
- Direction
- enhancinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Se application stimulated NO3− assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase enzyme (GOGAT) activities.”
t0“lettuce”
Claim · model-written summary
Se enhanced glutamate synthase enzyme activity.
- Taxon
- lettuceLactuca sativat0
- Treatment
- Se applicatione0
- Outcome
- glutamate synthase enzyme (GOGAT) activitiese0
- Direction
- enhancinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“lettuce”
e0“Se application stimulated NO3− assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase enzyme (GOGAT) activities.”
Claim · model-written summary
The authors recommend 0.5 µmol L−1 Se to reduce nitrate and increase hydroponic lettuce yield.
- Taxon
- lettuceLactuca sativae0
- Treatment
- 0.5 µmol L−1 See0
- Outcome
- reduce NO3− content and increase hydroponic lettuce yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We suggested that 0.5 µmol L−1 Se can be used to reduce NO3− content and increase hydroponic lettuce yield.”
The same questions in other papers
selenium atom · physiology: photosynthesis · Lactuca sativa (garden lettuce)Positive and negative results
2 in the opposite direction
- negative
- no effect
selenium atom · molecular: metabolites · Lactuca sativa (garden lettuce)Positive and negative results
6 papers in the same direction as this paper · 2 in the opposite direction · 1 reporting no difference from an alternative
- positive
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6 papers more in this group
See all 10 papers →selenium atom · physiology: enzyme activity · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- positive
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.