Abstract
BACKGROUND: The production of high-quality crops based on phytochemicals is a strategy for accelerating the practical use of plant factories. Previous studies have demonstrated that ultraviolet (UV) light is effective in improving phytochemical production. This study aimed to determine the effect of various UV wavelengths on growth and phenolic compound accumulation in lettuce (Lactuca sativa L.) grown in a closed-type plant production system. RESULTS: Seven days, 1 day and 0.25 day were determined as the upper limit of the irradiation periods for UV-A, -B, and -C, respectively, in the lettuce based on physiological disorders and the fluorescence parameter F(v)/F(m). Continuous UV-A treatment significantly induced the accumulation of phenolic compounds and antioxidants until 4 days of treatment without growth inhibition, consistent with an increase in phenylalanine ammonia lyase (PAL) gene expression and PAL activity. Repeated or gradual UV-B exposure yielded approximately 1.4-3.6 times more total phenolics and antioxidants, respectively, than the controls did 2 days after the treatments, although both treatments inhibited lettuce growth. Repeated UV-C exposure increased phenolics but severely inhibited the growth of lettuce plants. CONCLUSION: Our data suggest that UV irradiation can improve the accumulation of phenolic compounds with antioxidant properties in lettuce cultivated in plant factories.
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
Continuous UV-A treatment significantly induced accumulation of phenolic compounds and antioxidants in lettuce until 4 days of treatment.
- Taxon
- lettuce
Lactuca sativae0 - Treatment
- Continuous UV-A treatmente1
- Outcome
- accumulation of phenolic compounds and antioxidantse1
- Direction
- inducede1
- Qualifier
- until 4 days of treatmente1
- Setting
- closed-type plant production systeme0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e1“Continuous UV-A treatment significantly induced the accumulation of phenolic compounds and antioxidants until 4 days of treatment without growth inhibition”
Claim · model-written summary
Continuous UV-A treatment did not inhibit lettuce growth up to 4 days of treatment.
- Taxon
- lettuceLactuca sativae0
- Treatment
- Continuous UV-A treatmente1
- Outcome
- growthe1
- Direction
- without growth inhibitione1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e1“Continuous UV-A treatment significantly induced the accumulation of phenolic compounds and antioxidants until 4 days of treatment without growth inhibition”
Claim · model-written summary
UV-A treatment increased phenylalanine ammonia lyase gene expression and PAL activity in lettuce.
- Taxon
- lettuceLactuca sativae0
- Gene
- phenylalanine ammonia lyase (PAL)e2
- Outcome
- gene expression and PAL activitye2
- Direction
- increasee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e2“consistent with an increase in phenylalanine ammonia lyase (PAL) gene expression and PAL activity”
Claim · model-written summary
Repeated or gradual UV-B exposure yielded about 1.4-3.6 times more total phenolics and antioxidants than controls 2 days after treatment.
- Taxon
- lettuceLactuca sativae0
- Treatment
- Repeated or gradual UV-B exposuree3
- Outcome
- total phenolics and antioxidantse3
- Direction
- moree3
- Value
- approximately 1.4-3.6 timese3
- Qualifier
- 2 days after the treatmentse3
- Comparator
- the controlse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e3“Repeated or gradual UV-B exposure yielded approximately 1.4-3.6 times more total phenolics and antioxidants, respectively, than the controls did 2 days after the treatments”
Claim · model-written summary
Repeated or gradual UV-B exposure inhibited lettuce growth.
- Taxon
- lettuceLactuca sativae0
- Treatment
- Repeated or gradual UV-B exposuree3
- Outcome
- lettuce growthe4
- Direction
- inhibitede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e3“Repeated or gradual UV-B exposure yielded approximately 1.4-3.6 times more total phenolics and antioxidants, respectively, than the controls did 2 days after the treatments”
e4“although both treatments inhibited lettuce growth”
Claim · model-written summary
Repeated UV-C exposure increased phenolics in lettuce.
- Taxon
- lettuceLactuca sativae0
- Treatment
- Repeated UV-C exposuree5
- Outcome
- phenolicse5
- Direction
- increasede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e5“Repeated UV-C exposure increased phenolics but severely inhibited the growth of lettuce plants”
Claim · model-written summary
Repeated UV-C exposure severely inhibited the growth of lettuce plants.
- Taxon
- lettuceLactuca sativae0
- Treatment
- Repeated UV-C exposuree5
- Outcome
- growth of lettuce plantse5
- Direction
- severely inhibitede5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in lettuce (Lactuca sativa L.) grown in a closed-type plant production system”
e5“Repeated UV-C exposure increased phenolics but severely inhibited the growth of lettuce plants”
Claim · model-written summary
Upper limits of irradiation periods in lettuce were 7 days for UV-A, 1 day for UV-B and 0.25 day for UV-C.
- Taxon
- lettuceLactuca sativae6
- Outcome
- upper limit of the irradiation periodse6
- Value
- Seven days, 1 day and 0.25 daye6
- Qualifier
- based on physiological disorders and the fluorescence parameter F(v)/F(m)e6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“Seven days, 1 day and 0.25 day were determined as the upper limit of the irradiation periods for UV-A, -B, and -C, respectively, in the lettuce based on physiological disorders and the fluorescence parameter F(v)/F(m)”
The same questions in other papers
uv · quality: phytochemicals · Lactuca sativa (garden lettuce)Results differ
23 papers in the same direction as this paper · 4 in the opposite direction
- negative
- positive
- positive
24 papers more in this group
See all 28 papers →uv · growth · Lactuca sativa (garden lettuce)Results differ
19 papers in the same direction as this paper · 15 in the opposite direction
- positive
- negative
- no effect
31 papers more in this group
See all 35 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.