Abstract
During the cold season, low temperature (LT) and high relative humidity (HRH) are significant environmental factors in greenhouses and plastic tunnels, often hindering plant growth and development. The chlorophyll (Chl) biosynthesis inhibitory mechanisms under LT and HRH stress are still widely unclear. To understand how cucumbers seedlings respond to LT and HRH stress, we investigated the impact of these stressors on Chl biosynthesis. Our results revealed that individual LT, HRH and combined LT + HRH stress conditions affected chlorophyll a , b , total chlorophyll and carotenoid content, reducing the levels of these pigments. The levels of Chlorophyll precursors were also markedly reduced under LT and HRH stresses, with the greatest reduction observed in cucumber seedlings exposed to LT + HRH conditions (9/5℃, 95%HRH). The activities of glutamate-1-semialdehyde transaminase (GSA-AT), ALA dehydratase (ALAD), Mg-chelatase, and protochlorophyllide oxidoreductase (POR) were increased under individual LT, HRH, conditions but decreased by combination of LT + HRH stress condition. In addition, Chl biosynthesis related genes (except PBG) were upregulated by the HRH stress but were significantly downregulated under the LT + HRH stress condition in cucumber seedlings. Furthermore, the content of phenols, flavonoids and phenolic acids (cinnamic acid and caffeic acid) were significantly surged under LT + HRH treatment over the control. Histochemical observation showed higher O 2 − and H 2 O 2 content in cucumber leaves during the LT and HRH stress. The results indicate that LT + HRH stress significantly impairs chlorophyll biosynthesis in cucumber seedlings by drastically reducing pigment accumulation, altering enzyme activity and gene expression. Additionally, LT + HRH stress induces oxidative damage, which further exacerbates the decline in chlorophyll content and affects overall cucumber metabolism.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. 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 9
Claim · model-written summary
Individual and combined low temperature and high humidity reduced chlorophyll a, chlorophyll b and total chlorophyll.
- Taxon
- cucumber
Cucumis sativust0 - Treatment
- individual LT, HRH and combined LT + HRH stress conditionse0
- Outcome
- chlorophyll a , b , total chlorophylle0
- Direction
- reducinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“individual LT, HRH and combined LT + HRH stress conditions affected chlorophyll a , b , total chlorophyll and carotenoid content, reducing the levels of these pigments.”
t0“Cucumber”
Claim · model-written summary
Individual and combined stress reduced carotenoid content.
- Taxon
- cucumberCucumis sativust0
- Treatment
- individual LT, HRH and combined LT + HRH stress conditionse0
- Outcome
- carotenoid contente0
- Direction
- reducinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“individual LT, HRH and combined LT + HRH stress conditions affected chlorophyll a , b , total chlorophyll and carotenoid content, reducing the levels of these pigments.”
t0“Cucumber”
Claim · model-written summary
Low temperature and high humidity reduced chlorophyll precursors, most under combined stress.
- Taxon
- cucumber seedlingsCucumis sativuse0
- Treatment
- LT + HRH conditions (9/5℃, 95%HRH)e0
- Outcome
- Chlorophyll precursorse0
- Direction
- reducede0
- Qualifier
- greatest reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The levels of Chlorophyll precursors were also markedly reduced under LT and HRH stresses, with the greatest reduction observed in cucumber seedlings exposed to LT + HRH conditions (9/5℃, 95%HRH).”
Claim · model-written summary
Individual LT and HRH increased four chlorophyll biosynthesis enzyme activities.
- Taxon
- CucumberCucumis sativust0
- Treatment
- individual LT, HRH, conditionse0
- Outcome
- activities of glutamate-1-semialdehyde transaminase (GSA-AT), ALA dehydratase (ALAD), Mg-chelatase, and protochlorophyllide oxidoreductase (POR)e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The activities of glutamate-1-semialdehyde transaminase (GSA-AT), ALA dehydratase (ALAD), Mg-chelatase, and protochlorophyllide oxidoreductase (POR) were increased under individual LT, HRH, conditions”
t0“Cucumber”
Claim · model-written summary
Combined LT and HRH decreased those four enzyme activities.
- Taxon
- CucumberCucumis sativust0
- Treatment
- combination of LT + HRH stress conditione0
- Outcome
- activities of glutamate-1-semialdehyde transaminase (GSA-AT), ALA dehydratase (ALAD), Mg-chelatase, and protochlorophyllide oxidoreductase (POR)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The activities of glutamate-1-semialdehyde transaminase (GSA-AT), ALA dehydratase (ALAD), Mg-chelatase, and protochlorophyllide oxidoreductase (POR) were increased under individual LT, HRH, conditions but decreased by combination of LT + HRH stress condition.”
t0“Cucumber”
Claim · model-written summary
HRH increased expression of chlorophyll biosynthesis genes except PBG.
- Taxon
- CucumberCucumis sativust0
- Treatment
- HRH stresse0
- Outcome
- Chl biosynthesis related genes (except PBG)e0
- Direction
- upregulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chl biosynthesis related genes (except PBG) were upregulated by the HRH stress”
t0“Cucumber”
Claim · model-written summary
Combined LT and HRH significantly decreased expression of chlorophyll biosynthesis genes.
- Taxon
- cucumber seedlingsCucumis sativuse0
- Treatment
- LT + HRH stress conditione0
- Outcome
- downregulatede0
- Direction
- downregulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“were significantly downregulated under the LT + HRH stress condition in cucumber seedlings.”
Claim · model-written summary
Combined stress significantly increased phenols, flavonoids and phenolic acids.
- Taxon
- CucumberCucumis sativust0
- Treatment
- LT + HRH treatmente0
- Outcome
- content of phenols, flavonoids and phenolic acids (cinnamic acid and caffeic acid)e0
- Direction
- surgede0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the content of phenols, flavonoids and phenolic acids (cinnamic acid and caffeic acid) were significantly surged under LT + HRH treatment over the control.”
t0“Cucumber”
Claim · model-written summary
LT and HRH increased O2− and H2O2 in cucumber leaves.
- Taxon
- cucumberCucumis sativuse0
- Organ / stage
- leavese0
- Treatment
- LT and HRH stresse0
- Outcome
- O 2 − and H 2 O 2 contente0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Histochemical observation showed higher O 2 − and H 2 O 2 content in cucumber leaves during the LT and HRH stress.”
The same questions in other papers
humidity · physiology: oxidative · Cucumis sativus (cucumber)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- negative
cold · molecular: expression · Cucumis sativus (cucumber)Positive and negative results
4 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
4 papers more in this group
See all 8 papers →cold · physiology: pigments · Cucumis sativus (cucumber)Positive and negative results
7 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- negative
5 papers more in this group
See all 9 papers →cold · molecular: metabolites · Cucumis sativus (cucumber)Positive and negative results
6 papers in the same direction as this paper · 6 in the opposite direction
- positive
- positive
- positive
9 papers more in this group
See all 13 papers →cold · physiology: oxidative · Cucumis sativus (cucumber)Positive and negative results
17 papers in the same direction as this paper · 3 in the opposite direction
- negative
- positive
- positive
17 papers more in this group
See all 21 papers →humidity · physiology: pigments · Cucumis sativus (cucumber)Results agree
1 paper in the same direction as this paper
- negative
humidity · molecular: expression · Cucumis sativus (cucumber)Results agree
1 paper in the same direction as this paper
- negative
humidity · molecular: metabolites · Cucumis sativus (cucumber)Results agree
2 papers in the same direction as this paper
- negative
- no effect
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.