Abstract
Due to the continuous production of industrial wastes and the excessive use of chemical fertilizers and pesticides, severe cadmium (Cd) pollution in soil has occurred globally. This study investigated the impacts of incorporating zinc oxide nanoparticles (ZnONPs) into hydroponically grown lettuce ( Lactuca sativa ) under cadmium stress conditions, to seek effective methods to minimize Cd buildup in green leafy vegetables . The results showed that 1 mg/L of Cd significantly inhibited lettuce growth, decreasing in leaves (29 %) and roots (33 %) biomass. However, when lettuce was exposed to 2.5 mg/L ZnONPs under cadmium stress, the growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesis were all significantly enhanced. Furthermore, ZnONPs significantly decreased the accumulation of Cd in lettuce leaves (36 %) and roots (13 %). They altered the subcellular distribution and chemical morphology of Cd in lettuce by modifying the composition of cell walls (such as pectin content) and the levels of phenolic compounds, resulting in a reduction of 27 % in Cd translocation from roots to leaves. RNA sequencing yielded 45.9 × 10 7 and 53.4 × 10 7 clean reads from plant leaves and roots in control (T0), Cd (T1), Cd+ZnONPs (T2), and ZnONPs (T3) treatment groups respectively, and 3614 and 1873 differentially expressed genes (DEGs) were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified photosynthesis , carbon fixation , and phenylpropanoid metabolism as the main causes of ZnONPs-mediated alleviation of Cd stress in lettuce. Specifically, the DEGs identified included 12 associated with photosystem I , 13 with photosystem II and 23 DEGs with the carbon fixation pathway of photosynthesis. Additionally, DEGs related to phenylalanine ammonia-lyase, caffeoyl CoA 3-O-methyltransferase, peroxidase , 4-coumarate-CoA ligase , hydroxycinnamoyl transferase , and cytochrome P450 proteins were also identified. Therefore, further research is recommended to elucidate the molecular mechanisms by which ZnONPs reduce Cd absorption in lettuce through phenolic acid components in the phenylpropanoid metabolism pathway. Overall, treatments with ZnONPs are recommended to effectively reduce Cd accumulation in the edible portion of lettuce.
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 19
Claim · model-written summary
Cd decreased lettuce leaf biomass by 29%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“1 mg/L of Cd significantly inhibited lettuce growth, decreasing in leaves (29 %) and roots (33 %) biomass”
t0“lettuce”
Claim · model-written summary
Cd decreased lettuce root biomass by 33%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“1 mg/L of Cd significantly inhibited lettuce growth, decreasing in leaves (29 %) and roots (33 %) biomass”
t0“lettuce”
Claim · model-written summary
ZnONPs under Cd stress increased lettuce growth.
- Taxon
- lettuce
Lactuca sativae0 - Treatment
- 2.5 mg/L ZnONPs under cadmium stresse0
- Outcome
- growthe0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when lettuce was exposed to 2.5 mg/L ZnONPs under cadmium stress, the growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesis were all significantly enhanced”
Claim · model-written summary
ZnONPs under Cd stress enhanced chlorophyll content, net photosynthetic rate and stomatal conductance.
- Taxon
- lettuceLactuca sativae0
- Treatment
- 2.5 mg/L ZnONPs under cadmium stresse0
- Outcome
- chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs)e0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when lettuce was exposed to 2.5 mg/L ZnONPs under cadmium stress, the growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesis were all significantly enhanced”
Claim · model-written summary
ZnONPs under Cd stress enhanced PSII efficiency and photosynthetic enzyme activity.
- Taxon
- lettuceLactuca sativae0
- Treatment
- 2.5 mg/L ZnONPs under cadmium stresse0
- Outcome
- actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesise0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when lettuce was exposed to 2.5 mg/L ZnONPs under cadmium stress, the growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesis were all significantly enhanced”
Claim · model-written summary
ZnONPs decreased Cd accumulation in lettuce leaves by 36%.
- Taxon
- lettuceLactuca sativae0
- Treatment
- ZnONPse0
- Outcome
- accumulation of Cd in lettuce leavese0
- Direction
- decreasede0
- Value
- 36 %e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ZnONPs significantly decreased the accumulation of Cd in lettuce leaves (36 %) and roots (13 %)”
Claim · model-written summary
ZnONPs decreased Cd accumulation in lettuce roots by 13%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ZnONPs significantly decreased the accumulation of Cd in lettuce leaves (36 %) and roots (13 %)”
Claim · model-written summary
ZnONPs reduced Cd translocation from roots to leaves by 27%.
- Taxon
- lettuceLactuca sativae0
- Treatment
- ZnONPse0
- Outcome
- Cd translocation from roots to leavese0
- Direction
- reductione0
- Value
- 27 %e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ZnONPs significantly decreased the accumulation of Cd in lettuce leaves (36 %) and roots (13 %). They altered the subcellular distribution and chemical morphology of Cd in lettuce by modifying the composition of cell walls (such as pectin content) and the levels of phenolic compounds, resulting in a reduction of 27 % in Cd translocation from roots to leaves”
Claim · model-written summary
ZnONPs altered subcellular Cd distribution and chemical form through cell wall and phenolic changes.
- Taxon
- lettuceLactuca sativae0
- Outcome
- subcellular distribution and chemical morphology of Cd in lettucee0
- Qualifier
- modifying the composition of cell walls (such as pectin content) and the levels of phenolic compoundse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“They altered the subcellular distribution and chemical morphology of Cd in lettuce by modifying the composition of cell walls (such as pectin content) and the levels of phenolic compounds”
Claim · model-written summary
RNA sequencing yielded 45.9 × 10 7 clean reads from leaves.
- Taxon
- lettuceLactuca sativat0
- Outcome
- clean reads from plant leavese0
- Value
- 45.9 × 10 7e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RNA sequencing yielded 45.9 × 10 7 and 53.4 × 10 7 clean reads from plant leaves and roots”
t0“lettuce”
Claim · model-written summary
RNA sequencing yielded 53.4 × 10 7 clean reads from roots.
- Taxon
- lettuceLactuca sativat0
- Outcome
- plant leaves and rootse0
- Value
- 53.4 × 10 7e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“RNA sequencing yielded 45.9 × 10 7 and 53.4 × 10 7 clean reads from plant leaves and roots”
t0“lettuce”
Claim · model-written summary
The analysis identified 3614 differentially expressed genes in leaves.
- Taxon
- lettuceLactuca sativat0
- Outcome
- differentially expressed genes (DEGs)e0
- Value
- 3614e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“3614 and 1873 differentially expressed genes (DEGs) were identified”
t0“lettuce”
Claim · model-written summary
The analysis identified 1873 differentially expressed genes in roots.
- Taxon
- lettuceLactuca sativat0
- Outcome
- differentially expressed genes (DEGs)e0
- Value
- 1873e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“3614 and 1873 differentially expressed genes (DEGs) were identified”
t0“lettuce”
Claim · model-written summary
KEGG analysis implicated photosynthesis, carbon fixation and phenylpropanoid metabolism in Cd stress alleviation.
- Taxon
- lettuceLactuca sativae0
- Outcome
- ZnONPs-mediated alleviation of Cd stress in lettucee0
- Qualifier
- photosynthesis , carbon fixation , and phenylpropanoid metabolisme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified photosynthesis , carbon fixation , and phenylpropanoid metabolism as the main causes of ZnONPs-mediated alleviation of Cd stress in lettuce.”
Claim · model-written summary
Twelve DEGs were associated with photosystem I.
- Taxon
- lettuceLactuca sativat0
- Outcome
- associated with photosystem Ie0
- Value
- 12e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“12 associated with photosystem I”
t0“lettuce”
Claim · model-written summary
Thirteen DEGs were associated with photosystem II.
- Taxon
- lettuceLactuca sativat0
- Outcome
- photosystem IIe0
- Value
- 13e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“13 with photosystem II”
t0“lettuce”
Claim · model-written summary
Twenty-three DEGs were associated with carbon fixation.
- Taxon
- lettuceLactuca sativat0
- Outcome
- DEGs with the carbon fixation pathway of photosynthesise0
- Value
- 23e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“23 DEGs with the carbon fixation pathway of photosynthesis”
t0“lettuce”
Claim · model-written summary
DEGs related to six phenylpropanoid pathway proteins were identified.
- Taxon
- lettuceLactuca sativat0
- Outcome
- DEGs related to phenylalanine ammonia-lyase, caffeoyl CoA 3-O-methyltransferase, peroxidase , 4-coumarate-CoA ligase , hydroxycinnamoyl transferase , and cytochrome P450 proteinse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DEGs related to phenylalanine ammonia-lyase, caffeoyl CoA 3-O-methyltransferase, peroxidase , 4-coumarate-CoA ligase , hydroxycinnamoyl transferase , and cytochrome P450 proteins were also identified.”
t0“lettuce”
Claim · model-written summary
The authors recommend ZnONP treatment to reduce Cd accumulation in edible lettuce.
- Taxon
- lettuceLactuca sativae0
- Treatment
- treatments with ZnONPse0
- Outcome
- reduce Cd accumulation in the edible portion of lettucee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Overall, treatments with ZnONPs are recommended to effectively reduce Cd accumulation in the edible portion of lettuce.”
The same questions in other papers
cadmium atom · growth · Lactuca sativa (garden lettuce)Results differ
16 papers in the same direction as this paper · 3 in the opposite direction
- negative
- positive
- positive
16 papers more in this group
See all 20 papers →zinc oxide nanoparticle · growth · Lactuca sativa (garden lettuce)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- positive
- no effect
- positive
zinc oxide nanoparticle · physiology: photosynthesis · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- positive
zinc oxide nanoparticle · molecular: metabolites · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- positive
zinc oxide nanoparticle · nutrient: content · Lactuca sativa (garden lettuce)Results agree
3 papers in the same direction as this paper
- positive
- positive
- positive
heavy metal · physiology: photosynthesis · Lactuca sativa (garden lettuce)Positive and negative results
3 in the opposite direction
- negative
- negative
- negative
heavy metal · growth · Lactuca sativa (garden lettuce)Positive and negative results
13 in the opposite direction
- negative
- negative
- negative
10 papers more in this group
See all 14 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.