Abstract
The widespread presence of polycyclic aromatic hydrocarbons (PAHs) and toxic heavy metals in soils is having harmful effects on food crops and the environment. However, the defense mechanisms and capacity of plants to counteract these substances have not been comprehensively explored, necessitating a systematic categorization of their inhibitory effects. Accordingly, an experimental investigation was conducted to examine the growth and physiological response of maize ( Zea mays L.) to different concentrations and combinations of pyrene, copper (Cu), and cadmium (Cd), with an indicator developed to assess the joint stress. The results showed that 57-day culture with contaminations significantly inhibited the plant biomass via causing root cell necrosis, inducing lipid peroxidation, and damaging photosynthesis. Cd (50-100 mg/kg) induced stronger inhibition than Cu (800-1000 mg/kg) under both single and joint stress, and their co-existence further aggravated the adverse effects and generated synergetic inhibition. Although the presence of pyrene at a low concentration (5-50 mg/kg) can somewhat diminish the metal stress, the elevated pollutant concentrations (400-750 mg/kg pyrene, 50-100 mg/kg Cd, and 800-1000 mg/kg Cu) switched the antagonistic effect to additive inhibition on maize growth. A satisfactory tolerance of a low-level pyrene and/or metal stress was determined, associated with a relative stability of chlorophyll-a (Chl-a) content and antioxidant enzymes activity. Nevertheless, the photosynthesis and antioxidant system were significantly damaged with increasing contaminant concentrations, resulting in chlorosis and biomass reduction. These findings could provide valuable knowledge for ensuring crop yield and food quality as well as implementing soil phytoremediation.
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Claims 11
Claim · model-written summary
Contamination inhibited maize biomass.
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“57-day culture with contaminations significantly inhibited the plant biomass”
e1“maize ( Zea mays L.)”
Claim · model-written summary
Contamination caused root cell necrosis.
- Outcome
- root cell necrosise0
Not reportedTreatmentComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“causing root cell necrosis”
e1“maize ( Zea mays L.)”
Claim · model-written summary
Contamination induced lipid peroxidation.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“inducing lipid peroxidation”
e1“57-day culture with contaminations significantly inhibited the plant biomass”
e2“maize ( Zea mays L.)”
Claim · model-written summary
Contamination damaged photosynthesis.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“damaging photosynthesis”
e1“57-day culture with contaminations significantly inhibited the plant biomass”
e2“maize ( Zea mays L.)”
Claim · model-written summary
Cadmium inhibited maize more strongly than copper.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cd (50-100 mg/kg) induced stronger inhibition than Cu (800-1000 mg/kg) under both single and joint stress”
e1“maize ( Zea mays L.)”
Claim · model-written summary
Coexisting cadmium and copper aggravated adverse effects synergistically.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“their co-existence further aggravated the adverse effects and generated synergetic inhibition”
e1“Cd (50-100 mg/kg) induced stronger inhibition than Cu (800-1000 mg/kg)”
e2“maize ( Zea mays L.)”
Claim · model-written summary
Low pyrene somewhat diminished metal stress.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“pyrene at a low concentration (5-50 mg/kg) can somewhat diminish the metal stress”
e1“maize ( Zea mays L.)”
Claim · model-written summary
Elevated pollutant concentrations produced additive inhibition of maize growth.
- Treatment
- elevated pollutant concentrations (400-750 mg/kg pyrene, 50-100 mg/kg Cd, and 800-1000 mg/kg Cu)e0
- Outcome
- maize growthe0
- Direction
- inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the elevated pollutant concentrations (400-750 mg/kg pyrene, 50-100 mg/kg Cd, and 800-1000 mg/kg Cu) switched the antagonistic effect to additive inhibition on maize growth”
Claim · model-written summary
Low contaminant stress was tolerated with relatively stable chlorophyll-a and antioxidant activity.
- Outcome
- chlorophyll-a (Chl-a) content and antioxidant enzymes activitye0
- Direction
- relative stabilitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A satisfactory tolerance of a low-level pyrene and/or metal stress was determined, associated with a relative stability of chlorophyll-a (Chl-a) content and antioxidant enzymes activity.”
e1“maize ( Zea mays L.)”
Claim · model-written summary
Increasing contaminants damaged photosynthesis and antioxidant systems.
- Treatment
- increasing contaminant concentrationse0
- Outcome
- photosynthesis and antioxidant systeme0
- Direction
- damagede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the photosynthesis and antioxidant system were significantly damaged with increasing contaminant concentrations”
e1“maize ( Zea mays L.)”
Claim · model-written summary
Increasing contaminants led to chlorosis and biomass reduction.
- Treatment
- increasing contaminant concentrationse1
- Outcome
- chlorosis and biomass reductione0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulting in chlorosis and biomass reduction”
e1“increasing contaminant concentrations”
e2“maize ( Zea mays L.)”
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