Abstract
Copper (Cu) is a micronutrient that assumes a principal role in plant growth and development. However, its excess concentration in soil is imperiling crop productivity. Inoculation with different bacterial strains in cereals could modify growth traits, photosynthetic effectiveness, and generation of strong antioxidant defense systems to make them more tolerant of Cu stress. Therefore, a pot study was designed to test plant growth-promoting rhizobacteria (PGPR) including Paenibacillus polymyxa and Bacillus circulans to Cu exposed maize (Zea mays L.) plants. Increasing Cu (100 to 500 µM of CuSO4) concentration decreased growth traits, photosynthetic pigments, soluble sugars, phosphorous (P) and potassium (K) contents, and the activity of catalase (CAT) but increased proline and malondialdehyde (MDA) content, the activity of peroxidase (POD) and Cu ions at root and shoot level. Moreover, the bacterial treatment also modulated the antioxidant capability in stress-free plants. Nevertheless, inoculation with P. polymyxa and B. circulans alleviated Cu-induced growth, photosynthetic pigments and mineral nutrient (P and K) on one hand and regulating the pools of osmolytes and antioxidant enzymes, whilst simultaneously reducing MDA and Cu root and shoot contents. These improved activities of antioxidant enzymes and the regulation of osmolytes content elicited by the blend of bacterial inoculation would have retained the ability of maize plants to confer resilience to Cu stress. This study further affirms that the application of two specific bacterial strains to maize plants proved very effective to ameliorate the Cu toxicity.
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Claims 12
Claim · model-written summary
Increasing copper lowered maize growth traits.
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing Cu (100 to 500 µM of CuSO4) concentration decreased growth traits, photosynthetic pigments, soluble sugars, phosphorous (P) and potassium (K) contents, and the activity of catalase (CAT)”
e1“maize (Zea mays L.)”
Claim · model-written summary
Increasing copper lowered photosynthetic pigments and soluble sugars.
- Treatment
- Cu (100 to 500 µM of CuSO4)e0
- Outcome
- photosynthetic pigments, soluble sugarse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing Cu (100 to 500 µM of CuSO4) concentration decreased growth traits, photosynthetic pigments, soluble sugars, phosphorous (P) and potassium (K) contents, and the activity of catalase (CAT)”
e1“maize (Zea mays L.)”
Claim · model-written summary
Increasing copper lowered phosphorus and potassium contents.
- Treatment
- Cu (100 to 500 µM of CuSO4)e0
- Outcome
- phosphorous (P) and potassium (K) contentse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing Cu (100 to 500 µM of CuSO4) concentration decreased growth traits, photosynthetic pigments, soluble sugars, phosphorous (P) and potassium (K) contents, and the activity of catalase (CAT)”
e1“maize (Zea mays L.)”
Claim · model-written summary
Increasing copper lowered catalase activity.
- Treatment
- Cu (100 to 500 µM of CuSO4)e0
- Gene
- catalase (CAT)e0
- Outcome
- activity of catalase (CAT)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing Cu (100 to 500 µM of CuSO4) concentration decreased growth traits, photosynthetic pigments, soluble sugars, phosphorous (P) and potassium (K) contents, and the activity of catalase (CAT)”
e1“maize (Zea mays L.)”
Claim · model-written summary
Increasing copper raised proline and MDA content.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased proline and malondialdehyde (MDA) content, the activity of peroxidase (POD) and Cu ions at root and shoot level.”
t0“Copper Stress in Maize”
Claim · model-written summary
Increasing copper raised peroxidase activity.
- Treatment
- Copper Stresst0
- Gene
- peroxidase (POD)e0
- Outcome
- activity of peroxidase (POD)e0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased proline and malondialdehyde (MDA) content, the activity of peroxidase (POD) and Cu ions at root and shoot level.”
t0“Copper Stress in Maize”
Claim · model-written summary
Increasing copper raised copper ions in roots and shoots.
- Organ / stage
- root and shoote0
- Treatment
- Copper Stresst0
- Outcome
- Cu ions at root and shoot levele0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased proline and malondialdehyde (MDA) content, the activity of peroxidase (POD) and Cu ions at root and shoot level.”
t0“Copper Stress in Maize”
Claim · model-written summary
Bacterial treatment modulated antioxidants in plants without stress.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the bacterial treatment also modulated the antioxidant capability in stress-free plants.”
t0“Maize”
Claim · model-written summary
Inoculation alleviated copper-induced impairment of growth, pigments and P and K nutrition.
- Treatment
- inoculation with P. polymyxa and B. circulanse0
- Interactor
- P. polymyxa
Paenibacillus polymyxae0symbiont - Second interactor
- B. circulanse0symbiont
- Outcome
- Cu-induced growth, photosynthetic pigments and mineral nutrient (P and K)e0
- Direction
- alleviatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“inoculation with P. polymyxa and B. circulans alleviated Cu-induced growth, photosynthetic pigments and mineral nutrient (P and K)”
t0“Maize”
Claim · model-written summary
Inoculation regulated osmolyte pools and antioxidant enzymes.
- Treatment
- Inoculation with Paenibacillus polymyxa and Bacillus circulanst0
- Interactor
- Paenibacillus polymyxaPaenibacillus polymyxat0symbiont
- Second interactor
- Bacillus circulanst0symbiont
- Outcome
- pools of osmolytes and antioxidant enzymese0
- Direction
- regulatinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“regulating the pools of osmolytes and antioxidant enzymes”
t0“Mitigation of Copper Stress in Maize by Inoculation with Paenibacillus polymyxa and Bacillus circulans”
Claim · model-written summary
Inoculation reduced MDA and copper contents in roots and shoots.
- Organ / stage
- root and shoote0
- Treatment
- Inoculation with Paenibacillus polymyxa and Bacillus circulanst0
- Interactor
- Paenibacillus polymyxaPaenibacillus polymyxat0symbiont
- Second interactor
- Bacillus circulanst0symbiont
- Outcome
- MDA and Cu root and shoot contentse0
- Direction
- reducinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“simultaneously reducing MDA and Cu root and shoot contents.”
t0“Mitigation of Copper Stress in Maize by Inoculation with Paenibacillus polymyxa and Bacillus circulans”
Claim · model-written summary
The authors interpret antioxidant and osmolyte changes as contributing to copper resilience.
- Treatment
- blend of bacterial inoculatione0
- Outcome
- resilience to Cu stresse0
- Qualifier
- improved activities of antioxidant enzymes and the regulation of osmolytes contente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These improved activities of antioxidant enzymes and the regulation of osmolytes content elicited by the blend of bacterial inoculation would have retained the ability of maize plants to confer resilience to Cu stress.”
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See all 53 papers →8 of 10 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
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.