Abstract
Drought stress is one of the primary abiotic factors negatively affecting garlic growth, development, and yield formation. The application of plant growth-promoting bacteria (PGPB) could enhance plant tolerance to drought stress. The aim of this study was to explore the regulatory effect of the PGPB Pseudomonas sp. UW4 on growth and physiological indexes of garlic under drought stress. The results revealed that drought stresses significantly reduced total root length, total root surface area, root projection area and total root volume, chlorophyll content, antioxidant enzyme activity and osmolyte content (proline and soluble proteins), and increased relative electrical conductivity and malondialdehyde (MDA) content, all of which could be significantly improved by inoculating the roots with strain UW4. Under drought stress, an increase in total surface area of roots of 87.06% and an increase in root projected area of 40.71% were observed upon inoculation with strain UW4. The a, b, and total content of chlorophyll were increased significantly by 83.63%, 217.33% and 100.02%, respectively. The osmolyte content in leaves significantly increased, and decreased significantly in roots. The content of antioxidants also significantly increased. Moreover, the relative electrical conductivity in leaves and roots was decreased by 23.18% and 41.20%, respectively, upon strain UW4 inoculation. The content of malondialdehyde (MDA) was decreased by 25.23% and 54.08%, respectively, in the presence of strain UW4. The result of principal component analysis (PCA) revealed that the key factors influencing drought tolerance in garlic inoculated with Pseudomonas sp. UW4 could be summarized into two categories: photosynthetic pigments and root growth-related factors, and leaf osmotic adjustment and root antioxidant enzyme-related factors. Based on the result of the Mantel test, it can be inferred that there was a connection between the osmoregulation and antioxidant enzyme systems in the roots and leaves. Based on the D values, the comprehensive evaluation result of drought resistance was that the drought resistance of the garlic inoculated with strain UW4 under drought stress was lower than that of the garlic inoculated with UW4 under normal treatment and higher than that of the garlic under normal treatment. Therefore, Pseudomonas sp. UW4 enhanced the drought resistance of garlic seedlings by improving root phenotype and antioxidant enzyme activity, and increasing the content of shoot chlorophyll.
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Claims 20
Claim · model-written summary
Drought significantly reduced garlic root length, surface area, projection area and volume.
- Taxon
- garlic
Allium sativume1 - Treatment
- drought stressese0
- Outcome
- total root length, total root surface area, root projection area and total root volumee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought stresses significantly reduced total root length, total root surface area, root projection area and total root volume”
e1“garlic under drought stress”
Claim · model-written summary
Drought significantly reduced chlorophyll content.
- Taxon
- garlicAllium sativume1
- Treatment
- drought stressese0
- Outcome
- chlorophyll contente0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought stresses significantly reduced total root length, total root surface area, root projection area and total root volume, chlorophyll content”
e1“garlic under drought stress”
Claim · model-written summary
Drought significantly reduced antioxidant enzyme activity and osmolyte content.
- Taxon
- garlicAllium sativume1
- Treatment
- drought stressese0
- Outcome
- antioxidant enzyme activity and osmolyte content (proline and soluble proteins)e0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought stresses significantly reduced total root length, total root surface area, root projection area and total root volume, chlorophyll content, antioxidant enzyme activity and osmolyte content (proline and soluble proteins)”
e1“garlic under drought stress”
Claim · model-written summary
Drought increased electrical conductivity and MDA content.
- Taxon
- garlicAllium sativume2
- Treatment
- drought stressese1
- Outcome
- relative electrical conductivity and malondialdehyde (MDA) contente0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased relative electrical conductivity and malondialdehyde (MDA) content”
e1“drought stresses significantly reduced”
e2“garlic under drought stress”
Claim · model-written summary
UW4 inoculation improved the drought-affected parameters.
- Taxon
- garlicAllium sativume1
- Treatment
- inoculating the roots with strain UW4e0
- Interactor
- Pseudomonas sp. UW4
Pseudomonas sp. UW4e2symbiont - Outcome
- all of whiche0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all of which could be significantly improved by inoculating the roots with strain UW4”
e1“garlic under drought stress”
e2“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 raised root total surface area by 87.06% under drought.
- Taxon
- garlicAllium sativume1
- Treatment
- inoculation with strain UW4e0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e2symbiont
- Outcome
- total surface area of rootse0
- Direction
- increasee0
- Value
- 87.06%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under drought stress, an increase in total surface area of roots of 87.06% and an increase in root projected area of 40.71% were observed upon inoculation with strain UW4”
e1“garlic under drought stress”
e2“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 raised root projected area by 40.71% under drought.
- Taxon
- garlicAllium sativume1
- Treatment
- inoculation with strain UW4e0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e2symbiont
- Outcome
- root projected areae0
- Direction
- increasee0
- Value
- 40.71%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under drought stress, an increase in total surface area of roots of 87.06% and an increase in root projected area of 40.71% were observed upon inoculation with strain UW4”
e1“garlic under drought stress”
e2“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 significantly raised chlorophyll a by 83.63%.
- Taxon
- garlicAllium sativume2
- Treatment
- inoculation with strain UW4e1
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- ae0
- Direction
- increasede0
- Value
- 83.63%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The a, b, and total content of chlorophyll were increased significantly by 83.63%, 217.33% and 100.02%, respectively”
e1“inoculation with strain UW4”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 significantly raised chlorophyll b by 217.33%.
- Taxon
- garlicAllium sativume2
- Treatment
- inoculation with strain UW4e1
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- be0
- Direction
- increasede0
- Value
- 217.33%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The a, b, and total content of chlorophyll were increased significantly by 83.63%, 217.33% and 100.02%, respectively”
e1“inoculation with strain UW4”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 significantly raised total chlorophyll by 100.02%.
- Taxon
- garlicAllium sativume2
- Treatment
- inoculation with strain UW4e1
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- total content of chlorophylle0
- Direction
- increasede0
- Value
- 100.02%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The a, b, and total content of chlorophyll were increased significantly by 83.63%, 217.33% and 100.02%, respectively”
e1“inoculation with strain UW4”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
Leaf osmolyte content significantly increased with UW4.
- Taxon
- garlicAllium sativume2
- Treatment
- inoculation with strain UW4e1
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- osmolyte content in leavese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The osmolyte content in leaves significantly increased”
e1“inoculation with strain UW4”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
Root osmolyte content significantly decreased with UW4.
- Taxon
- garlicAllium sativume2
- Organ / stage
- rootse0
- Treatment
- inoculation with strain UW4e1
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- osmolyte contente0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The osmolyte content in leaves significantly increased, and decreased significantly in roots”
e1“inoculation with strain UW4”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
Antioxidant content significantly increased with UW4.
- Taxon
- garlicAllium sativume2
- Treatment
- inoculation with strain UW4e1
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- content of antioxidantse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The content of antioxidants also significantly increased”
e1“inoculation with strain UW4”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 reduced leaf relative electrical conductivity by 23.18%.
- Taxon
- garlicAllium sativume1
- Treatment
- strain UW4 inoculatione0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e2symbiont
- Outcome
- relative electrical conductivity in leavese0
- Direction
- decreasede0
- Value
- 23.18%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“relative electrical conductivity in leaves and roots was decreased by 23.18% and 41.20%, respectively, upon strain UW4 inoculation”
e1“garlic under drought stress”
e2“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 reduced root relative electrical conductivity by 41.20%.
- Taxon
- garlicAllium sativume1
- Organ / stage
- rootse0
- Treatment
- strain UW4 inoculatione0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e2symbiont
- Outcome
- relative electrical conductivitye0
- Direction
- decreasede0
- Value
- 41.20%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“relative electrical conductivity in leaves and roots was decreased by 23.18% and 41.20%, respectively, upon strain UW4 inoculation”
e1“garlic under drought stress”
e2“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 reduced leaf MDA content by 25.23%.
- Taxon
- garlicAllium sativume2
- Organ / stage
- leavese1
- Treatment
- strain UW4e0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- content of malondialdehyde (MDA)e0
- Direction
- decreasede0
- Value
- 25.23%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The content of malondialdehyde (MDA) was decreased by 25.23% and 54.08%, respectively, in the presence of strain UW4”
e1“relative electrical conductivity in leaves and roots”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
UW4 reduced root MDA content by 54.08%.
- Taxon
- garlicAllium sativume2
- Organ / stage
- rootse1
- Treatment
- strain UW4e0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e3symbiont
- Outcome
- content of malondialdehyde (MDA)e0
- Direction
- decreasede0
- Value
- 54.08%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The content of malondialdehyde (MDA) was decreased by 25.23% and 54.08%, respectively, in the presence of strain UW4”
e1“relative electrical conductivity in leaves and roots”
e2“garlic under drought stress”
e3“PGPB Pseudomonas sp. UW4”
Claim · model-written summary
PCA grouped drought-tolerance factors into photosynthetic/root-growth and leaf-osmotic/root-antioxidant categories.
- Taxon
- garlicAllium sativume0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e0symbiont
- Outcome
- drought tolerancee0
- Qualifier
- photosynthetic pigments and root growth-related factors, and leaf osmotic adjustment and root antioxidant enzyme-related factorse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“key factors influencing drought tolerance in garlic inoculated with Pseudomonas sp. UW4 could be summarized into two categories: photosynthetic pigments and root growth-related factors, and leaf osmotic adjustment and root antioxidant enzyme-related factors”
Claim · model-written summary
Mantel testing suggested a connection between root and leaf osmoregulation and antioxidant systems.
- Taxon
- garlicAllium sativume1
- Organ / stage
- roots and leavese0
- Outcome
- connection between the osmoregulation and antioxidant enzyme systemse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was a connection between the osmoregulation and antioxidant enzyme systems in the roots and leaves”
e1“garlic under drought stress”
Claim · model-written summary
D-value evaluation ranked drought resistance of UW4-inoculated stressed garlic below UW4-inoculated normal garlic and above uninoculated normal garlic.
- Taxon
- garlicAllium sativume0
- Treatment
- inoculated with strain UW4 under drought stresse0
- Interactor
- Pseudomonas sp. UW4Pseudomonas sp. UW4e1symbiont
- Outcome
- drought resistancee0
- Direction
- lower thane0
- Qualifier
- higher than that of the garlic under normal treatmente0
- Comparator
- garlic inoculated with UW4 under normal treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the drought resistance of the garlic inoculated with strain UW4 under drought stress was lower than that of the garlic inoculated with UW4 under normal treatment and higher than that of the garlic under normal treatment”
e1“PGPB Pseudomonas sp. UW4”
The same questions in other papers
drought · growth · Allium sativum (garlic)Results differ
4 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
2 papers more in this group
See all 6 papers →drought · physiology: pigments · Allium sativum (garlic)Results agree
1 paper in the same direction as this paper
- negative
inoculation · Pseudomonas sp. UW4 · Allium sativum (garlic)Results agree
1 paper in the same direction as this paper
- positive
drought · physiology: oxidative · Allium sativum (garlic)Results agree
2 papers in the same direction as this paper
- negative
- negative
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.