Abstract
Ralstonia solanacearum is an important pathogen causing bacterial wilt in pepper (Capsicum annuum L.). The concurrent infection of R. solanacearum and root-knot nematodes (Meloidogyne spp.) exacerbates the severity of bacterial wilt in pepper. Utilizing plant endophytic bacteria to control these mixed diseases is a viable strategy. Waltheria indica L. (Sterculiaceae) is a traditional medicine plant. A total of 209 endophytic bacteria were isolated from W. indica, and Pseudomonas aeruginosa W-126 showed an efficient antagonistic effect against R. solanacearum. Based on active compound tracking principles, a compound was isolated through silica gel column chromatography and preparative HPLC combined with TLC analysis. It was identified as phenazine-1-carboxamide (PCN) by spectral techniques (ESI-MS, 1H-NMR, 13C-NMR). PCN displayed excellent inhibitory activity against R. solanacearum, with an EC50 of 64.16 μg/mL in vitro. In addition, it showed certain nematocide activity, with an LC50 value of 118.63 μg/mL at 72 h. PCN also showed certain inhibitory activity against five other phytopathogenic bacteria. The structure−activity relationship indicated that the phenazine skeleton and acylamide groups were the key pharmacophores for the activity of phenazine-related compounds against R. solanacearum. PCN controlled the complex diseases of R. solanacearum and M. incognita in a pot experiment, with respective 51.41 and 39.80% inhibitory rates. The exploration of secondary metabolites of biocontrol bacteria can provide reference for the development of novel and efficient pesticides.
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Claims 9
Claim · model-written summary
Concurrent R. solanacearum and Meloidogyne infection worsened pepper bacterial wilt.
- Taxon
- peppere0
- Interactor
- R. solanacearum
Ralstonia solanacearume0pathogen - Second interactor
- Meloidogyne spp.
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Meloidogynee0pest - Outcome
- severity of bacterial wilte0
- Direction
- exacerbatese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_penetrates_a_tomato_root_-_USDA-ARS.jpg?width=500)
Verbatim
e0“The concurrent infection of R. solanacearum and root-knot nematodes (Meloidogyne spp.) exacerbates the severity of bacterial wilt in pepper”
Claim · model-written summary
P. aeruginosa W-126 from W. indica antagonized R. solanacearum.
- Taxon
- W. indica
Waltheria indicae1 - Interactor
- R. solanacearumRalstonia solanacearume0pathogen
- Second interactor
- Pseudomonas aeruginosa W-126
Pseudomonas aeruginosae0biocontrol_agent - Outcome
- antagonistic effect against R. solanacearume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pseudomonas aeruginosa W-126 showed an efficient antagonistic effect against R. solanacearum”
e1“A total of 209 endophytic bacteria were isolated from W. indica”
Claim · model-written summary
The active isolate compound was identified as phenazine-1-carboxamide.
- Taxon
- W. indicaWaltheria indicae1
- Interactor
- Pseudomonas aeruginosa W-126Pseudomonas aeruginosae2biocontrol_agente0
- Outcome
- identified as phenazine-1-carboxamidee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It was identified as phenazine-1-carboxamide (PCN) by spectral techniques”
t0“Pepper”
e1“A total of 209 endophytic bacteria were isolated from W. indica”
e2“Pseudomonas aeruginosa W-126 showed an efficient antagonistic effect against R. solanacearum”
Claim · model-written summary
PCN inhibited R. solanacearum in vitro with EC50 64.16 μg/mL.
- Taxon
- peppert0
- Interactor
- R. solanacearumRalstonia solanacearume0pathogen
- Outcome
- inhibitory activity against R. solanacearume0
- Value
- 64.16 μg/mLe0
- Setting
- in vitroe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PCN displayed excellent inhibitory activity against R. solanacearum, with an EC50 of 64.16 μg/mL in vitro”
t0“Pepper”
Claim · model-written summary
PCN had nematocidal activity with LC50 118.63 μg/mL at 72 h.
Not reportedInteractorInteractor role
Verbatim
e0“it showed certain nematocide activity, with an LC50 value of 118.63 μg/mL at 72 h”
t0“Pepper”
Claim · model-written summary
PCN inhibited five other phytopathogenic bacteria.
Verbatim
e0“PCN also showed certain inhibitory activity against five other phytopathogenic bacteria”
t0“Pepper”
Claim · model-written summary
Phenazine skeleton and acylamide groups were identified as key pharmacophores against R. solanacearum.
- Taxon
- peppert0
- Interactor
- R. solanacearumRalstonia solanacearume0pathogen
- Compound
- phenazine skeleton and acylamide groupse0
- Outcome
- activity of phenazine-related compounds against R. solanacearume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the phenazine skeleton and acylamide groups were the key pharmacophores for the activity of phenazine-related compounds against R. solanacearum”
t0“Pepper”
Claim · model-written summary
PCN controlled R. solanacearum disease in the pepper pot experiment with 51.41% inhibition.
- Taxon
- peppert0
- Treatment
- PCNe0
- Interactor
- R. solanacearumRalstonia solanacearume0pathogen
- Outcome
- complex diseases of R. solanacearum and M. incognitae0
- Direction
- controllede0
- Value
- 51.41e0
- Setting
- pot experimente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PCN controlled the complex diseases of R. solanacearum and M. incognita in a pot experiment, with respective 51.41 and 39.80% inhibitory rates”
t0“Pepper”
Claim · model-written summary
PCN controlled M. incognita disease in the pepper pot experiment with 39.80% inhibition.
- Taxon
- peppert0
- Treatment
- PCNe0
- Interactor
- M. incognitaMeloidogyne incognitae0pest
- Outcome
- complex diseases of R. solanacearum and M. incognitae0
- Direction
- controllede0
- Value
- 39.80%e0
- Setting
- pot experimente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PCN controlled the complex diseases of R. solanacearum and M. incognita in a pot experiment, with respective 51.41 and 39.80% inhibitory rates”
t0“Pepper”