Abstract
Studies on pectolytic enzymes secreted by Pseudomonas marginalis were conducted to elucidate a specific dissolution of pectic substances in infected host cell walls.Two isolates of pathogenic bacteria, N-6122 and N-6301, secreted pectic acid trans-eliminase (PATE), when grown on pectin-asparagine medium. Pectin esterase (PE) activity was extremely weak in culture filtrates. As for N-6301, the dialyzed filtrate also had a strong pectin trans-eliminase (PTE) activity, which reacts specifically to methylated pectin. In addition, weak polygalacturonase (PG) activity was found in this preparation. In the case of N-6122, these enzyme activities were not detected. From these results, it is concluded that polyuronide-chain spliting enzyme system in N-6122 obviously differs from N-6301.PATE and PTE showed maximum reaction velocity at pH8.3 in Sørensen borate buffer systems, when pectin was used as a substrate. PATE activity was remarkably accelerated by addition of 10-3M CaCl2, and completely inhibited by 10-4M EDTA, using sodium-polypectate as a substrate. PTE activity was not apparently affected by these chemical compounds.Dialyzed culture filtrate of N-6122, mainly containing PATE, showed typical action to degradate plant tissues. When maceration activity was measured by per cent loss in dry weight of radish, the preparation indicated an ability to decrease about 12% of sliced tissues, after incubation at 30C for 8 hours. The physical properties of tissuemacerating agent in dialyzed filtrate were similar to those of PATE. They responded in the same way to pH and temperature, viz, inactivation by lower or higher pH value and heating. From these reasons, it can be said that the tissue degradation in this preparation is, in part, attributable to an action of PATE, although the enzyme has not been purified to homogeneous state.In culture filtrates obtained from two saprophytic isolates of Ps. fluorescens, only a trace of trans-eliminase activity was detected. From these results, it is proposed that pathogenic pseudomonads are able to secrete pectolytic enzyme(s), causing degradation of plant tissues, but saprophytes have a little or no ability to produce them in this culture medium.
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Claims 3
Claim · model-written summary
N-6122 filtrate decreased sliced radish dry weight about 12% after eight hours at 30C.
- Taxon
- radish
Raphanus sativuse2 - Treatment
- Dialyzed culture filtrate of N-6122e0
- Interactor
- N-6122e0pathogen
- Outcome
- per cent loss in dry weight of radishe2
- Direction
- decreasee1
- Value
- about 12%e1
- Qualifier
- after incubation at 30C for 8 hourse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Dialyzed culture filtrate of N-6122, mainly containing PATE, showed typical action to degradate plant tissues”
e1“decrease about 12% of sliced tissues, after incubation at 30C for 8 hours”
e2“per cent loss in dry weight of radish”
Claim · model-written summary
The authors attribute part of plant tissue degradation by the N-6122 filtrate to PATE.
- Taxon
- radishRaphanus sativuse1
- Interactor
- N-6122e2pathogen
- Gene
- PATEe0
- Outcome
- tissue degradatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the tissue degradation in this preparation is, in part, attributable to an action of PATE”
e1“dry weight of radish”
e2“Dialyzed culture filtrate of N-6122, mainly containing PATE”
Claim · model-written summary
N-6122 filtrate had tissue-macerating properties similar to PATE, with shared pH and heat responses.
- Taxon
- radishRaphanus sativuse1
- Interactor
- N-6122e2pathogen
- Gene
- PATEe0
- Outcome
- physical properties of tissuemacerating agente0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The physical properties of tissuemacerating agent in dialyzed filtrate were similar to those of PATE. They responded in the same way to pH and temperature, viz, inactivation by lower or higher pH value and heating”
e1“dry weight of radish”
e2“Dialyzed culture filtrate of N-6122”
The same questions in other papers
pathogen product · growth · Raphanus sativus (radish)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- positive
- 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.