Abstract
SUMMARY Botrytis fabae and B. cinerea , pathogens which cause ‘chocolate spot’ of beans ( Vicia faba L.) produced polygalacturonase abundantly in media containing pectic substances or soluble cellulose derivatives; only filtrates from cultures grown on poly‐pectate had pectinesterase activity and even this was relatively low. B. cinerea filtrates from media containing cellulose had appreciable cellulase (C x ) activity, but did not degrade insoluble wood cellulose; B. fabae filtrates were inactive in both respects. Cultures of both fungi on certain types of media readily macerated sections of bean stems and caused them to become brownish black in colour. Filtrates from cultures of both fungi had considerably lower polygalacturonase activities when leaf extracts were present in otherwise suitable media. The latent phenolase present in water extracts of leaves was activated by poly‐pectate, polygalacturonic acid, pectin and carboxymethylcellulose. Activation was most rapid near pH 4.5 and was negligible at pH 5.5 which was the optimum value for sodium dioctyl sulphosuccinate, one of the best activators so far described. Solutions of the polymers could be diluted with no great effect on activations. Lesions are produced more readily on old than on young leaves, and extracts of old leaves discolour more rapidly than do extracts of young leaves when exposed to activated phenolase from bean leaves. This is because young leaves contain some system which retards the development of the coloured products which are normally produced following the oxidation of phenols. Water extracts of bean leaves inactivate the polygalacturonase of both fungi. The polygalacturonase of B. fabae differed from that of B. cinerea in being rapidly inactivated after filtrates had been diluted with water, and by being inactivated quickly by cyanide. B. fabae polygalacturonase was inactivated relatively quickly by products formed after oxidation of dihydroxyphenylalanine, but was less affected when catechol was used; B. cinerea behaved in the opposite way. The mechanisms by which both fungi cause lesions on bean leaves are discussed in the light of the results summarized above.
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Claims 15
Claim · model-written summary
Both Botrytis fungi produced abundant polygalacturonase on suitable media.
- Taxon
- beanse0
- Interactor
- Botrytis fabae and B. cinerea
Botrytis cinerea
Botrytis fabaee0pathogen - Outcome
- produced polygalacturonase abundantlye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Botrytis fabae and B. cinerea , pathogens which cause ‘chocolate spot’ of beans ( Vicia faba L.) produced polygalacturonase abundantly in media containing pectic substances or soluble cellulose derivatives”
Claim · model-written summary
Only poly-pectate culture filtrates had relatively low pectinesterase activity.
Not reportedDirection
Verbatim
e0“only filtrates from cultures grown on poly‐pectate had pectinesterase activity and even this was relatively low”
t0“beans”
Claim · model-written summary
B. cinerea filtrates had cellulase activity but did not degrade insoluble wood cellulose.
- Taxon
- beanst0
- Interactor
- B. cinereaBotrytis cinereae0pathogent0
- Outcome
- appreciable cellulase (C x ) activitye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“B. cinerea filtrates from media containing cellulose had appreciable cellulase (C x ) activity, but did not degrade insoluble wood cellulose”
t0“beans (Vicia faba L.)—interactions between phenolase of host and pectic enzymes of the pathogen”
Claim · model-written summary
B. fabae filtrates were inactive for cellulase activity and wood cellulose degradation.
- Taxon
- beanst0
- Interactor
- B. fabaeBotrytis fabaee0pathogent0
- Outcome
- inactive in both respectse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“B. fabae filtrates were inactive in both respects”
t0“beans (Vicia faba L.)—interactions between phenolase of host and pectic enzymes of the pathogen”
Claim · model-written summary
Cultures of both fungi macerated bean stems and browned them.
- Taxon
- beane0
- Outcome
- macerated sections of bean stems and caused them to become brownish black in coloure0
Not reportedDirection
Verbatim
e0“Cultures of both fungi on certain types of media readily macerated sections of bean stems and caused them to become brownish black in colour”
Claim · model-written summary
Leaf extracts lowered polygalacturonase activity of both fungi.
Verbatim
e0“Filtrates from cultures of both fungi had considerably lower polygalacturonase activities when leaf extracts were present in otherwise suitable media”
t0“beans”
Claim · model-written summary
Four pectic or cellulose substances activated latent leaf phenolase.
- Taxon
- beant0
- Treatment
- poly‐pectate, polygalacturonic acid, pectin and carboxymethylcellulosee0
- Outcome
- latent phenolasee0
- Direction
- activatede0
Not reportedComparator
Verbatim
e0“The latent phenolase present in water extracts of leaves was activated by poly‐pectate, polygalacturonic acid, pectin and carboxymethylcellulose”
t0“beans”
Claim · model-written summary
Activation was fastest near pH 4.5 and negligible at pH 5.5.
Verbatim
e0“Activation was most rapid near pH 4.5 and was negligible at pH 5.5”
t0“beans”
Claim · model-written summary
Older leaves developed lesions more readily than younger leaves.
Verbatim
e0“Lesions are produced more readily on old than on young leaves”
t0“beans”
Claim · model-written summary
Old leaf extracts discolored faster than young leaf extracts after exposure to activated phenolase.
Verbatim
e0“extracts of old leaves discolour more rapidly than do extracts of young leaves when exposed to activated phenolase from bean leaves”
Claim · model-written summary
Young leaves were interpreted as containing a system that delays colored oxidation products.
Verbatim
e0“young leaves contain some system which retards the development of the coloured products which are normally produced following the oxidation of phenols”
t0“beans”
Claim · model-written summary
Bean leaf extracts inactivated polygalacturonase of both fungi.
- Taxon
- beane0
- Treatment
- Water extracts of bean leavese0
- Outcome
- polygalacturonase of both fungie0
- Direction
- inactivatee0
Not reportedComparator
Verbatim
e0“Water extracts of bean leaves inactivate the polygalacturonase of both fungi”
Claim · model-written summary
B. fabae polygalacturonase was rapidly inactivated after dilution or by cyanide.
Verbatim
e0“The polygalacturonase of B. fabae differed from that of B. cinerea in being rapidly inactivated after filtrates had been diluted with water, and by being inactivated quickly by cyanide”
t0“beans”
Claim · model-written summary
Oxidized dihydroxyphenylalanine products inactivated B. fabae enzyme faster than catechol products.
Verbatim
e0“B. fabae polygalacturonase was inactivated relatively quickly by products formed after oxidation of dihydroxyphenylalanine, but was less affected when catechol was used”
t0“beans”
Claim · model-written summary
B. cinerea enzyme showed the opposite response to the two oxidation products.
Not reportedDirection
Verbatim
e0“B. cinerea behaved in the opposite way”
t0“beans”
The same questions in other papers
botanical · physiology: enzyme activity · Phaseolus vulgaris (common bean)Results agree
2 papers in the same direction as this paper
- positive
- positive
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.