Abstract
Exposure of the roots of Alnus glutinosa (L.) Gaertn. to white light stimulated within 5 days a substantial increase in the content of quercetin and kaempferol, two major flavonols in acid hydrolysates of both roots and root exudates. Both compounds were detected also in hydrolysates of root extracts of Myrica gale and Casuarina equisetifolia, the latter a species not nodulated by Frankia strains effective on Alnus. A 7-fold reduction in nodulation of seedlings 12 days after inoculation with Frankia preincubated for 24 h with kaempferol supported the possibility that flavonols might be involved in the regulation of nodulation. Nodulation of seedling roots that were inoculated with Frankia and then exposed to light was inhibited by 50% after 11 days compared with seedlings with darkened roots. This effect of light treatment was preceded by a 30-fold increase in quercetin and kaempferol. The inhibitory effects on nodulation of preincubation of Frankia with kaempferol persisted for 18 days after inoculation, but there was no significant effect on nodulation after prolonging exposure of the root system to light for 40 days. The data support indirectly the suggestion that the balance between stimulatory and inhibitory flavonoids in roots and root exudates may contribute to the regulation of nodulation of actinorhizal plants.Key words: Alnus glutinosa, flavonoids, Frankia, kaempferol, nodulation, roots.
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Claims 9
Claim · model-written summary
Exposing Alnus glutinosa roots to white light increased the content of quercetin and kaempferol within 5 days.
- Taxon
- Alnus glutinosa
.jpg?width=60)
Alnus glutinosae0 - Organ / stage
- rootse0
- Treatment
- white lighte0
- Outcome
- content of quercetin and kaempferole0
- Direction
- increasee0
- Qualifier
- within 5 dayse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Exposure of the roots of Alnus glutinosa (L.) Gaertn. to white light stimulated within 5 days a substantial increase in the content of quercetin and kaempferol”
Claim · model-written summary
Quercetin and kaempferol were also detected in hydrolysates of root extracts of Myrica gale.
- Taxon
- Myrica gale
.jpg?width=60)
Myrica galee0 - Organ / stage
- root extractse0
- Outcome
- Both compounds were detectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Both compounds were detected also in hydrolysates of root extracts of Myrica gale and Casuarina equisetifolia”
Claim · model-written summary
Quercetin and kaempferol were also detected in hydrolysates of root extracts of Casuarina equisetifolia, a species not nodulated by Frankia strains effective on Alnus.
- Taxon
- Casuarina equisetifolia
Casuarina equisetifoliae0 - Organ / stage
- root extractse0
- Outcome
- Both compounds were detectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both compounds were detected also in hydrolysates of root extracts of Myrica gale and Casuarina equisetifolia”
Claim · model-written summary
Preincubating Frankia for 24 h with kaempferol caused a 7-fold reduction in nodulation of Alnus glutinosa seedlings 12 days after inoculation.
- Taxon
- Alnus glutinosaAlnus glutinosat0
- Treatment
- Frankia preincubated for 24 h with kaempferole0
- Outcome
- nodulatione0
- Direction
- reductione0
- Value
- 7-folde0
FrankiaNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Alnus glutinosa”
e0“A 7-fold reduction in nodulation of seedlings 12 days after inoculation with Frankia preincubated for 24 h with kaempferol”
Claim · model-written summary
Nodulation of Frankia-inoculated seedlings exposed to light was inhibited by 50% after 11 days compared with seedlings with darkened roots.
- Taxon
- Alnus glutinosaAlnus glutinosat0
- Treatment
- exposed to lighte0
- Outcome
- Nodulatione0
- Direction
- inhibitede0
- Value
- 50%e0
- Comparator
- seedlings with darkened rootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Alnus glutinosa”
e0“Nodulation of seedling roots that were inoculated with Frankia and then exposed to light was inhibited by 50% after 11 days compared with seedlings with darkened roots”
Claim · model-written summary
The light-induced inhibition of nodulation was preceded by a 30-fold increase in quercetin and kaempferol.
- Taxon
- Alnus glutinosaAlnus glutinosat0
- Treatment
- light treatmente0
- Outcome
- quercetin and kaempferole0
- Direction
- increasee0
- Value
- 30-folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Alnus glutinosa”
e0“This effect of light treatment was preceded by a 30-fold increase in quercetin and kaempferol”
Claim · model-written summary
The inhibitory effect on nodulation of preincubating Frankia with kaempferol persisted for 18 days after inoculation.
- Taxon
- Alnus glutinosaAlnus glutinosat0
- Treatment
- preincubation of Frankia with kaempferole0
- Outcome
- nodulatione0
- Direction
- inhibitorye0
- Qualifier
- persisted for 18 days after inoculatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Alnus glutinosa”
e0“The inhibitory effects on nodulation of preincubation of Frankia with kaempferol persisted for 18 days after inoculation”
Claim · model-written summary
Prolonging exposure of the root system to light for 40 days had no significant effect on nodulation.
- Taxon
- Alnus glutinosaAlnus glutinosat0
- Treatment
- prolonging exposure of the root system to light for 40 dayse0
- Outcome
- nodulatione0
- Direction
- no significant effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Alnus glutinosa”
e0“there was no significant effect on nodulation after prolonging exposure of the root system to light for 40 days”
Claim · model-written summary
The authors suggest that the balance between stimulatory and inhibitory flavonoids in roots and root exudates may contribute to regulation of nodulation of actinorhizal plants.
Verbatim
e0“the balance between stimulatory and inhibitory flavonoids in roots and root exudates may contribute to the regulation of nodulation of actinorhizal plants”
The same questions in other papers
light · symbiosis · Alnus glutinosaPositive and negative results
1 in the opposite direction
- 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.