Abstract
Exposure of pea (Pisum sativum L. cv Sparkle) roots to light suppressed nodulation and induced an increase in ethylene production by roots. Dim light did not affect the number of infections per centimeter of root on the primary root, but most infections were blocked when the infection thread was in the epidermis or in the outer cortex. This is the same stage of infection on lateral roots that is blocked by exogenous ethylene. Silver, an inhibitor of ethylene action, increased nodule number on roots exposed to dim light. Exposure of pea roots to nitrate also suppressed nodulation and induced increased ethylene production by roots. However, induction of ethylene production from roots by nitrate was less than that induced by dim light. Nitrate decreased the number of infections per centimeter of lateral root. With 25 mm nitrate, about half of the infections that occurred were blocked in the epidermis or in the outer cortex. Silver did not reverse the inhibitory effects of nitrate on nodulation. Our data indicate that the inhibitory effect of light may occur via increased ethylene production, but they do not support the hypothesis that ethylene mediates nitrate control of nodule number. The possible role of ethylene in regulating nodule number should be studied in experiments in which light is excluded from the roots.
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Claims 13
Claim · model-written summary
Light suppressed nodulation of pea roots.
- Taxon
- Pisum sativum
Lathyrus oleraceust0 - Material
- cv Sparklee1
- Organ / stage
- rootse1
- Treatment
- lighte1
- Outcome
- nodulatione1
- Direction
- suppressede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e1“Exposure of pea (Pisum sativum L. cv Sparkle) roots to light suppressed nodulation and induced an increase in ethylene production by roots”
Claim · model-written summary
Light increased ethylene production by pea roots.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- rootse1
- Treatment
- lighte1
- Outcome
- ethylene production by rootse1
- Direction
- increasee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e1“Exposure of pea (Pisum sativum L. cv Sparkle) roots to light suppressed nodulation and induced an increase in ethylene production by roots”
Claim · model-written summary
Dim light did not affect the number of infections per centimeter of root on the primary root.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- primary roote2
- Treatment
- Dim lighte2
- Outcome
- number of infections per centimeter of roote2
- Direction
- no_changeinferrede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e2“Dim light did not affect the number of infections per centimeter of root on the primary root, but most infections were blocked when the infection thread was in the epidermis or in the outer cortex”
Claim · model-written summary
Most infections on pea roots exposed to dim light were blocked when the infection thread was in the epidermis or outer cortex.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- Dim lighte2
- Outcome
- infections were blockede2
- Qualifier
- when the infection thread was in the epidermis or in the outer cortexe2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e2“Dim light did not affect the number of infections per centimeter of root on the primary root, but most infections were blocked when the infection thread was in the epidermis or in the outer cortex”
Claim · model-written summary
Silver, an inhibitor of ethylene action, increased nodule number on pea roots exposed to dim light.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- rootse3
- Treatment
- Silver, an inhibitor of ethylene actione3
- Outcome
- nodule numbere3
- Direction
- increasede3
- Qualifier
- roots exposed to dim lighte3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e3“Silver, an inhibitor of ethylene action, increased nodule number on roots exposed to dim light”
Claim · model-written summary
Nitrate suppressed nodulation of pea roots.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- rootse4
- Treatment
- nitratee4
- Outcome
- nodulatione4
- Direction
- suppressede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e4“Exposure of pea roots to nitrate also suppressed nodulation and induced increased ethylene production by roots”
Claim · model-written summary
Nitrate increased ethylene production by pea roots.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- rootse4
- Treatment
- nitratee4
- Outcome
- ethylene production by rootse4
- Direction
- increasede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e4“Exposure of pea roots to nitrate also suppressed nodulation and induced increased ethylene production by roots”
Claim · model-written summary
Induction of ethylene production from roots by nitrate was less than that induced by dim light.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- nitratee5
- Outcome
- induction of ethylene production from roots by nitratee5
- Direction
- lesse5
- Comparator
- dim lighte5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e5“However, induction of ethylene production from roots by nitrate was less than that induced by dim light”
Claim · model-written summary
Nitrate decreased the number of infections per centimeter of lateral root.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Organ / stage
- lateral roote6
- Treatment
- Nitratee6
- Outcome
- number of infections per centimeter of lateral roote6
- Direction
- decreasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e6“Nitrate decreased the number of infections per centimeter of lateral root”
Claim · model-written summary
With 25 mm nitrate, about half of the infections were blocked in the epidermis or outer cortex.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- 25 mm nitratee7
- Outcome
- blocked in the epidermis or in the outer cortexe7
- Value
- about halfe7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e7“With 25 mm nitrate, about half of the infections that occurred were blocked in the epidermis or in the outer cortex”
Claim · model-written summary
Silver did not reverse the inhibitory effects of nitrate on nodulation.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Treatment
- Silvere7
- Outcome
- nodulatione7
- Direction
- no_changeinferrede7
- Comparator
- nitratee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e7“Silver did not reverse the inhibitory effects of nitrate on nodulation”
Claim · model-written summary
Light may inhibit nodulation via increased ethylene production.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- inhibitory effect of lighte7
- Qualifier
- increased ethylene productione7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e7“Our data indicate that the inhibitory effect of light may occur via increased ethylene production”
Claim · model-written summary
The data do not support that ethylene mediates nitrate control of nodule number.
- Taxon
- Pisum sativumLathyrus oleraceust0
- Outcome
- nitrate control of nodule numbere7
- Qualifier
- ethylene mediates nitrate controle7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Pisum sativum L. cv Sparkle”
e7“they do not support the hypothesis that ethylene mediates nitrate control of nodule number”
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