Abstract
With the objective to clarify the physiological significance of polyamines (PAs) in the photosynthetic apparatus, the present study investigated the effects of salt stress with and without foliar application of putrescine (Put) on the structure and function of the photosynthetic apparatus in cucumber. Salt stress at 75 mM NaCl for 7 days resulted in a severe reduction of photosynthesis. The fast chlorophyll afluorescence transient analysis showed that salt stress inhibited the maximum quantum yield of PSII photochemistry (F(v)/F(m)), mainly due to damage at the receptor side of PSII. In addition, salt stress decreased the density of active reaction centers and the structure performance. The microscopic analysis revealed that salt stress-induced destruction of the chloroplast envelope and increased the number of plastoglobuli along with aberrations in thylakoid membranes. Besides, salt stress caused a decrease in the content of endogenous PAs, conjugated and bound forms of spermidine and spermine in particular, in thylakoid membranes. However, applications of 8 mM Put alleviated the salt stress-mediated decrease in net photosynthetic rates (Pn) and actual efficiency of PSII(Φ(PSII)). Put increased PAs in thylakoid membranes and overcame the damaging effects of salt stress on the structure and function of the photosynthetic apparatus in salt-stressed plant leaves. Put application to control plants neither increased PAs in thylakoid membranes nor affected photosynthesis. These results indicate that PAs in chloroplasts play crucial roles in protecting the thylakoid membranes against the deleterious influences of salt stress. In addition, the present results point to the probability that the salt-induced dysfunction of photosynthesis is largely attributable to the loss of PAs in the photosynthetic apparatus.
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Claims 12
Claim · model-written summary
Salt stress at 75 mM NaCl for 7 days severely reduced photosynthesis in cucumber.
- Taxon
- Cucumis sativus
Cucumis sativust0 - Treatment
- Salt stress at 75 mM NaCl for 7 dayse1
- Outcome
- photosynthesise1
- Direction
- severe reductione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e1“Salt stress at 75 mM NaCl for 7 days resulted in a severe reduction of photosynthesis”
Claim · model-written summary
Salt stress inhibited the maximum quantum yield of PSII photochemistry in cucumber, mainly through damage at the PSII receptor side.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- salt stresse2
- Outcome
- maximum quantum yield of PSII photochemistry (F(v)/F(m))e2
- Direction
- inhibitede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e2“The fast chlorophyll afluorescence transient analysis showed that salt stress inhibited the maximum quantum yield of PSII photochemistry (F(v)/F(m)), mainly due to damage at the receptor side of PSII”
Claim · model-written summary
Salt stress decreased the density of active reaction centers in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- salt stresse3
- Outcome
- density of active reaction centerse3
- Direction
- decreasede3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e3“In addition, salt stress decreased the density of active reaction centers and the structure performance”
Claim · model-written summary
Salt stress caused destruction of the chloroplast envelope in cucumber leaves.
- Taxon
- Cucumis sativusCucumis sativust0
- Organ / stage
- chloroplast envelopee4
- Treatment
- salt stresse4
- Outcome
- destruction of the chloroplast envelopee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e4“The microscopic analysis revealed that salt stress-induced destruction of the chloroplast envelope and increased the number of plastoglobuli along with aberrations in thylakoid membranes”
Claim · model-written summary
Salt stress increased the number of plastoglobuli in cucumber chloroplasts.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- salt stresse4
- Outcome
- number of plastoglobulie4
- Direction
- increasede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e4“The microscopic analysis revealed that salt stress-induced destruction of the chloroplast envelope and increased the number of plastoglobuli along with aberrations in thylakoid membranes”
Claim · model-written summary
Salt stress caused aberrations in cucumber thylakoid membranes.
- Taxon
- Cucumis sativusCucumis sativust0
- Organ / stage
- thylakoid membranese4
- Treatment
- salt stresse4
- Outcome
- aberrations in thylakoid membranese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e4“The microscopic analysis revealed that salt stress-induced destruction of the chloroplast envelope and increased the number of plastoglobuli along with aberrations in thylakoid membranes”
Claim · model-written summary
Salt stress decreased the content of endogenous conjugated and bound spermidine and spermine in thylakoid membranes.
- Taxon
- Cucumis sativusCucumis sativust0
- Organ / stage
- thylakoid membranese5
- Treatment
- salt stresse5
- Outcome
- content of endogenous PAse5
- Direction
- decreasee5
- Qualifier
- conjugated and bound forms of spermidine and spermine in particulare5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e5“Besides, salt stress caused a decrease in the content of endogenous PAs, conjugated and bound forms of spermidine and spermine in particular, in thylakoid membranes”
Claim · model-written summary
Application of 8 mM putrescine alleviated the salt-stress decrease in net photosynthetic rate and actual PSII efficiency in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- 8 mM Pute6
- Outcome
- net photosynthetic rates (Pn) and actual efficiency of PSII(Φ(PSII))e6
- Direction
- alleviatede6
- Comparator
- salt stresse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e6“However, applications of 8 mM Put alleviated the salt stress-mediated decrease in net photosynthetic rates (Pn) and actual efficiency of PSII(Φ(PSII))”
Claim · model-written summary
Putrescine increased PAs in cucumber thylakoid membranes under salt stress.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- Pute7
- Outcome
- PAs in thylakoid membranese7
- Direction
- increasede7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e7“Put increased PAs in thylakoid membranes and overcame the damaging effects of salt stress on the structure and function of the photosynthetic apparatus in salt-stressed plant leaves”
Claim · model-written summary
Putrescine application to unstressed control plants did not increase PAs in thylakoid membranes or affect photosynthesis.
- Taxon
- Cucumis sativusCucumis sativust0
- Treatment
- Put application to control plantse1
- Outcome
- PAs in thylakoid membranese1
- Qualifier
- nor affected photosynthesise1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e1“Put application to control plants neither increased PAs in thylakoid membranes nor affected photosynthesis”
Claim · model-written summary
PAs in chloroplasts play crucial roles in protecting thylakoid membranes against salt stress in cucumber.
- Taxon
- Cucumis sativusCucumis sativust0
- Compound
- PAse1
- Outcome
- protecting the thylakoid membranese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e1“These results indicate that PAs in chloroplasts play crucial roles in protecting the thylakoid membranes against the deleterious influences of salt stress”
Claim · model-written summary
Salt-induced photosynthetic dysfunction is probably largely attributable to loss of PAs in the photosynthetic apparatus.
- Taxon
- Cucumis sativusCucumis sativust0
- Compound
- PAse1
- Outcome
- dysfunction of photosynthesise1
- Qualifier
- probabilitye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Effects of salt stress on the structure and function of the photosynthetic apparatus in Cucumis sativus and its protection by exogenous putrescine”
e1“In addition, the present results point to the probability that the salt-induced dysfunction of photosynthesis is largely attributable to the loss of PAs in the photosynthetic apparatus”
The same questions in other papers
putrescine · physiology: photosynthesis · Cucumis sativus (cucumber)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
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