Pub Date : 2023-02-20eCollection Date: 2023-01-01DOI: 10.32615/ps.2023.004
H Xu, X Chu, K J Gou, D X Jiang, Q Q Li, C G Lv, Z P Gao, G X Chen
Photooxidative damage causes early leaf senescence and plant cell death. In this study, a light-sensitive rice cultivar, 812HS, and a non-light-sensitive cultivar, 812S, were used to investigate early leaf photooxidation. Leaf tips of 812HS exhibited yellowing under a light intensity of 720 μmol(photon) m-2 s-1, accompanied by a decrease in chlorophyll and carotenoids, but 812S was unaffected. The photosynthetic performance of 812HS was also poorer than that of 812S. The H2O2, O2·-, and malondialdehyde content increased sharply in 812HS, and associated antioxidant enzymes were inhibited. The degradation of core proteins in both PSI and PSII, as well as other photosynthesis-related proteins, was accelerated in 812HS. When shaded [180 μmol(photon) m-2 s-1], 812HS recovered to normal. Therefore, our findings suggested excess light disturbed the balance of ROS metabolism, leading to the destruction of the antioxidant system and photosynthetic organs, and thus triggering the senescence of rice leaves.
{"title":"The photosynthetic function analysis for leaf photooxidation in rice.","authors":"H Xu, X Chu, K J Gou, D X Jiang, Q Q Li, C G Lv, Z P Gao, G X Chen","doi":"10.32615/ps.2023.004","DOIUrl":"10.32615/ps.2023.004","url":null,"abstract":"<p><p>Photooxidative damage causes early leaf senescence and plant cell death. In this study, a light-sensitive rice cultivar, 812HS, and a non-light-sensitive cultivar, 812S, were used to investigate early leaf photooxidation. Leaf tips of 812HS exhibited yellowing under a light intensity of 720 μmol(photon) m<sup>-2</sup> s<sup>-1</sup>, accompanied by a decrease in chlorophyll and carotenoids, but 812S was unaffected. The photosynthetic performance of 812HS was also poorer than that of 812S. The H<sub>2</sub>O<sub>2</sub>, O<sub>2</sub> <sup>·-</sup>, and malondialdehyde content increased sharply in 812HS, and associated antioxidant enzymes were inhibited. The degradation of core proteins in both PSI and PSII, as well as other photosynthesis-related proteins, was accelerated in 812HS. When shaded [180 μmol(photon) m<sup>-2</sup> s<sup>-1</sup>], 812HS recovered to normal. Therefore, our findings suggested excess light disturbed the balance of ROS metabolism, leading to the destruction of the antioxidant system and photosynthetic organs, and thus triggering the senescence of rice leaves.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"20 1","pages":"48-57"},"PeriodicalIF":2.1,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515825/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75649271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-16eCollection Date: 2023-01-01DOI: 10.32615/ps.2023.006
G Govindjee
I present here a personal perspective of the evolution of the two-light reaction two-pigment scheme for the electron transport in oxygenic photosynthesis - as I have lived through it - first as a graduate student of Robert Emerson, from September 1956-January 1959, and then of Eugene Rabinowitch from February 1959-September 1960. I have provided here some of the key published work in my way and have also provided a few photographs. It is essential to remind ourselves upfront that different individuals may have different recollections of the same event (see e.g., the Japanese movie 'Rashomon' https://en.wikipedia.org/wiki/Rashomon). Thus, I encourage others to write about their perspective. Further, I recognize, upfront, the support and encouragement I have received from Robert Blankenship for writing this perspective, and from Győző Garab for submission of this story to Photosynthetica. I begin my perspective with a dedication to Robert Emerson, whose pioneering work led to the concept of the two-light reaction two-pigment system in oxygenic photosynthesis.
{"title":"On the evolution of the concept of two light reactions and two photosystems for oxygenic photosynthesis: A personal perspective.","authors":"G Govindjee","doi":"10.32615/ps.2023.006","DOIUrl":"10.32615/ps.2023.006","url":null,"abstract":"<p><p>I present here a personal perspective of the evolution of the two-light reaction two-pigment scheme for the electron transport in oxygenic photosynthesis - as I have lived through it - first as a graduate student of Robert Emerson, from September 1956-January 1959, and then of Eugene Rabinowitch from February 1959-September 1960. I have provided here some of the key published work in my way and have also provided a few photographs. It is essential to remind ourselves upfront that different individuals may have different recollections of the same event (<i>see e.g.</i>, the Japanese movie 'Rashomon' https://en.wikipedia.org/wiki/Rashomon). Thus, I encourage others to write about their perspective. Further, I recognize, upfront, the support and encouragement I have received from Robert Blankenship for writing this perspective, and from Győző Garab for submission of this story to <i>Photosynthetica</i>. I begin my perspective with a dedication to Robert Emerson, whose pioneering work led to the concept of the two-light reaction two-pigment system in oxygenic photosynthesis.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"22 1","pages":"37-47"},"PeriodicalIF":2.1,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515826/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72714097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-10eCollection Date: 2023-01-01DOI: 10.32615/ps.2023.005
M Ekinci, M Turan, S Ors, A Dursun, E Yildirim
The current study examined the H2S applications on growth, biochemical and physiological parameters of bean seedlings under saline conditions. The findings of the study indicated that salt stress decreased plant growth and development, photosynthetic activity, and mineral and hormone content [excluding abscisic acid (ABA)] in bean seedlings. Plant and root fresh mass and dry mass with H2S applications increased as compared to the control treatment at the same salinity level. Both salinity and H2S treatments significantly affected the net assimilation rate, stomatal conductance, transpiration rate, and intercellular CO2 content of bean seedlings. Significant increases occurred in H2O2, malondialdehyde (MDA), proline, sucrose content, enzyme activity, and ABA content with salt stress. However, H2S applications inhibited the effects of salinity on plant growth, photosynthetic activity, and mineral content in beans. H2S applications reduced H2O2, MDA, proline, sucrose content, enzyme activity, and ABA content in beans. As a result, exogenous H2S applications could mitigate the negative impacts of salinity in beans.
{"title":"Improving salt tolerance of bean (<i>Phaseolus vulgaris</i> L.) with hydrogen sulfide.","authors":"M Ekinci, M Turan, S Ors, A Dursun, E Yildirim","doi":"10.32615/ps.2023.005","DOIUrl":"10.32615/ps.2023.005","url":null,"abstract":"<p><p>The current study examined the H<sub>2</sub>S applications on growth, biochemical and physiological parameters of bean seedlings under saline conditions. The findings of the study indicated that salt stress decreased plant growth and development, photosynthetic activity, and mineral and hormone content [excluding abscisic acid (ABA)] in bean seedlings. Plant and root fresh mass and dry mass with H<sub>2</sub>S applications increased as compared to the control treatment at the same salinity level. Both salinity and H<sub>2</sub>S treatments significantly affected the net assimilation rate, stomatal conductance, transpiration rate, and intercellular CO<sub>2</sub> content of bean seedlings. Significant increases occurred in H<sub>2</sub>O<sub>2</sub>, malondialdehyde (MDA), proline, sucrose content, enzyme activity, and ABA content with salt stress. However, H<sub>2</sub>S applications inhibited the effects of salinity on plant growth, photosynthetic activity, and mineral content in beans. H<sub>2</sub>S applications reduced H<sub>2</sub>O<sub>2</sub>, MDA, proline, sucrose content, enzyme activity, and ABA content in beans. As a result, exogenous H<sub>2</sub>S applications could mitigate the negative impacts of salinity in beans.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"37 1","pages":"25-36"},"PeriodicalIF":2.1,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515852/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88696725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-30eCollection Date: 2023-01-01DOI: 10.32615/ps.2023.003
S W Wang, C J Xing, C F Zhang, T Guo, H L Hao, Z Y Zhang, S Wang, J M Shu
To clarify the effect of leaf scorch on walnut leaf photosynthesis, photosynthetic parameters were measured in Juglans regia 'Wen185' and 'Xinxin2' symptom trees (WS, XS) and symptomless trees (WH, XH). At the early stage of infection and under the low-grade leaf scorch, WS showed significantly lower net photosynthetic rate (PN), stomatal limitation (Ls), and higher intercellular CO2 concentration (Ci) than those of WH. However, at the mid to late stage of infection and under the high-grade leaf scorch, WS showed significantly lower PN, Ci, the maximal quantum yield of PSII photochemistry and higher Ls, minimal fluorescence yield of the dark-adapted state, nonphotochemical quenching than those of WH, which would occur once Juglans regia 'Xinxin2' was infected. The above results indicated the effect of leaf scorch on walnut leaf photosynthesis was related to the walnut varieties and the duration and severity of the disease. Under the influence of leaf scorch, the decline in photosynthesis of Juglans regia 'Wen185' leaves changed from stomatal to nonstomatal restriction, while Juglans regia 'Xinxin2' leaves showed always nonstomatal restriction.
{"title":"Photosynthetic performance of walnut leaves during the occurrence of leaf scorch.","authors":"S W Wang, C J Xing, C F Zhang, T Guo, H L Hao, Z Y Zhang, S Wang, J M Shu","doi":"10.32615/ps.2023.003","DOIUrl":"10.32615/ps.2023.003","url":null,"abstract":"<p><p>To clarify the effect of leaf scorch on walnut leaf photosynthesis, photosynthetic parameters were measured in <i>Juglans regia</i> 'Wen185' and 'Xinxin2' symptom trees (WS, XS) and symptomless trees (WH, XH). At the early stage of infection and under the low-grade leaf scorch, WS showed significantly lower net photosynthetic rate (<i>P</i> <sub>N</sub>), stomatal limitation (L<sub>s</sub>), and higher intercellular CO<sub>2</sub> concentration (<i>C</i> <sub>i</sub>) than those of WH. However, at the mid to late stage of infection and under the high-grade leaf scorch, WS showed significantly lower <i>P</i> <sub>N</sub>, <i>C</i> <sub>i</sub>, the maximal quantum yield of PSII photochemistry and higher L<sub>s</sub>, minimal fluorescence yield of the dark-adapted state, nonphotochemical quenching than those of WH, which would occur once <i>Juglans regia</i> 'Xinxin2' was infected. The above results indicated the effect of leaf scorch on walnut leaf photosynthesis was related to the walnut varieties and the duration and severity of the disease. Under the influence of leaf scorch, the decline in photosynthesis of <i>Juglans regia</i> 'Wen185' leaves changed from stomatal to nonstomatal restriction, while <i>Juglans regia</i> 'Xinxin2' leaves showed always nonstomatal restriction.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"3 1","pages":"13-24"},"PeriodicalIF":2.1,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515811/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83791324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-25eCollection Date: 2023-01-01DOI: 10.32615/ps.2023.001
G Yokoyama, S Ono, D Yasutake, K Hidaka, T Hirota
The diurnal variations in the factors of photosynthesis reduction under well-watered greenhouse conditions remain poorly understood. We conducted diurnal measurements of gas exchange and chlorophyll fluorescence in strawberries (Fragaria × ananassa Duch.) for three sunny days. Quantitative limitation analysis was also conducted to investigate the diurnal variations of photosynthetic limitations [stomatal (SL), mesophyll (MCL), and biochemical limitation (BL)]. Under well-watered greenhouse conditions, a photosynthesis reduction was observed, and the respective limitations exhibited different diurnal changes based on the environmental stress severity. The main limitation was SL, varying between 11.3 and 27.1% around midday, whereas MCL and BL were in 4.3-14.2% and 1.7-8.5%, respectively, under relatively moderate conditions. However, both SL (11.2-34.2%) and MCL (4.8-26.4%) predominantly limited photosynthesis under relatively severe conditions, suggesting that stomatal closure was the main limitation and that the decline in mesophyll conductance was not negligible under strong environmental stress, even under well-watered greenhouse conditions.
{"title":"Diurnal changes in the stomatal, mesophyll, and biochemical limitations of photosynthesis in well-watered greenhouse-grown strawberries.","authors":"G Yokoyama, S Ono, D Yasutake, K Hidaka, T Hirota","doi":"10.32615/ps.2023.001","DOIUrl":"10.32615/ps.2023.001","url":null,"abstract":"<p><p>The diurnal variations in the factors of photosynthesis reduction under well-watered greenhouse conditions remain poorly understood. We conducted diurnal measurements of gas exchange and chlorophyll fluorescence in strawberries (<i>Fragaria × ananassa</i> Duch.) for three sunny days. Quantitative limitation analysis was also conducted to investigate the diurnal variations of photosynthetic limitations [stomatal (<i>S</i> <sub>L</sub>), mesophyll (<i>MC</i> <sub>L</sub>), and biochemical limitation (<i>B</i> <sub>L</sub>)]. Under well-watered greenhouse conditions, a photosynthesis reduction was observed, and the respective limitations exhibited different diurnal changes based on the environmental stress severity. The main limitation was <i>S</i> <sub>L</sub>, varying between 11.3 and 27.1% around midday, whereas <i>MC</i> <sub>L</sub> and <i>B</i> <sub>L</sub> were in 4.3-14.2% and 1.7-8.5%, respectively, under relatively moderate conditions. However, both <i>S</i> <sub>L</sub> (11.2-34.2%) and <i>MC</i> <sub>L</sub> (4.8-26.4%) predominantly limited photosynthesis under relatively severe conditions, suggesting that stomatal closure was the main limitation and that the decline in mesophyll conductance was not negligible under strong environmental stress, even under well-watered greenhouse conditions.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"1 1","pages":"1-12"},"PeriodicalIF":2.1,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515859/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91253990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-21eCollection Date: 2023-01-01DOI: 10.32615/ps.2022.048
S S Baroniya, K Jumrani, M Baroniya, K N Guruprasad, M Landi, S Kataria
In the current study, we used four soybean varieties PK-1029, PK-472, NRC-7, and Hardee to examine the effect of exclusion of solar UV radiation on photosynthetic efficiency and to test possible variety-dependent sensitivity to ambient UV (280-400 nm). Plants that were grown under UV exclusion filters had higher chlorophyll a and b, efficiencies of PSII and more active reaction centers indicated that PSII were substantially affected by solar UV radiation. The significant increase in net photosynthesis was linked to increased stomatal conductance and lower intercellular concentration of CO2 in UV-excluded plants. The exclusion of solar UV increased seed mass per plant in all soybean varieties as compared to the control; this indicates that ambient UV exclusions boost photosynthetic efficiency and improve soybean yield. The overall cumulative stress response index of four varieties implies that Hardee and PK-472 were more sensitive whereas NRC-7 and PK-1029 were resistant to ambient UV radiations.
{"title":"Intraspecific variation in photosynthetic efficiency in soybean (<i>Glycine max</i> L.) varieties towards solar ultraviolet radiations.","authors":"S S Baroniya, K Jumrani, M Baroniya, K N Guruprasad, M Landi, S Kataria","doi":"10.32615/ps.2022.048","DOIUrl":"10.32615/ps.2022.048","url":null,"abstract":"<p><p>In the current study, we used four soybean varieties PK-1029, PK-472, NRC-7, and Hardee to examine the effect of exclusion of solar UV radiation on photosynthetic efficiency and to test possible variety-dependent sensitivity to ambient UV (280-400 nm). Plants that were grown under UV exclusion filters had higher chlorophyll <i>a</i> and <i>b</i>, efficiencies of PSII and more active reaction centers indicated that PSII were substantially affected by solar UV radiation. The significant increase in net photosynthesis was linked to increased stomatal conductance and lower intercellular concentration of CO<sub>2</sub> in UV-excluded plants. The exclusion of solar UV increased seed mass per plant in all soybean varieties as compared to the control; this indicates that ambient UV exclusions boost photosynthetic efficiency and improve soybean yield. The overall cumulative stress response index of four varieties implies that Hardee and PK-472 were more sensitive whereas NRC-7 and PK-1029 were resistant to ambient UV radiations.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"50 1","pages":"203-214"},"PeriodicalIF":2.1,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515822/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77438951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20eCollection Date: 2022-01-01DOI: 10.32615/ps.2022.051
W Q Ke, Y R Pan, L H Chen, J D Huang, J J Zhang, X Y Long, M L Cai, C L Peng
In stressful environments, invasive plants acclimate more efficiently than native plants and hybridization mainly contributes to this process. We examined changes in the morphological characteristics, photosynthetic characteristics, and antioxidant capacity of Sphagneticola trilobata and its hybrids in a low-light environment to explore their invasiveness, with Sphagneticola calendulacea serving as the control. The morphological plasticity of S. trilobata was not dominant, the maximal photochemical efficiency of PSII, actual quantum yield of PSII, and electron transport rate of PSII increased and nonphotochemical quenching decreased, while S. calendulacea and the hybrid produced opposite results. S. trilobata showed fewer spots stained for reactive oxygen species in tissues, with an increase in superoxide dismutase activity. Although S. trilobata is a heliophilous plant, we found that the shade tolerance of S. trilobata and the hybrid were stronger than that of S. calendulacea, which may be one important mechanism of invasion.
{"title":"Adaptive photosynthetic strategies of the invasive plant <i>Sphagneticola trilobata</i> and its hybrid to a low-light environment.","authors":"W Q Ke, Y R Pan, L H Chen, J D Huang, J J Zhang, X Y Long, M L Cai, C L Peng","doi":"10.32615/ps.2022.051","DOIUrl":"10.32615/ps.2022.051","url":null,"abstract":"<p><p>In stressful environments, invasive plants acclimate more efficiently than native plants and hybridization mainly contributes to this process. We examined changes in the morphological characteristics, photosynthetic characteristics, and antioxidant capacity of <i>Sphagneticola trilobata</i> and its hybrids in a low-light environment to explore their invasiveness, with <i>Sphagneticola calendulacea</i> serving as the control. The morphological plasticity of <i>S. trilobata</i> was not dominant, the maximal photochemical efficiency of PSII, actual quantum yield of PSII, and electron transport rate of PSII increased and nonphotochemical quenching decreased, while <i>S. calendulacea</i> and the hybrid produced opposite results. <i>S. trilobata</i> showed fewer spots stained for reactive oxygen species in tissues, with an increase in superoxide dismutase activity. Although <i>S. trilobata</i> is a heliophilous plant, we found that the shade tolerance of <i>S. trilobata</i> and the hybrid were stronger than that of <i>S. calendulacea</i>, which may be one important mechanism of invasion.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"243 1","pages":"549-561"},"PeriodicalIF":2.1,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11558596/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91216525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aimed to determine the photosynthetic performance and differences in chlorophyll fluorescence (ChlF) parameters between Eulophia dentata and its companion species Bletilla formosana and Saccharum spontaneum when subjected to different photosynthetic photon flux density (PPFDs). Leaf surfaces were then illuminated with 50, 100 (low PPFDs), 300, 500, 800 (moderate PPFDs); 1,000; 1,500; and 2,000 (high PPFDs) μmol m-2·s-1, and the ChlF parameters were measured during the whole process. Increasing nonphotochemical quenching of ChlF and decreasing potential quantum efficiency of PSII, actual quantum efficiency of PSII, and quantum efficiency ratio of PSII in dark recovery from 0-60 min were observed in all leaves. A significant and negative relationship was detected between energy-dependent quenching (qE) and photoinhibition percent in three species under specific PPFD conditions, whereas a significant and positive relationship was detected between photoinhibitory quenching (qI) and photoinhibition percent. The qE and qI can be easily measured in the field and provide useful ecological indexes for E. dentata species restoration, habitat creation, and monitoring.
{"title":"Photosynthetic responses of <i>Eulophia dentata</i>, <i>Bletilla formosana</i>, and <i>Saccharum spontaneum</i> under various photosynthetic photon flux density conditions.","authors":"Y-H Lai, K-H Lin, C-P Liu, T-S Liao, M-Y Huang, C-W Wang, C-I Chen","doi":"10.32615/ps.2022.050","DOIUrl":"10.32615/ps.2022.050","url":null,"abstract":"<p><p>This study aimed to determine the photosynthetic performance and differences in chlorophyll fluorescence (ChlF) parameters between <i>Eulophia dentata</i> and its companion species <i>Bletilla formosana</i> and <i>Saccharum spontaneum</i> when subjected to different photosynthetic photon flux density (PPFDs). Leaf surfaces were then illuminated with 50, 100 (low PPFDs), 300, 500, 800 (moderate PPFDs); 1,000; 1,500; and 2,000 (high PPFDs) μmol m<sup>-2</sup>·s<sup>-1</sup>, and the ChlF parameters were measured during the whole process. Increasing nonphotochemical quenching of ChlF and decreasing potential quantum efficiency of PSII, actual quantum efficiency of PSII, and quantum efficiency ratio of PSII in dark recovery from 0-60 min were observed in all leaves. A significant and negative relationship was detected between energy-dependent quenching (q<sub>E</sub>) and photoinhibition percent in three species under specific PPFD conditions, whereas a significant and positive relationship was detected between photoinhibitory quenching (q<sub>I</sub>) and photoinhibition percent. The q<sub>E</sub> and q<sub>I</sub> can be easily measured in the field and provide useful ecological indexes for <i>E. dentata</i> species restoration, habitat creation, and monitoring.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"40 1","pages":"539-548"},"PeriodicalIF":2.1,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11558585/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85083842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01eCollection Date: 2023-01-01DOI: 10.32615/ps.2022.047
A Ivanov, A Kosobryukhov, V Kreslavski, S I Allakhverdiev
The changes in photosynthetic activity, as well as the activity of nitrogen-metabolism enzymes, the intensity of lipid peroxidation, and proline content were studied in Triticum aestivum L. plants after their incubation at a low CO2 concentration in a sealed chamber for 10 d. CO2 deficiency (-CO2) compared to normal CO2 concentration (control) led to a decrease in the rate of O2 gas exchange at the plateau of the light curve and quantum yield of photosynthesis. The maximum and effective quantum photochemical yields also decreased. CO2 deficiency reduced the activity of nitrate reductase, but increased the activities of nitrite reductase, glutamine synthetase, and glutamate dehydrogenase, and promoted proline accumulation. It is assumed that with a lack of CO2, an excess of nitrogen-containing compounds occurs, which must be removed from metabolic processes. Also, we suggest the partial storage of nitrogen in the form of nitrogen-containing compounds such as proline.
{"title":"Changes in the photosynthetic performance, the activity of enzymes of nitrogen metabolism, and proline content in the leaves of wheat plants after exposure to low CO<sub>2</sub> concentration.","authors":"A Ivanov, A Kosobryukhov, V Kreslavski, S I Allakhverdiev","doi":"10.32615/ps.2022.047","DOIUrl":"10.32615/ps.2022.047","url":null,"abstract":"<p><p>The changes in photosynthetic activity, as well as the activity of nitrogen-metabolism enzymes, the intensity of lipid peroxidation, and proline content were studied in <i>Triticum aestivum</i> L. plants after their incubation at a low CO<sub>2</sub> concentration in a sealed chamber for 10 d. CO<sub>2</sub> deficiency (-CO<sub>2</sub>) compared to normal CO<sub>2</sub> concentration (control) led to a decrease in the rate of O<sub>2</sub> gas exchange at the plateau of the light curve and quantum yield of photosynthesis. The maximum and effective quantum photochemical yields also decreased. CO<sub>2</sub> deficiency reduced the activity of nitrate reductase, but increased the activities of nitrite reductase, glutamine synthetase, and glutamate dehydrogenase, and promoted proline accumulation. It is assumed that with a lack of CO<sub>2</sub>, an excess of nitrogen-containing compounds occurs, which must be removed from metabolic processes. Also, we suggest the partial storage of nitrogen in the form of nitrogen-containing compounds such as proline.</p>","PeriodicalId":20157,"journal":{"name":"Photosynthetica","volume":"12 1","pages":"190-202"},"PeriodicalIF":2.1,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11515816/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88407908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}