scholarly journals Chloroplast ultrastructure regeneration with protection of photosystem II is responsible for the functional ‘stay-green’ trait in wheat

2012 ◽  
Vol 36 (3) ◽  
pp. 683-696 ◽  
Author(s):  
P. G. LUO ◽  
K. J. DENG ◽  
X. Y. HU ◽  
L. Q. LI ◽  
X. LI ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Chloroplast Ultrastructure ◽  
Stay Green

scholarly journals Excess Zinc Supply Reduces Cadmium Uptake and Mitigates Cadmium Toxicity Effects on Chloroplast Structure, Oxidative Stress, and Photosystem II Photochemical Efficiency in Salvia sclarea Plants

Toxics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 36
Author(s):  
Ilektra Sperdouli ◽  
Ioannis-Dimosthenis S. Adamakis ◽  
Anelia Dobrikova ◽  
Emilia Apostolova ◽  
Anetta Hanć ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Photosystem Ii ◽  
Adverse Effects ◽  
Cadmium Toxicity ◽  
Photochemical Efficiency ◽  
Antimicrobial Properties ◽  
Chloroplast Ultrastructure ◽  
Salvia Sclarea ◽  
Psii Photochemistry ◽  
Hoagland Nutrient Solution

Salvia sclarea L. is a Cd2+ tolerant medicinal herb with antifungal and antimicrobial properties cultivated for its pharmacological properties. However, accumulation of high Cd2+ content in its tissues increases the adverse health effects of Cd2+ in humans. Therefore, there is a serious demand to lower human Cd2+ intake. The purpose of our study was to evaluate the mitigative role of excess Zn2+ supply to Cd2+ uptake/translocation and toxicity in clary sage. Salvia plants were treated with excess Cd2+ (100 μM CdSO4) alone, and in combination with Zn2+ (900 μM ZnSO4), in modified Hoagland nutrient solution. The results demonstrate that S. sclarea plants exposed to Cd2+ toxicity accumulated a significant amount of Cd2+ in their tissues, with higher concentrations in roots than in leaves. Cadmium exposure enhanced total Zn2+ uptake but also decreased its translocation to leaves. The accumulated Cd2+ led to a substantial decrease in photosystem II (PSII) photochemistry and disrupted the chloroplast ultrastructure, which coincided with an increased lipid peroxidation. Zinc application decreased Cd2+ uptake and translocation to leaves, while it mitigated oxidative stress, restoring chloroplast ultrastructure. Excess Zn2+ ameliorated the adverse effects of Cd2+ on PSII photochemistry, increasing the fraction of energy used for photochemistry (ΦPSII) and restoring PSII redox state and maximum PSII efficiency (Fv/Fm), while decreasing excess excitation energy at PSII (EXC). We conclude that excess Zn2+ application eliminated the adverse effects of Cd2+ toxicity, reducing Cd2+ uptake and translocation and restoring chloroplast ultrastructure and PSII photochemical efficiency. Thus, excess Zn2+ application can be used as an important method for low Cd2+-accumulating crops, limiting Cd2+ entry into the food chain.

scholarly journals Photoinhibition and loss of photosystem II reaction centre proteins during senescence of soybean leaves. Enhancement of photoinhibition by the ‘stay-green’ mutation cytG

2002 ◽  
Vol 115 (3) ◽  
pp. 468-478 ◽  
Author(s):  
Juan J. Guiamét ◽  
Esa Tyystjärvi ◽  
Taina Tyystjärvi ◽  
Isaac John ◽  
Marja Kairavuo ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Reaction Centre ◽  
Stay Green ◽  
Soybean Leaves

Linking sensitivity of photosystem II to UV-B with chloroplast ultrastructure and UV-B absorbing pigments contents in A. thaliana L. phyAphyB double mutants

2020 ◽  
Vol 91 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Vladimir D. Kreslavski ◽  
Xin Huang ◽  
Galina Semenova ◽  
Alexandra Khudyakova ◽  
Galina Shirshikova ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Chloroplast Ultrastructure

High temperature reduces photosynthesis in maize leaves by damaging chloroplast ultrastructure and photosystem II

2020 ◽  
Vol 206 (5) ◽  
pp. 548-564 ◽  
Author(s):  
Yu‐Ting Li ◽  
Wei‐Wei Xu ◽  
Bai‐Zhao Ren ◽  
Bin Zhao ◽  
Jiwang Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Photosystem Ii ◽  
Chloroplast Ultrastructure ◽  
Maize Leaves

scholarly journals Physiological and Transcriptomic Analysis Reveals the Responses and Difference to High Temperature and Humidity Stress in Two Melon Genotypes

2022 ◽  
Vol 23 (2) ◽  
pp. 734
Author(s):  
Jinyang Weng ◽  
Asad Rehman ◽  
Pengli Li ◽  
Liying Chang ◽  
Yidong Zhang ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
High Temperature ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Chloroplast Ultrastructure ◽  
Future Research ◽  
Leaf Water Content ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Temperature And Humidity

Due to the frequent occurrence of continuous high temperatures and heavy rain in summer, extremely high-temperature and high-humidity environments occur, which seriously harms crop growth. High temperature and humidity (HTH) stress have become the main environmental factors of combined stress in summer. The responses of morphological indexes, physiological and biochemical indexes, gas exchange parameters, and chlorophyll fluorescence parameters were measured and combined with chloroplast ultrastructure and transcriptome sequencing to analyze the reasons for the difference in tolerance to HTH stress in HTH-sensitive ‘JIN TAI LANG’ and HTH-tolerant ‘JIN DI’ varieties. The results showed that with the extension of stress time, the superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) activities of the two melon varieties increased rapidly, the leaf water content increased, and the tolerant varieties showed stronger antioxidant capacity. Among the sensitive cultivars, Pn, Fv/Fm, photosystem II, and photosystem I chlorophyll fluorescence parameters were severely inhibited and decreased rapidly with the extension of stress time, while the HTH-tolerant cultivars slightly decreased. The cell membrane and chloroplast damage in sensitive cultivars were more severe, and Lhca1, Lhca3, and Lhca4 proteins in photosystem II and Lhcb1-Lhcb6 proteins in photosystem I were inhibited compared with those in the tolerant cultivar. These conclusions may be the main reason for the different tolerances of the two cultivars. These findings will provide new insights into the response of other crops to HTH stress and also provide a basis for future research on the mechanism of HTH resistance in melon.

Change of Chloroplast Ultrastructure in Radish Seedlings under the Influence of the Photosystem II-Herbicide Bentazon

1980 ◽  
Vol 35 (7-8) ◽  
pp. 656-664 ◽  
Author(s):  
D. Meier ◽  
H. K. Lichtenthaler ◽  
G. Burkard
Keyword(s):  
Photosystem Ii ◽  
Raphanus Sativus ◽  
Photosynthetic Apparatus ◽  
Chloroplast Ultrastructure ◽  
Raphanus Sativus L ◽  
Radish Seedlings

The influence of the photosystem II-herbicide bentazon on the ultrastructure of chloroplasts of radish seedlings (Raphanus sativus L.) was investigated with special emphasis on thylakoid development and grana formation. Bentazon application (10-3 ᴍ) induces the formation of broader and higher grana stacks (grana width: 0.5-0.6 μm; greatest frequency: 3-8 thylakoids per granum) than in the control plants (grana width: 0.3 μm; greatest frequency: 2-4 thylakoids per granum). Furthermore, the amount of chloroplast lamellae is enhanced, as are the stacking degree of thylakoids and the grana area. The chloroplasts of bentazon-treated plants appear to be shorter and thicker than in the controls and show all signs of a shade-type adaptation of the photosynthetic apparatus.

scholarly journals Direct energy transfer from photosystem II to photosystem I is the major regulator of winter sustainability of Scots pine

2020 ◽  
Author(s):  
Pushan Bag ◽  
Volha Chukhutsina ◽  
Zishan Zhang ◽  
Suman Paul ◽  
Alexander G. Ivanov ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Photosystem Ii ◽  
Scots Pine ◽  
Photosystem I ◽  
Photosynthetic Apparatus ◽  
Chloroplast Ultrastructure ◽  
Fluorescence Analysis ◽  
Seasonal Adaptation ◽  
Direct Energy ◽  
Direct Energy Transfer

AbstractEvergreen conifers in boreal forests can survive extremely cold (freezing) temperatures during the long dark winter and fully recover during the summer. A phenomenon called ‘sustained quenching’ putatively provides photoprotection and enables their survival, but its precise molecular and physiological mechanisms are not understood. To unveil them, we have analyzed the seasonal adaptation of the photosynthetic machinery of Scots pine (Pinus sylvestris) trees by monitoring multi-year changes in weather, chlorophyll fluorescence, chloroplast ultrastructure, and changes in pigment-protein composition. Recorded Photosystem II and Photosystem I performance parameters indicate that highly dynamic structural and functional seasonal rearrangements of the photosynthetic apparatus occur. Although several mechanisms might contribute to ‘sustained quenching’ of winter/early spring pine needles, time-resolved fluorescence analysis shows that extreme down-regulation of photosystem II activity along with direct energy transfer from photosystem II to photosystem I plays a major role. This mechanism is enabled by extensive thylakoid destacking allowing for mixing of PSII with PSI complexes. These two linked phenomena play crucial roles in winter acclimation and protection.Graphical abstract

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