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.

Changes in photosynthesis, chlorophyll fluorescence, and antioxidant enzymes of mulberry (Morus ssp.) in response to salinity and high-temperature stress

Biologia ◽  
2013 ◽  
Vol 68 (3) ◽  
Author(s):  
Cui Yu ◽  
Shujun Huang ◽  
Xingming Hu ◽  
Wen Deng ◽  
Chao Xiong ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
High Temperature ◽  
Quantum Yield ◽  
Photosystem Ii ◽  
Peroxidase Activity ◽  
High Temperature Stress ◽  
The Other ◽  
Fluorescence Parameters ◽  
Photosystem Ii Photochemistry ◽  
Chl Fluorescence

AbstractPhotosynthesis, chlorophyll (Chl) fluorescence, and antioxidant enzymes were measured in the mulberry (Morus spp.) cultivars Da 10, Hongguo 2, Anza 1, and Taiwan 72C002, which were subjected to salinity and high-temperature stress (STS; 0.1%, 0.3%, and 0.5% NaCl concentrations, 34.5°C–40.5°C/27.8°C–29.2°C day/night temperatures). Control plants were watered with 1 L of full-strength Hoagland’s nutrient solution with no added NaCl. Net photosynthetic rate (P N), stomatal conductance (g s), and effective quantum yield of photosystem II photochemistry (ΦPSII) increased in Anza 1 and Taiwan 72C002 under 0.1% STS but decreased in Da 10 and Hongguo 2 compared with the control. However, all the above parameters, including Chl content, maximum quantum yield of photosystem II photochemistry (Fv/Fm), nonphotochemical quenching (NPQ), and maximum carboxylation velocity of Rubisco (V cmax, decreased in Taiwan 72C002, Honggua 2, and Da 10 under 0.3% and 0.5% STS, suggesting that photoinhibition occurred under severe STS. Under STS, there were no significant changes in P N, Fv/Fm, ΦPSII, ascorbate peroxidase (APX) activity, superoxide dismutase (SOD) activity, catalase activity, superoxide anion radical (O2−) content, malondialdehyde (MDA) content, soluble sugar content (SSC), and leaf biomass in Anza 1 even at 0.5% STS, showing that Anza 1 displays high resistance to STS. In addition, peroxidase activity was significantly higher in Anza 1 than in the other mulberry cultivars. Significant adverse effects of severe salinity on photosynthesis and Chl fluorescence parameters were observed in Da 10. Additionally, SOD, peroxidase, and APX activities were lower in Da 10, whereas O2− and MDA contents were higher in comparison with the other mulberry cultivars under 0.3% and 0.5% STS, suggesting that Da 10 had low resistance to STS. These results show that 0.1% STS had a positive effect on photosynthesis and Chl fluorescence parameters in Anza 1 and Taiwan 72C002, and higher peroxidase activity can to a certain extent explain the higher STS tolerance in Anza 1. Damages to DSM photosystems might be related to lower SOD, POD, and APX activities, which resulted in the accumulation of reactive oxygen species.

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.

Sign in / Sign up

Export Citation Format

Share Document