scholarly journals Exogenous spermidine enhances the photosynthetic and antioxidant capacity of rice under heat stress during early grain-filling period

2018 ◽  
Vol 45 (9) ◽  
pp. 911 ◽  
Author(s):  
She Tang ◽  
Haixiang Zhang ◽  
Ling Li ◽  
Xia Liu ◽  
Lin Chen ◽  
...  
Keyword(s):  
High Temperature ◽  
Antioxidant Capacity ◽  
Temperature Stress ◽  
Soluble Sugars ◽  
High Temperature Stress ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Fluorescence Maximum

High temperature has adverse effects on rice growth by inhibiting the flag leaf photosynthetic and antioxidant capacity, which can be alleviated by various exogenous chemicals such as spermidine (Spd). However, the role of Spd in conferring heat tolerance in rice is not well documented. Conventional japonica rice varieties Wuyunjing 24 and Ningjing 3 were treated with high temperatures at 37.5/27.0°C (day/night) and foliar sprayed with 1 mmol L−1 Spd after flowering. Results showed activities of superoxide dismutase (SOD) and peroxidase (POD) activities were deceased during high temperature treatment and eventually lead to the malondialdehyde (MDA) accumulation. Exogenous Spd significantly increased both SOD and POD activities at the later stage of high-temperature treatment, and reduced MDA accumulation were identified in both rice varieties. Application of Spd further increased the amount of soluble sugars during high temperature stress and that maintained the osmotic equilibrium of rice leaves. Spd significantly increased photosystem II (ΦPSII), photosynthetic electron transport rate (ETR), variable fluorescence/maximum fluorescence ratio (Fvʹ/Fmʹ), stomatal conductance and the photochemical reaction of light energy ratio (Pr), and ultimately improved the photosynthetic and transpiration rate during high temperature stress. In conclusion, exogenous Spd can effectively alleviate the adverse consequences of high temperature and could be further applied to provide strategies in mitigating the challenges of global warming-induced yield loss and other possible relevant issues.

scholarly journals BmCncC/keap1-pathway is involved in high-temperature induced metamorphosis regulation of silkworm, Bombyx mori

2018 ◽  
Author(s):  
Jinxin Li ◽  
Tingting Mao ◽  
Zhengting Lu ◽  
Mengxue Li ◽  
Zhengting Lu ◽  
...  
Keyword(s):  
High Temperature ◽  
Bombyx Mori ◽  
Temperature Stress ◽  
Hormone Level ◽  
High Temperature Stress ◽  
Temperature Treatment ◽  
Endogenous Hormone ◽  
High Temperature Treatment ◽  
Regulation Mechanism ◽  
The Relationship

AbstractThe global warming has affected the growth, development and reproduction of insects. However, the molecular mechanism of high temperature stress-mediated metamorphosis regulation of lepidopteran insect has not been elucidated. In this study, the relationship between the insect developmental process and endogenous hormone level was investigated under high temperature (36 ° C) stress in Bombyx mori (B. mori). The results showed that the duration of 5th instar larvae were shortened by 28 ± 2 h, and the content of 20E was up-regulated significantly after 72 h of high temperature treatment, while the transcription levels of 20E response genes E93, Br-C, USP, E75 were up-regulated 1.35, 1.25, 1.28, and 1.27-fold, respectively. The high temperature treatment promoted the phosphorylation level of Akt and the downstream BmCncC/keap1 pathway was activated, the transcription levels of 20E synthesis-related genes cyp302a1, cyp306a1, cyp314a1 and cyp315a1 were up-regulated by 1.12, 1.51, 2.17 and 1.23-fold, respectively. After treatment with double stranded RNA of BmCncC (dsBmCncC) in BmN cells, the transcription levels of cyp302a1 and cyp306a1 were significantly decreased, whereas up-regulated by 2.15 and 1.31-fold, respectively, after treatment with CncC activator Curcumin. These results suggested that BmCncC/keap1-mediated P450 genes (cyp302a1, cyp306a1) expression resulted in the changes of endogenous hormone level, which played an important role in the regulation of metamorphosis under high temperature stress. Studies provide novel clues for understanding the CncC/keap1 pathway-mediated metamorphosis regulation mechanism in insects.Author SummaryMammalian nuclear transcription factor Nrf2 (NF-E2-related factor 2) plays an important role in the stress response of cells. CncC is a homolog of mammalian Nrf2 in insect, regulating the genes expression of insect antioxidant enzymes and cytochrome P450 detoxification enzyme. Evidence suggests that the CncC/Keap1 pathway also plays an important role in regulating insect development. Here, we investigated the regulatory mechanism between the CncC/Keap1 pathway and metabolism of silkworm hormones in Lepidoptera. We found that high temperature induction accelerated the development of silkworm, the ecdysone content and related metabolic genes in hemolymph were significantly up-regulated, the CncC/Keap1 pathway was activated, and the expression of BmCncC was significantly increased, indicating that the Cncc/Keap1 pathway plays an important role in this process. The expression of cyp302a1 and cyp306a1 was significantly decreased by RNA interference with BmCncC, which indicated that CncC in silkworm had a regulatory relationship with downstream 20E synthetic gene. In summary, the results indicate that the CncC/Keap1 pathway plays an important role in regulating hormone metabolism in silkworm, providing a basis for further study of the relationship between CncC/Keap1 pathway and development in insects.

scholarly journals Alterations in the leaf lipidome of Brassica carinata under high-temperature stress

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zolian Zoong Lwe ◽  
Saroj Sah ◽  
Leelawatti Persaud ◽  
Jiaxu Li ◽  
Wei Gao ◽  
...  
Keyword(s):  
Fatty Acids ◽  
High Temperature ◽  
Temperature Stress ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
High Temperature Stress ◽  
Temperature Treatment ◽  
Brassica Carinata ◽  
High Temperature Treatment ◽  
Heat Tolerant

Abstract Background Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry. Results Temperature treatment significantly affected the growth and development of Avanza 641. Both high-temperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18:3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts. Conclusions The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties.

scholarly journals Phosphoproteomic analysis of lettuce (Lactuca sativa L.) reveals starch and sucrose metabolism functions during bolting induced by high temperature

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244198
Author(s):  
Xiaoxiao Qin ◽  
Panpan Li ◽  
Shaowei Lu ◽  
Yanchuan Sun ◽  
Lifeng Meng ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Lactuca Sativa ◽  
Molecular Mechanisms ◽  
Soluble Sugar ◽  
High Temperature Stress ◽  
Temperature Treatment ◽  
Sucrose Metabolism ◽  
High Temperature Treatment ◽  
Lactuca Sativa L

High temperatures induce early bolting in lettuce (Lactuca sativa L.), which decreases both quality and production. However, knowledge of the molecular mechanism underlying high temperature promotes premature bolting is lacking. In this study, we compared lettuce during the bolting period induced by high temperatures (33/25 °C, day/night) to which raised under controlled temperatures (20/13 °C, day/night) using iTRAQ-based phosphoproteomic analysis. A total of 3,814 phosphorylation sites located on 1,766 phosphopeptides from 987 phosphoproteins were identified after high-temperature treatment,among which 217 phosphoproteins significantly changed their expression abundance (116 upregulated and 101 downregulated). Most phosphoproteins for which the abundance was altered were associated with the metabolic process, with the main molecular functions were catalytic activity and transporter activity. Regarding the functional pathway, starch and sucrose metabolism was the mainly enriched signaling pathways. Hence, high temperature influenced phosphoprotein activity, especially that associated with starch and sucrose metabolism. We suspected that the lettuce shorten its growth cycle and reduce vegetative growth owing to changes in the contents of starch and soluble sugar after high temperature stress, which then led to early bolting/flowering. These findings improve our understanding of the regulatory molecular mechanisms involved in lettuce bolting.

scholarly journals Natural variations of SLG1 confer high-temperature tolerance in indica rice

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xu ◽  
Li Zhang ◽  
Shujun Ou ◽  
Ruci Wang ◽  
Yueming Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Indica Rice ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Coding Regions ◽  
High Temperature Tolerance ◽  
Living Organisms

Abstract With global warming and climate change, breeding crop plants tolerant to high-temperature stress is of immense significance. tRNA 2-thiolation is a highly conserved form of tRNA modification among living organisms. Here, we report the identification of SLG1 (Slender Guy 1), which encodes the cytosolic tRNA 2-thiolation protein 2 (RCTU2) in rice. SLG1 plays a key role in the response of rice plants to high-temperature stress at both seedling and reproductive stages. Dysfunction of SLG1 results in plants with thermosensitive phenotype, while overexpression of SLG1 enhances the tolerance of plants to high temperature. SLG1 is differentiated between the two Asian cultivated rice subspecies, indica and japonica, and the variations at both promoter and coding regions lead to an increased level of thiolated tRNA and enhanced thermotolerance of indica rice varieties. Our results demonstrate that the allelic differentiation of SLG1 confers indica rice to high-temperature tolerance, and tRNA thiolation pathway might be a potential target in the next generation rice breeding for the warming globe.

scholarly journals High-temperature stress during drying improves subsequent rice (Oryza sativa L.) seed longevity

2017 ◽  
Vol 27 (4) ◽  
pp. 281-291 ◽  
Author(s):  
Katherine J. Whitehouse ◽  
Fiona R. Hay ◽  
Richard H. Ellis
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Oryza Sativa L ◽  
Subsequent Development ◽  
High Temperature Stress ◽  
Seed Longevity ◽  
In Planta ◽  
Rice Varieties ◽  
Stage Of Development ◽  
Rice Seeds

AbstractPost-harvest drying prolongs seed survival in air-dry storage; previous research has shown a benefit of drying moist rice seeds at temperatures greater than recommended for genebanks (5–20°C). The aim of this study was to determine whether there is a temperature limit for safely drying rice seeds, and to explore whether the benefit to longevity is caused by high-temperature stress or continued seed development. Seeds of two rice varieties were harvested at different stages of development and dried initially either over silica gel, or intermittently (8 h day–1) or continuously (24 h day–1) over MgCl2 at temperatures between 15 and 60°C for up to 3 days. Seeds dried more rapidly the warmer the temperature. Subsequent seed longevity in hermetic storage (45°C and 10.9% moisture content) was substantially improved by increase in drying temperature up to 45°C in both cultivars, and also with further increase from 45 to 60°C in cv. ‘Macassane’. The benefit of high-temperature drying to subsequent longevity tended to diminish the later the stage of development at seed harvest. Intermittent or continuous drying at high temperatures provided broadly similar improvements to longevity, but with the greatest improvements detected in a few treatment combinations with continuous drying. Heated-air drying of rice seeds harvested before maturity improved their subsequent storage longevity by more than that which occurred during subsequent development in planta, which may have resulted from the triggering of protection mechanisms in response to high-temperature stress.

Sign in / Sign up

Export Citation Format

Share Document