scholarly journals Effect of Two-week High-temperature Treatment on Flower Quality and Abscission of Rosa L. ‘Belinda’s Dream’ and ‘RADrazz’ (KnockOut®) under Controlled Growing Environments

HortScience ◽  
2014 ◽  
Vol 49 (6) ◽  
pp. 701-705 ◽  
Author(s):  
Ockert Greyvenstein ◽  
Brent Pemberton ◽  
Terri Starman ◽  
Genhua Niu ◽  
David Byrne
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Dry Weight ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Stress Conditions ◽  
High Temperature Treatment ◽  
Continuous Control ◽  
Knock Out ◽  
Stage Of Development

The decline in sales of garden roses can, in part, be attributed to the lack of well-adapted cultivars. Successful selection for any trait requires an accurate phenotyping protocol. Apart from field screening, a protocol for phenotyping high-temperature tolerance in garden roses is yet to be established. An experiment was conducted to determine the stage of development when flowers were most sensitive to high-temperature stress. Liners of Rosa L. ‘Belinda’s Dream (BD) and the Knock Out® rose ‘RADrazz’ (KO) were planted in a soilless medium and grown in a greenhouse. Established plants were pruned retaining several nodes with leaves on two main shoots and treatments started. The experiment was conducted in growth chambers held at either 24/17 °C (control) or 36/28 °C (stress) day/night temperatures. Six time and duration temperature treatments included 8 weeks of continuous control conditions, 8 weeks of continuous stress conditions, and four sequential 2-week high-temperature shock treatments. Continuously stressed plants flowered in the least amount of days but did not differ from the continuous control-treated plants based on nonlinear thermal unit accumulation until flowering. Both cultivars had a 70% reduction in flower dry weight under continuous stress conditions. Flowers were most sensitive to high-temperature stress at the visible bud stage, which corresponds to Weeks 5 to 6 and Weeks 7 to 8 for BD and Weeks 3 to 4 and Weeks 5 to 6 for KO, respectively. KO was more resistant to flower abscission than BD when treated at the visible bud stage, but no difference in flower dry weight reduction between BD and KO was found. The number of vegetative nodes to the flower was unaffected by treatment and differed between the cultivars.

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 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 150 Color Fading of Rose Petals Due to a Transient High Temperature Stress

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 415D-415
Author(s):  
M. Oren-Shamir ◽  
Dela Gal
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Flower Color ◽  
High Temperature Stress ◽  
Anthocyanin Synthesis ◽  
Flower Buds ◽  
Total Anthocyanin ◽  
Stage Of Development ◽  
Red Color ◽  
Color Fading

Changes in temperature during rose flower development, often cause a significant fading of flower color, decreasing its market value. We are studying the effect of transient high temperature stress on red roses (Rosa ×hybrida, `Jaguar'). We have found that a transient temperature stress of 39/18 °C day/night respectively for 3 days, in comparison to the growth temperature of 26/18 °C, caused a significant fading to flower color at a mature bud stage. The plant organ responsible for color fading is the flower bud only. When the stress was applied to the whole plant, not including the flower buds, there was no change on the mature bud color. We have also shown that there are specific flower developmental stages sensitive to the transient increase in temperature. Flower buds at the critical stage of development, that have been exposed to temperature increase have a faded pink-red color when matured. Total anthocyanin levels of faded flowers, due to temperature stress, decreased to ≈50%. In addition, the ratio between the two anthocyanidins composing the red color, cyanidin and pelargonidin, changed dramatically due to the temperature stress: flowers on plants that have not overcome a temperature stress had a ration of 1:1, while those that have faded due to the temperature stress have a ration of 2:1 of pelargonidin to cyanidin, respectively. These findings hint to specific stages of anthocyanin synthesis, that are hypersensitive to increased temperature. We are now in the process of identifying and characterizing these stages.

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.

scholarly journals Molecular mechanism underlying Pyropia haitanensis PhHsp22-mediated increase in the high-temperature tolerance of Chlamydomonas reinhardtii

2021 ◽  
Author(s):  
Jing Chang ◽  
Jianzhi Shi ◽  
Jianzhang Lin ◽  
Dehua Ji ◽  
Yan Xu ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Chlamydomonas Reinhardtii ◽  
Temperature Stress ◽  
Small Heat Shock Protein ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Pyropia Haitanensis ◽  
High Temperature Tolerance

AbstractGlobal warming is one of the key limiting factors affecting the cultivation of Pyropia haitanensis which is an economically important macroalgae species grown in southern China. However, the mechanism underlying the high-temperature tolerance of P. haitanensis remains largely unknown. In a previous study, we showed that the expression of the small heat shock protein 22 gene (Hsp22) is upregulated in P. haitanensis in response to high-temperature stress, but the associated regulatory mechanism was not fully elucidated. In this study, a transgenic Chlamydomonas reinhardtii expression system was used to functionally characterize P. haitanensis Hsp22. Our analyses indicated that the C-terminal of PhHsp22 is highly conserved and contains an A-crystal structure domain. A phylogenetic analysis revealed PhHsp22 is not closely related to small heat shock protein genes in other species. Additionally, PhHsp22 expression significantly increased at 3 and 6 h after initiating 33 °C treatment, which improved the survival rate of transgenic C. reinhardtii during the early stage of high-temperature treatment. The further transcriptome analysis revealed that PhHsp22 expression can promote pathways related to energy metabolism, metabolites metabolism, and protein homeostasis in transgenic C. reinhardtii cells exposed to high temperatures. Therefore, PhHsp22 may be crucial for the response of Pyropia species to high-temperature stress. Furthermore, this gene may be useful for breeding new high-temperature algal strains.

scholarly journals Involvement of Ca2+ in Regulation of Physiological Indices and Heat Shock Factor Expression in Four Iris germanica Cultivars under High-temperature Stress

2014 ◽  
Vol 139 (6) ◽  
pp. 687-698 ◽  
Author(s):  
Jing Mao ◽  
Hongliang Xu ◽  
Caixia Guo ◽  
Jun Tong ◽  
Yanfang Dong ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Temperature Stress ◽  
High Temperatures ◽  
Soluble Protein ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Heat Shock Factor ◽  
High Temperature Tolerance ◽  
Iris Germanica

Although tolerance to high temperature is crucial to the summer survival of Iris germanica cultivars in subtropical areas, few physiological studies have been conducted on this topic previously. To remedy this, this study explored the physiological response and expression of heat shock factor in four I. germanica cultivars with varying levels of thermotolerance. The plants’ respective degrees of high-temperature tolerance were evaluated by measuring the ratio and area of withered leaves under stress. Several physiological responses to high temperatures were investigated, including effects on chlorophyll, antioxidant enzymes, proline, and soluble protein content in the leaves of four cultivars. CaCl2 was sprayed on ‘Gold Boy’ and ‘Royal Crusades’ considered being sensitive to high temperatures to study if Ca2+ could improve the tolerance, and LaCl3 was sprayed on ‘Music Box’ and ‘Galamadrid’ with better high-temperature tolerance to test if calcium ion blocker could decrease their tolerance. Heat shock factor genes were partially cloned according to the conserved region sequence, and expression changes to high-temperature stress with CaCl2 or LaCl3 treatments were thoroughly analyzed. Results showed that high temperature is the primary reason for large areas of leaf withering. The ratio and area of withered leaves on ‘Music Box’ and ‘Galamadrid’ were smaller than ‘Gold Boy’ and ‘Royal Crusades’. CaCl2 slowed the degradation of chlorophyll content and increased proline and soluble protein in ‘Gold Boy’ and ‘Royal Crusades’ but had no significant effect on activating peroxidase or superoxide to improve high-temperature tolerance. Genetic expression of heat shock factor in ‘Gold Boy’ and ‘Royal Crusades’ was upregulated by Ca2+ at later stages of leaf damage under high-temperature stress. LaCl3 down-regulated the physiological parameters and expression level of heat shock factor in ‘Music Box’ and ‘Galamadrid’. These results suggest that different I. germanica cultivars have varying high-temperature tolerance and furthermore that Ca2+ regulates their physiological indicators and expression level of heat shock factor under stress.

scholarly journals Evaluation of stress indices for screening of rice cultivars for high temperature tolerance

2019 ◽  
Vol 56 (4) ◽  
pp. 341-351
Author(s):  
Veronica N ◽  
Ashoka Rani Y ◽  
Subrahmanyam D ◽  
Narasimha Rao KL ◽  
Lal Ahamad M ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Geometric Mean ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Growing Period ◽  
High Temperature Tolerance ◽  
Severe Reduction ◽  
Stress Susceptibility

High temperature during the crop growing period is detrimental as it results in reduction of yield. A diverse set of rice germplasm consisting of 60 genotypes was grown at two different sowing times (normal and late) and were exposed naturally to high temperature in the late sown condition (stress). There was a severe reduction in grain yield and spikelet fertility in all the genotypes in the late sown crop. Yield based indices were computed based on grain yield recorded under normal and stress conditions. Indices Stress Susceptibility Index (STI), Geometric Mean Production (GMP), Mean Production (MP), Yield Index (YI), Modified stress tolerance (K1STI and K2STI) were positively correlated with yield recorded under both normal and high temperature stress condition and can be considered as suitable indices for screening of rice genotypes under high temperature conditions. Ranking genotypes based on the indices revealed that Rasi, HKR47, IR64, Khudaridhan, Akshayadhan and N22 exhibited the highest mean rank and hence they can be identified as heat-tolerant genotypes. ADT43, Vandana, IR36, MTU1001, ADT49 and Krishnahamsa had a lower rank and were identified as susceptible genotypes to high-temperature stress.

scholarly journals Dampak Suhu Tinggi terhadap Pertumbuhan dan Hasil Tanaman Padi

2020 ◽  
Vol 47 (3) ◽  
pp. 248-254
Author(s):  
Usamah Jaisyurahman ◽  
Desta Wirnas ◽  
Trikoesoemaningtyas ◽  
Dan Heni Purnamawati
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Growth And Development ◽  
Rice Variety ◽  
Grain Filling ◽  
High Temperature Stress ◽  
High Temperature Treatment ◽  
Tolerance Index ◽  
Grain Number ◽  
Grain Number Per Panicle

Global warming becomes a pressure in food production sustainability because it affected crop growth and development. The purpose of this study was to obtain information on the effect of high-temperature stress on the growth and development phase of rice and to evaluate the genotype for tolerance to high-temperature stress. Two environment conditions were used in the field and greenhouse of IPB Cikabayan experimental field, IPB University from August 2016 until February 2017. The study used varieties of IPB 4S, IPB 6R, Mekongga, and Situ Patenggang. High-temperature treatment was done by transferring the rice plants to the greenhouse at 50 days after transplanting. Observations were made on the generative phase in two different environmental conditions. The results showed that the total tillers number, filled grain number per panicle, unfilled grain number per panicle, total grain number per panicle, grain filling rate, percentage of filled grain and filled grain weight per plant had different responses among rice genotypes due to high-temperature stress. High-temperature decreased pollen fertility in all genotypes, which classified IPB 4S as a sensitive genotype and Mekongga as a tolerant genotype. This information could be useful for development and improving rice variety to anticipate high-temperature stress. Keywords: Climate change, fertility, pollen, stress tolerance index

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