Cytosolic HSC70s repress heat stress tolerance and enhance seed germination under salt stress conditions

Carrot production is constrained by high levels of heat stress during the germination stage in many global regions. Few studies have been published evaluating the effect of heat stress on carrot seed germination or screening for genetic heat stress tolerance. The objectives of this study were to evaluate the response of diverse carrot germplasm to heat stress, identify heat-tolerant germplasm that may be used by plant breeders, and define the appropriate temperature for assessing heat tolerance in germinating carrot seed. To identify an appropriate screening temperature, three commercial hybrids and an open pollinated variety were evaluated at five temperatures (24, 32.5, 35, 37.5, and 40 °C). In preliminary studies, 35 °C was identified as the optimal temperature for screening heat tolerance of carrot seed. Cultivated and wild carrot plant introductions (PIs) (n = 270) from the U.S. Department of Agriculture (USDA) National Plant Germplasm System (NPGS) representing 41 countries, inbred lines from the USDA Agricultural Research Service (n = 15), and widely grown commercial hybrids (n = 8) were evaluated for heat tolerance under heat stress and nonstress conditions (35 °C and 24 °C, respectively) by calculating absolute decrease in percent germination (AD), inhibition index (II), relative heat tolerance (RHT), and heat tolerance index (HTI). All measurements of heat tolerance identified significant differences among accessions; AD ranged from −13.0% to 86.7%, II ranged from 35.7% to 100.0%, RHT ranged from 0 to 1.36, and HTI ranged from 0.0 to 1.45. The broad-sense heritability (H2) calculations ranged from 0.64 to 0.86 for different traits, indicating a moderately strong genetic contribution to the phenotypic variation. Several wild carrot accessions and inbred lines displayed low levels of heat tolerance, whereas cultivated accessions PI 643114 (United States), PI 652400 and PI 652403 (Turkey), PI 652208 (China), and PI 652403 (Russia) were most heat tolerant. This is the first evaluation of heritability for heat stress tolerance during carrot seed germination, the first measure of HTI, and the first correlation calculation between heat and salt tolerance during germination in carrot.

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Ethylene involvement in the regulation of heat stress tolerance in plants

Plant Cell Reports ◽

10.1007/s00299-021-02675-8 ◽

2021 ◽

Author(s):

Peter Poór ◽

Kashif Nawaz ◽

Ravi Gupta ◽

Farha Ashfaque ◽

M. Iqbal R. Khan

Keyword(s):

Heat Stress ◽

Stress Tolerance ◽

Heat Stress Tolerance

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Evaluation of heat stress tolerance in spring wheat (Triticum aestivum L.) genotypes using stress tolerance indices in western region of Nepal

Journal of Agriculture and Food Research ◽

10.1016/j.jafr.2021.100179 ◽

2021 ◽

pp. 100179

Author(s):

Padam Bahadur Poudel ◽

Mukti Ram Poudel ◽

Ramesh Raj Puri

Keyword(s):

Triticum Aestivum ◽

Heat Stress ◽

Stress Tolerance ◽

Spring Wheat ◽

Triticum Aestivum L ◽

Western Region ◽

Heat Stress Tolerance ◽

Tolerance Indices

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Evaluation of Triticum durum–Aegilops tauschii derived primary synthetics as potential sources of heat stress tolerance for wheat improvement

Plant Genetic Resources ◽

10.1017/s1479262121000113 ◽

2021 ◽

Vol 19 (1) ◽

pp. 74-89

Author(s):

Amandeep Kaur ◽

Parveen Chhuneja ◽

Puja Srivastava ◽

Kuldeep Singh ◽

Satinder Kaur

Keyword(s):

Heat Stress ◽

Stress Tolerance ◽

Hexaploid Wheat ◽

Aegilops Tauschii ◽

Grain Filling ◽

World Population ◽

Potential Candidate ◽

Terminal Heat Stress ◽

Heat Stress Tolerance ◽

The Impact

AbstractAddressing the impact of heat stress during flowering and grain filling is critical to sustaining wheat productivity to meet a steadily increasing demand from a rapidly growing world population. Crop wild progenitor species of wheat possess a wealth of genetic diversity for several biotic and abiotic stresses, and morphological traits and can serve as valuable donors. The transfer of useful variation from the diploid progenitor, Aegilops tauschii, to hexaploid wheat can be done through the generation of synthetic hexaploid wheat (SHW). The present study targeted the identification of potential primary SHWs to introduce new genetic variability for heat stress tolerance. Selected SHWs were screened for different yield-associated traits along with three advanced breeding lines and durum parents as checks for assessing terminal heat stress tolerance under timely and late sown conditions for two consecutive seasons. Heat tolerance index based on the number of productive tillers and thousand grain weight indicated that three synthetics, syn9809 (64.32, 78.80), syn14128 (50.30, 78.28) and syn14135 (58.16, 76.03), were able to endure terminal heat stress better than other SHWs as well as checks. One of these synthetics, syn14128, recorded a minimum reduction in thousand kernel weight (21%), chlorophyll content (2.56%), grain width (1.07%) despite minimum grain-filling duration (36.15 d) and has been selected as a potential candidate for introducing the terminal heat stress tolerance in wheat breeding programmes. Breeding efforts using these candidate donors will help develop lines with a higher potential to express the desired heat stress-tolerant phenotype under field conditions.

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Genotype and Trait Specific Responses to Rapamycin Intake in Drosophila melanogaster

Insects ◽

10.3390/insects12050474 ◽

2021 ◽

Vol 12 (5) ◽

pp. 474

Author(s):

Palle Duun Rohde ◽

Asbjørn Bøcker ◽

Caroline Amalie Bastholm Jensen ◽

Anne Louise Bergstrøm ◽

Morten Ib Juul Madsen ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Heat Stress ◽

Side Effects ◽

Protein Kinase ◽

Stress Tolerance ◽

Treated Group ◽

Model System ◽

Treatment Efficiency ◽

Evolutionarily Conserved ◽

Heat Stress Tolerance

Rapamycin is a powerful inhibitor of the TOR (Target of Rapamycin) pathway, which is an evolutionarily conserved protein kinase, that plays a central role in plants and animals. Rapamycin is used globally as an immunosuppressant and as an anti-aging medicine. Despite widespread use, treatment efficiency varies considerably across patients, and little is known about potential side effects. Here we seek to investigate the effects of rapamycin by using Drosophila melanogaster as model system. Six isogenic D. melanogaster lines were assessed for their fecundity, male longevity and male heat stress tolerance with or without rapamycin treatment. The results showed increased longevity and heat stress tolerance for male flies treated with rapamycin. Conversely, the fecundity of rapamycin-exposed individuals was lower than for flies from the non-treated group, suggesting unwanted side effects of the drug in D. melanogaster. We found strong evidence for genotype-by-treatment interactions suggesting that a ‘one size fits all’ approach when it comes to treatment with rapamycin is not recommendable. The beneficial responses to rapamycin exposure for stress tolerance and longevity are in agreement with previous findings, however, the unexpected effects on reproduction are worrying and need further investigation and question common believes that rapamycin constitutes a harmless drug.

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HSP70-4 and farnesylated AtJ3 constitute a specific HSP70/HSP40-based chaperone machinery essential for prolonged heat stress tolerance in Arabidopsis

Journal of Plant Physiology ◽

10.1016/j.jplph.2021.153430 ◽

2021 ◽

pp. 153430

Author(s):

Tzu-Yun Wang ◽

Jia-Rong Wu ◽

Ngoc Kieu Thi Duong ◽

Chung-An Lu ◽

Ching-Hui Yeh ◽

...

Keyword(s):

Heat Stress ◽

Stress Tolerance ◽

Heat Stress Tolerance ◽

Prolonged Heat

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Overexpression of the Golden SNP-Carrying Orange Gene Enhances Carotenoid Accumulation and Heat Stress Tolerance in Sweetpotato Plants

Antioxidants ◽

10.3390/antiox10010051 ◽

2021 ◽

Vol 10 (1) ◽

pp. 51

Author(s):

So-Eun Kim ◽

Chan-Ju Lee ◽

Sul-U Park ◽

Ye-Hoon Lim ◽

Woo Sung Park ◽

...

Keyword(s):

Heat Stress ◽

Stress Tolerance ◽

Ipomoea Batatas ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Cauliflower Mosaic Virus ◽

Carotenoid Content ◽

35S Promoter ◽

Storage Roots ◽

Heat Stress Tolerance

Carotenoids function as photosynthetic accessory pigments, antioxidants, and vitamin A precursors. We recently showed that transgenic sweetpotato calli overexpressing the mutant sweetpotato (Ipomoea batatas [L.] Lam) Orange gene (IbOr-R96H), which carries a single nucleotide polymorphism responsible for Arg to His substitution at amino acid position 96, exhibited dramatically higher carotenoid content and abiotic stress tolerance than calli overexpressing the wild-type IbOr gene (IbOr-WT). In this study, we generated transgenic sweetpotato plants overexpressing IbOr-R96H under the control of the cauliflower mosaic virus (CaMV) 35S promoter via Agrobacterium-mediated transformation. The total carotenoid contents of IbOr-R96H storage roots (light-orange flesh) and IbOr-WT storage roots (light-yellow flesh) were 5.4–19.6 and 3.2-fold higher, respectively, than those of non-transgenic (NT) storage roots (white flesh). The β-carotene content of IbOr-R96H storage roots was up to 186.2-fold higher than that of NT storage roots. In addition, IbOr-R96H plants showed greater tolerance to heat stress (47 °C) than NT and IbOr-WT plants, possibly because of higher DPPH radical scavenging activity and ABA contents. These results indicate that IbOr-R96H is a promising strategy for developing new sweetpotato cultivars with improved carotenoid contents and heat stress tolerance.

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MES7 Modulates Seed Germination via Regulating Salicylic Acid Content in Arabidopsis

Plants ◽

10.3390/plants10050903 ◽

2021 ◽

Vol 10 (5) ◽

pp. 903

Author(s):

Wenrui Gao ◽

Yan Liu ◽

Juan Huang ◽

Yaqiu Chen ◽

Chen Chen ◽

...

Keyword(s):

Salicylic Acid ◽

Salt Stress ◽

Abiotic Stress ◽

Seed Germination ◽

Environmental Conditions ◽

Acid Content ◽

Hydrolytic Enzyme ◽

Stress Conditions ◽

Transitional Period ◽

Highly Sensitive

Seed germination is an important phase transitional period of angiosperm plants during which seeds are highly sensitive to different environmental conditions. Although seed germination is under the regulation of salicylic acid (SA) and other hormones, the molecular mechanism underlying these regulations remains mysterious. In this study, we determined the expression of SA methyl esterase (MES) family genes during seed germination. We found that MES7 expression decreases significantly in imbibed seeds, and the dysfunction of MES7 decreases SA content. Furthermore, MES7 reduces and promotes seed germination under normal and salt stress conditions, respectively. The application of SA restores the seed germination deficiencies of mes7 mutants under different conditions. Taking together, our observations uncover a MeSA hydrolytic enzyme, MES7, regulates seed germination via altering SA titer under normal and abiotic stress conditions.

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