scholarly journals Lipidome analysis of Symbiodiniaceae reveals possible mechanisms of heat stress tolerance in reef coral symbionts

Coral Reefs ◽  
2019 ◽  
Vol 38 (6) ◽  
pp. 1241-1253 ◽  
Author(s):  
S. Rosset ◽  
G. Koster ◽  
J. Brandsma ◽  
A. N. Hunt ◽  
A. D. Postle ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Lipid Composition ◽  
Elevated Temperatures ◽  
Reef Coral ◽  
Membrane Lipid ◽  
Steady Increase ◽  
Heat Stress Response ◽  
Photosynthetic Organisms

Abstract Climate change-induced global warming threatens the survival of key ecosystems including shallow water coral reefs. Elevated temperatures can disrupt the normal physiological functioning of photosynthetic organisms by altering the fluidity and permeability of chloroplast membranes that is defined and regulated by their lipid composition. Since the habitat-forming reef corals rely on the obligatory symbiosis with dinoflagellates of the family Symbiodiniaceae, their heat stress response can be expected to be strongly influenced by the symbiont's lipid metabolism. However, in contrast to the steady increase in the knowledge of the functioning of coral symbionts at the genomic and transcriptomic level, the understanding of their membrane lipid composition and regulation in response to temperature stress is lagging behind. We have utilised mass spectrometry-based lipidomic analyses to identify the key polar lipids that form the biological membranes of reef coral symbionts, comparing the thermotolerant species Durusdinium trenchii with the thermosensitive taxon Cladocopium C3, both hosted by Acropora valida. Our results indicate that the superior thermotolerance D. trenchii inside the host corals could be achieved through (1) the amount and saturation of sulfoquinovosyldiacylglycerols, in particular through putative photosystem II interactions, (2) the increased digalactosyldiacylglycerol to monogalactosyldiacylglycerol ratio with the potential to stabilise thylakoid membranes and integrated proteins, and (3) the chaperone-like function of lyso-lipids. Thereby, our study provides novel insights into the heat tolerance of coral symbionts, contributing to the understanding of the potential of coral reef ecosystems to respond and adjust to heat stress events that are becoming more frequent due to climate change. Finally, our identification of multiple mechanisms of heat tolerance in Symbiodiniaceae furthers the knowledge of the general stress physiology of photosynthetic organisms.

scholarly journals A single heat-stress bout induces rapid and prolonged heat acclimation in the California mussel, Mytilus californianus

2020 ◽  
Vol 287 (1940) ◽  
pp. 20202561
Author(s):  
Nicole E. Moyen ◽  
Rachel L. Crane ◽  
George N. Somero ◽  
Mark W. Denny
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Elevated Temperatures ◽  
Survival Rates ◽  
Extreme Temperature ◽  
Extreme Heat ◽  
Mytilus Californianus ◽  
Laboratory Findings ◽  
Heat Events

Climate change is not only causing steady increases in average global temperatures but also increasing the frequency with which extreme heating events occur. These extreme events may be pivotal in determining the ability of organisms to persist in their current habitats. Thus, it is important to understand how quickly an organism's heat tolerance can be gained and lost relative to the frequency with which extreme heating events occur in the field. We show that the California mussel, Mytilus californianus —a sessile intertidal species that experiences extreme temperature fluctuations and cannot behaviourally thermoregulate—can quickly (in 24–48 h) acquire improved heat tolerance after exposure to a single sublethal heat-stress bout (2 h at 30 or 35°C) and then maintain this improved tolerance for up to three weeks without further exposure to elevated temperatures. This adaptive response improved survival rates by approximately 75% under extreme heat-stress bouts (2 h at 40°C). To interpret these laboratory findings in an ecological context, we evaluated 4 years of mussel body temperatures recorded in the field. The majority (approx. 64%) of consecutive heat-stress bouts were separated by 24–48 h, but several consecutive heat bouts were separated by as much as 22 days. Thus, the ability of M. californianus to maintain improved heat tolerance for up to three weeks after a single sublethal heat-stress bout significantly improves their probability of survival, as approximately 33% of consecutive heat events are separated by 3–22 days. As a sessile animal, mussels likely evolved the capability to rapidly gain and slowly lose heat tolerance to survive the intermittent, and often unpredictable, heat events in the intertidal zone. This adaptive strategy will likely prove beneficial under the extreme heat events predicted with climate change.

Improving sustainable cotton production through enhanced resilience to climate change using mutation breeding.

2021 ◽  
pp. 145-156
Author(s):  
Manzoor Hussain ◽  
Ljupcho Jankuloski ◽  
M. Habib-ur-Rahman ◽  
Massoud Malek ◽  
Md. Kamrul Islam ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Mutation Breeding ◽  
Climatic Conditions ◽  
Cotton Production ◽  
Climate Conditions ◽  
Growing Seasons ◽  
Major Factors ◽  
High Yields

Abstract Cotton, being a leading commercial fibre crop, is grown on 20.5 million hectares in three major cotton-producing countries: China, India and Pakistan. Wide differences in yield per hectare exist among these countries and these are being aggravated by changing climate conditions, i.e. higher temperatures and significant seasonal and regional fluctuation in rainfall. Pakistan is one of the countries most affected by climate change. The disastrous effects of extreme periods of heat stress in cotton were very prominent in Pakistan during the growing seasons 2013-2014 (40-50% fruit abortion) and 2016-2017 (33% shortfall), which posed an alarming threat to the cotton-based economy of Pakistan. Poor resilience of the most commonly grown cotton varieties against extreme periods of heat stress are considered to be major factors for this drastic downfall in cotton production in Pakistan. Using the approach of induced mutation breeding, the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan, has demonstrated its capabilities in developing cotton mutants that can tolerate the changed climatic conditions and sustain high yields under contrasting environments. The results of studies on the phenological and physiological traits conferring heat tolerance are presented here for thermo-tolerant cotton mutants (NIAB-878, NIAB-545, NIAB-1048, NIAB-444, NIAB-1089, NIAB-1064, NIAB-1042) relative to FH-142 and FH-Lalazar. NIAB-878 excelled in heat tolerance by maintaining the highest anther dehiscence (82%) and minimum cell injury percentage (39%) along with maximum stomatal conductance (27.7 mmol CO2/m2/s), transpiration rate (6.89 μmol H2O/m2/s), net photosynthetic rate (44.6 mmol CO2/m2/s) and physiological water use efficiency (6.81 mmol CO2/μmol H2O) under the prevailing high temperatures.

scholarly journals The Algal Symbiont Modifies the Transcriptome of the Scleractinian Coral Euphyllia paradivisa During Heat Stress

2019 ◽  
Vol 7 (8) ◽  
pp. 256 ◽  
Author(s):  
Dalit ◽  
Keren ◽  
Eviatar ◽  
Hiba ◽  
Gal ◽  
...  
Keyword(s):  
Heat Stress ◽  
Differentially Expressed Genes ◽  
Elevated Temperatures ◽  
Negative Impact ◽  
Global Climate ◽  
Differentially Expressed ◽  
Heat Stress Response ◽  
Stress Genes ◽  
Mutualistic Symbiosis ◽  
Algal Symbiont

The profound mutualistic symbiosis between corals and their endosymbiotic counterparts, Symbiodiniaceae algae, has been threatened by the increase in seawater temperatures, leading to breakdown of the symbiotic relationship—coral bleaching. To characterize the heat-stress response of the holobiont, we generated vital apo-symbiotic Euphyllia paradivisa corals that lacked the endosymbiotic algae. Using RNA sequencing, we analyzed the gene expression of these apo-symbionts vs. symbiotic ones, to test the effect of the algal presence on the tolerance of the coral. We utilized literature-derived lists of “symbiosis differentially expressed genes” and “coral heat-stress genes” in order to compare between the treatments. The symbiotic and apo-symbiotic samples were segregated into two separate groups with several different enriched gene ontologies. Our findings suggest that the presence of endosymbionts has a greater negative impact on the host than the environmental temperature conditions experienced by the holobiont. The peak of the stress reaction was identified as 28 °C, with the highest number of differentially expressed genes. We suggest that the algal symbionts increase coral holobiont susceptibility to elevated temperatures. Currently, we can only speculate whether coral species, such as E. paradivisa, with the plasticity to also flourish as apo-symbionts, may have a greater chance to withstand the upcoming global climate change challenge.

scholarly journals Molecular Basis of the Defective Heat Stress Response in Mycobacterium leprae

2007 ◽  
Vol 189 (24) ◽  
pp. 8818-8827 ◽  
Author(s):  
Diana L. Williams ◽  
Tana L. Pittman ◽  
Mike Deshotel ◽  
Sandra Oby-Robinson ◽  
Issar Smith ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Elevated Temperatures ◽  
Transcriptional Response ◽  
Mycobacterium Leprae ◽  
Heat Stress Response ◽  
Regulatory Circuits ◽  
Shock Response

ABSTRACT Mycobacterium leprae, a major human pathogen, grows poorly at 37°C. The basis for its inability to survive at elevated temperatures was investigated. We determined that M. leprae lacks a protective heat shock response as a result of the lack of transcriptional induction of the alternative sigma factor genes sigE and sigB and the major heat shock operons, HSP70 and HSP60, even though heat shock promoters and regulatory circuits for these genes appear to be intact. M. leprae sigE was found to be capable of complementing the defective heat shock response of mycobacterial sigE knockout mutants only in the presence of a functional mycobacterial sigH, which orchestrates the mycobacterial heat shock response. Since the sigH of M. leprae is a pseudogene, these data support the conclusion that a key aspect of the defective heat shock response in M. leprae is the absence of a functional sigH. In addition, 68% of the genes induced during heat shock in M. tuberculosis were shown to be either absent from the M. leprae genome or were present as pseudogenes. Among these is the hsp/acr2 gene, whose product is essential for M. tuberculosis survival during heat shock. Taken together, these results suggest that the reduced ability of M. leprae to survive at elevated temperatures results from the lack of a functional transcriptional response to heat shock and the absence of a full repertoire of heat stress response genes, including sigH.

scholarly journals The genetic and molecular basis for improving heat stress tolerance in wheat

aBIOTECH ◽  
2021 ◽  
Author(s):  
Lv Sun ◽  
Jingjing Wen ◽  
Huiru Peng ◽  
Yingyin Yao ◽  
Zhaorong Hu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Tolerance ◽  
Heat Tolerance ◽  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Elevated Temperatures ◽  
New Technologies ◽  
Wheat Breeding ◽  
Heat Stress Tolerance ◽  
The Impact

AbstractWheat production requires at least ~ 2.4% increase per year rate by 2050 globally to meet food demands. However, heat stress results in serious yield loss of wheat worldwide. Correspondingly, wheat has evolved genetic basis and molecular mechanisms to protect themselves from heat-induced damage. Thus, it is very urgent to understand the underlying genetic basis and molecular mechanisms responsive to elevated temperatures to provide important strategies for heat-tolerant varieties breeding. In this review, we focused on the impact of heat stress on morphology variation at adult stage in wheat breeding programs. We also summarize the recent studies of genetic and molecular factors regulating heat tolerance, including identification of heat stress tolerance related QTLs/genes, and the regulation pathway in response to heat stress. In addition, we discuss the potential ways to improve heat tolerance by developing new technologies such as genome editing. This review of wheat responses to heat stress may shed light on the understanding heat-responsive mechanisms, although the regulatory network of heat tolerance is still ambiguous in wheat.

scholarly journals Sitosterol-mediated Antioxidant Regulation to Enhance Heat Tolerance in Creeping Bentgrass

2022 ◽  
Vol 147 (1) ◽  
pp. 18-24
Author(s):  
Stephanie Rossi ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
Leaf Senescence ◽  
Heat Tolerance ◽  
Foliar Application ◽  
Creeping Bentgrass ◽  
Membrane Lipid ◽  
Membrane Stability ◽  
Turf Quality ◽  
Mda Content ◽  
Plant Metabolite

Heat stress symptoms in cool-season plants are characterized by loss of chlorophyll (Chl) and membrane stability, as well as oxidative damage. The objectives of this study were to determine whether foliar application of β-sitosterol, a naturally occurring plant metabolite, may promote heat tolerance by suppressing heat-induced leaf senescence as indicated by the maintenance of healthy turf quality (TQ), and Chl and membrane stability; and to determine its roles in regulating antioxidant metabolism in creeping bentgrass (Agrostis stolonifera). ‘Penncross’ plants were exposed to heat stress (35/30 °C day/night) optimal temperature conditions (nonstressed control, 22/17 °C day/night) for a duration of 28 days in environment-controlled growth chambers. Plants were foliar-treated with β-sitosterol (400 µM) or water only (untreated control) before heat stress, and at 7-day intervals through 28 days of heat stress. Plants treated with β-sitosterol had significantly greater TQ and Chl content, and significantly less electrolyte leakage (EL) than untreated controls at 21 and 28 days of heat stress. Application of β-sitosterol reduced malondialdehyde (MDA) content significantly at 21 and 28 days of heat stress, and promoted the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) from 14 through 28 days of heat stress. β-Sitosterol effectively improved heat tolerance through suppression of leaf senescence in creeping bentgrass exposed to heat stress in association with the alleviation of membrane lipid peroxidation and activation of the enzymatic antioxidant system.

Heat acclimation in rats: modulation via lipid polyunsaturation

2002 ◽  
Vol 283 (2) ◽  
pp. R389-R399 ◽  
Author(s):  
Hilary Shmeeda ◽  
Pavel Kaspler ◽  
Judith Shleyer ◽  
Reuma Honen ◽  
Michal Horowitz ◽  
...  
Keyword(s):  
Heat Stress ◽  
Salivary Glands ◽  
Lipid Composition ◽  
Heat Acclimation ◽  
Membrane Lipid ◽  
Membrane Lipid Composition ◽  
Cholesterol Levels ◽  
Acute Heat Stress ◽  
Acyl Chains

Heat acclimation of rats has been shown to enhance endurance of rat hearts to ischemic insult and acute heat stress. Common protective features have been shown to be operative during both these stress-inducing conditions. To explore the role of membrane lipid composition in the adaptive response, we analyzed two major parameters that impact membrane dynamics and order, the nonesterified cholesterol levels and the acyl chain composition of phospholipids, in rat heart and salivary glands, both major thermoregulatory organs, in short- and long-term heat-acclimated rats. Before exposure to heat, control salivary gland tissue has a higher cholesterol-to-phospholipid mole ratio (0.32 ± 0.02) than heart (0.14 ± 0.01), and the acyl chains of its phospholipids are 50% more saturated. The remodeling strategies of the tissues after exposure to heat differed. Heart cholesterol levels increased after short-term heat acclimation (∼50%), whereas salivary gland cholesterol levels decreased in acute heat stress and long-term heat acclimation (∼32%). Remodeling of phospholipid acyl chains, particularly an increase in docosahexaenoic acid, was a protective strategy in both tissues (57% in heart and >100% in salivary glands). Modifying membrane lipid composition by treating rats with liposomes composed of egg phosphatidylcholine (PC) before exposure to heat resulted in a 38% increase in endurance to thermal stress. The density and affinity of muscarinic receptors of submaxillary salivary glands, involved in the acclimation response, were measured in control and PC liposome-treated rats, and then both groups were subjected to short-term heat acclimation. After PC treatment the well-established compensatory upregulation of the muscarinic receptors and concomitant decrease in their affinity was blunted. The substantial increase in the thermal endurance of heat-challenged intact rats after treatment with PC liposomes (600 vs. 200 min) suggests that membrane lipid composition plays a role in the ability of these tissues to respond to heat stress.

scholarly journals Transcriptional Basis for Differential Thermosensitivity of Seedlings of Various Tomato Genotypes

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 655
Author(s):  
Yangjie Hu ◽  
Sotirios Fragkostefanakis ◽  
Enrico Schleiff ◽  
Stefan Simm
Keyword(s):  
Transcription Factors ◽  
Heat Stress ◽  
Stress Response ◽  
Elevated Temperatures ◽  
Heat Stress Response ◽  
Atp Production ◽  
Different Temperatures ◽  
Related Plant ◽  
Shock Proteins ◽  
Tomato Genotypes

Transcriptional reprograming after the exposure of plants to elevated temperatures is a hallmark of stress response which is required for the manifestation of thermotolerance. Central transcription factors regulate the stress survival and recovery mechanisms and many of the core responses controlled by these factors are well described. In turn, pathways and specific genes contributing to variations in the thermotolerance capacity even among closely related plant genotypes are not well defined. A seedling-based assay was developed to directly compare the growth and transcriptome response to heat stress in four tomato genotypes with contrasting thermotolerance. The conserved and the genotype-specific alterations of mRNA abundance in response to heat stress were monitored after exposure to three different temperatures. The transcripts of the majority of genes behave similarly in all genotypes, including the majority of heat stress transcription factors and heat shock proteins, but also genes involved in photosynthesis and mitochondrial ATP production. In turn, genes involved in hormone and RNA-based regulation, such as auxin- and ethylene-related genes, or transcription factors like HsfA6b, show a differential regulation that associates with the thermotolerance pattern. Our results provide an inventory of genes likely involved in core and genotype-dependent heat stress response mechanisms with putative role in thermotolerance in tomato seedlings.

scholarly journals iTRAQ-Based Quantitative Proteomic Analysis of Heat Stress-Induced Mechanisms in Pepper Seedlings

2020 ◽  
Author(s):  
Jing Wang ◽  
Chengliang Liang ◽  
Sha Yang ◽  
Jingshuang Song ◽  
Xuefeng Li ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Heat Tolerance ◽  
Proteomic Analysis ◽  
Molecular Mechanisms ◽  
Negative Impact ◽  
Growth And Yield ◽  
Vegetable Crops ◽  
Heat Stress Response ◽  
Quantitative Proteomic Analysis

Abstract Background: As one of the most important vegetable crops, pepper has rich nutritional value and high economic value. Increasing heat stress due to the global warming has a negative impact on the growth and yield of pepper. Result: In the present study, we investigated the changes of phenotype, physiology, and proteome in heat-tolerant (17CL30) and heat-sensitive (05S180) pepper seedlings in response to heat stress. Phenotypic and physiological changes showed that 17CL30 had a stronger ability to resist heat stress compared with 05S180. In proteomic analysis, a total of 3,874 proteins were identified, and 1,591 proteins were considered to participate in the process of heat stress response. According to bioinformatic analysis of heat-responsive proteins, the heat tolerance of 17CL30 might be related to a higher photosynthesis, signal transduction, carbohydrate metabolism, and stress defense, compared with 05S180. Conclusion: To understand the heat stress response mechanism of pepper, an iTRAQ-based quantitative proteomic analysis was employed to identify possible heat-responsive proteins and metabolic pathways in 17CL30 and 05S180 pepper seedlings under heat stress. This study provided new insights into the molecular mechanisms involved in heat tolerance of pepper and might offer supportive reference for the breeding of new pepper variety with heat resistance.

scholarly journals Responses of terrestrial polar arthropods to high and increasing temperatures

2021 ◽  
Vol 224 (7) ◽  
Author(s):  
Simon Bahrndorff ◽  
Jannik M. S. Lauritzen ◽  
Mathias H. Sørensen ◽  
Natasja K. Noer ◽  
Torsten N. Kristensen
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Current Knowledge ◽  
The Arctic ◽  
Polar Regions ◽  
Evolutionary Adaptation ◽  
Thermal Plasticity ◽  
Terrestrial Arthropods ◽  
Physiological Adjustments

ABSTRACT Terrestrial arthropods in the Arctic and Antarctic are exposed to extreme and variable temperatures, and climate change is predicted to be especially pronounced in these regions. Available ecophysiological studies on terrestrial ectotherms from the Arctic and Antarctic typically focus on the ability of species to tolerate the extreme low temperatures that can occur in these regions, whereas studies investigating species plasticity and the importance of evolutionary adaptation to periodically high and increasing temperatures are limited. Here, we provide an overview of current knowledge on thermal adaptation to high temperatures of terrestrial arthropods in Arctic and Antarctic regions. Firstly, we summarize the literature on heat tolerance for terrestrial arthropods in these regions, and discuss variation in heat tolerance across species, habitats and polar regions. Secondly, we discuss the potential for species to cope with increasing and more variable temperatures through thermal plasticity and evolutionary adaptation. Thirdly, we summarize our current knowledge of the underlying physiological adjustments to heat stress in arthropods from polar regions. It is clear that very little data are available on the heat tolerance of arthropods in polar regions, but that large variation in arthropod thermal tolerance exists across polar regions, habitats and species. Further, the species investigated show unique physiological adjustments to heat stress, such as their ability to respond quickly to increasing or extreme temperatures. To understand the consequences of climate change on terrestrial arthropods in polar regions, we suggest that more studies on the ability of species to cope with stressful high and variable temperatures are needed.

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