scholarly journals Gut microbiota of Drosophila subobscura contributes to its heat tolerance but is sensitive to transient thermal stress

2021 ◽  
Author(s):  
Angelica Jaramillo ◽  
Luis E. Castaneda
Keyword(s):  
Heat Stress ◽  
Gut Microbiota ◽  
Heat Tolerance ◽  
Extinction Risk ◽  
Climatic Conditions ◽  
Drosophila Subobscura ◽  
Highly Sensitive ◽  
Transient Thermal ◽  
Structural Levels ◽  
The Impact

Global warming impacts animal fitness, leading to increasing extinction risk in ectotherm species. Gut microbiota can contribute to host physiology leading to an increase of resistance to abiotic stress conditions. Temperature has profound effects on ectotherms and gut microbiota can influence cold and heat tolerance of ectotherm species. Additionally, the gut microbiota is sensitive to environmental temperature, which induces changes in its composition and diversity. Here, we investigated the role of the gut microbiota on heat tolerance of Drosophila subobscura comparing the knockdown time between conventional and axenic, and we also assessed the impact of heat stress on the diversity and community structure of the gut microbiota, comparing non-stressed and heat-stressed flies. Our findings provide evidence that gut microbiota influences heat tolerance, and that heat stress modifies the gut microbiota at taxonomical and structural levels. These results demonstrate that gut microbiota contributes to heat tolerance but it is also highly sensitive to transient heat stress, which could have important effects on host fitness, population risk extinction, and vulnerability of ectotherms to current and future climatic conditions.

scholarly journals Gut Microbiota of Drosophila subobscura Contributes to Its Heat Tolerance and Is Sensitive to Transient Thermal Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Angélica Jaramillo ◽  
Luis E. Castañeda
Keyword(s):  
Heat Stress ◽  
Community Structure ◽  
Thermal Stress ◽  
Gut Microbiota ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Drosophila Subobscura ◽  
Transient Thermal ◽  
The Impact

The gut microbiota can contribute to host physiology leading to an increase of resistance to abiotic stress conditions. For instance, temperature has profound effects on ectotherms, and the role of the gut microbiota on the thermal tolerance of ectotherms is a matter of recent research. However, most of these studies have been focused on single static temperatures instead of evaluating thermal tolerance in a wide range of stressful temperatures. Additionally, there is evidence supporting that the gut microbiota is sensitive to environmental temperature, which induces changes in its composition and diversity. These studies have evaluated the effects of thermal acclimation (>2 weeks) on the gut microbiota, but we know little about the impact of transient thermal stress on the composition and diversity of the gut microbiota. Thus, we investigated the role of the gut microbiota on the heat tolerance of Drosophila subobscura by measuring the heat tolerance of conventional and axenic flies exposed to different heat stressful temperatures (35, 36, 37, and 38°C) and estimating the heat tolerance landscape for both microbiota treatments. Conventional flies exposed to mild heat conditions exhibited higher thermal tolerance than axenic flies, whereas at higher stressful temperatures there were no differences between axenic and conventional flies. We also assessed the impact of transient heat stress on the taxonomical abundance, diversity, and community structure of the gut microbiota, comparing non-stressed flies (exposed to 21°C) and heat-stressed flies (exposed to 34°C) from both sexes. Bacterial diversity indices, bacterial abundances, and community structure changed between non-stressed and heat-stressed flies, and this response was sex-dependent. In general, our findings provide evidence that the gut microbiota influences heat tolerance and that heat stress modifies the gut microbiota at the taxonomical and structural levels. These results demonstrate that the gut microbiota contributes to heat tolerance and is also highly sensitive to transient heat stress, which could have important consequences on host fitness, population risk extinction, and the vulnerability of ectotherms to current and future climatic conditions.

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 Effect of age at first calving and heat stress at parturition on reproductive efficiency and postpartum disorders in Holstein heifers

2019 ◽  
Vol 17 (2) ◽  
pp. e0405
Author(s):  
Miguel Mellado ◽  
Vanessa Alba ◽  
Leticia Gaytán ◽  
José E. García ◽  
Jesús Mellado
Keyword(s):  
Heat Stress ◽  
Age Groups ◽  
Dairy Farm ◽  
Climatic Conditions ◽  
Conception Rate ◽  
Age At First Calving ◽  
Hot Climate ◽  
Postpartum Disorders ◽  
Humidity Index ◽  
The Impact

The objective of this study was to evaluate the impact of age at first calving (AFC) and climatic conditions at calving on peripartum disorders and reproductive performance in Holstein heifers in a hot environment. A total of 3000 reproductive records from a large highly technified dairy farm were used; the variables evaluated were temperature humidity index (THI; <77, 77-83, >83) at calving and AFC (<2.0, 2.0-2.2 and >2.2 years). Across age groups, the cases of dystocic parturition increased (p<0.05) when the deliveries occurred with severe heat stress (4.3% vs. 3.3% for THI >83 and <83 units, respectively). Across THI, conception rate at the first postpartum artificial insemination (AI) was lower (p=0.02) for heifers calving for the first time >2.2 years compared to heifers calving between 2.0 and 2.2 and <2.0 years (9.8, 15.3 and 13.7%, respectively). Conception rate at first AI postcalving was higher (p<0.01) in heifers calving with THI less than 83 units than in heifers calving with a THI >83 units (16.8 vs. 5.4%). The conception rate considering all services was affected (p<0.05) by AFC (42.7, 50.4 and 40.9% for AFC <2.0, 2.0-2.2 and >2.2 years, respectively). The interaction AFC × THI at calving was significant (p<0.05). The occurrence of metritis was higher (p<0.05) in heifers <2.0 years of age at calving than those calving after 2 years of age. The presence of ovarian cysts was less common (p<0.05) in heifers with greater AFC. In conclusion, increasing the AFC in Holstein heifers had no benefits in reproduction and health, compared with heifers calving at <2.0 years. These data in a hot climate suggest that heifers should be selected to begin their first lactation before 2 years of age.

scholarly journals Thermotolerance and Physiological Traits as Fast Tools to Heat Tolerance Selection in Experimental Sugarcane Genotypes

Agriculture ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 251
Author(s):  
Sergio Castro-Nava ◽  
Enrique López-Rubio
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Cell Injury ◽  
Field Testing ◽  
Breeding Program ◽  
Field Conditions ◽  
High Yield ◽  
Temperature Stresses ◽  
Highly Sensitive ◽  
Membrane Thermostability

Heat stress limits the growth, development, and yield of crop plants when it occurs during short or long periods of time. An experiment was conducted with the objectives of (i) evaluating the cell membrane thermostability (CMT) as an indicator of heat tolerance in sugarcane and to determine its relationship with physiological parameters under heat-stressed conditions, and (ii) evaluating the utility of CMT for selecting heat-tolerant genotypes in a breeding program. A total of nine elite experimental, and four commercial sugarcane genotypes were evaluated for CMT, and the results are expressed as relative cell injury (RCI). Six genotypes were classified as highly tolerant and seven as highly sensitive. We concluded that the use of RCI, as an indicator of CMT in sugarcane genotypes, is a suitable useful parameter for selecting the genotypes tolerant to heat stress in a breeding program. This procedure, combined with other characters, helps to identify sugarcane plants with the ability to maintain a high yield photosynthetic rate under stressful field conditions. Furthermore, it offers an opportunity to improve selection efficiency over that of field testing, since high temperature stresses do not occur consistently under field conditions.

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 The Impact of Heat Load on Cattle

Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 322 ◽  
Author(s):  
Angela M. Lees ◽  
Veerasamy Sejian ◽  
Andrea L. Wallage ◽  
Cameron C. Steel ◽  
Terry L. Mader ◽  
...  
Keyword(s):  
Heat Stress ◽  
Cold Stress ◽  
Heat Load ◽  
Thermal Environment ◽  
Negative Impact ◽  
Negative Influence ◽  
Climatic Conditions ◽  
Worldwide Phenomenon ◽  
Hot Weather ◽  
The Impact

Heat stress and cold stress have a negative influence on cattle welfare and productivity. There have been some studies investigating the influence of cold stress on cattle, however the emphasis within this review is the influence of heat stress on cattle. The impact of hot weather on cattle is of increasing importance due to the changing global environment. Heat stress is a worldwide phenomenon that is associated with reduced animal productivity and welfare, particularly during the summer months. Animal responses to their thermal environment are extremely varied, however, it is clear that the thermal environment influences the health, productivity, and welfare of cattle. Whilst knowledge continues to be developed, managing livestock to reduce the negative impact of hot climatic conditions remains somewhat challenging. This review provides an overview of the impact of heat stress on production and reproduction in bovines.

scholarly journals Review of the impact of heat stress on reproductive performance of sheep

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
William H. E. J. van Wettere ◽  
Karen L. Kind ◽  
Kathryn L. Gatford ◽  
Alyce M. Swinbourne ◽  
Stephan T. Leu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Resource Use ◽  
Significant Proportion ◽  
Significant Risk ◽  
Field Studies ◽  
Climatic Conditions ◽  
Embryo Survival ◽  
Sheep Population ◽  
Temperature Controlled ◽  
The Impact

AbstractHeat stress significantly impairs reproduction of sheep, and under current climatic conditions is a significant risk to the efficiency of the meat and wool production, with the impact increasing as global temperatures rise. Evidence from field studies and studies conducted using environmental chambers demonstrate the effects of hot temperatures (≥ 32 °C) on components of ewe fertility (oestrus, fertilisation, embryo survival and lambing) are most destructive when experienced from 5 d before until 5 d after oestrus. Temperature controlled studies also demonstrate that ram fertility, as measured by rates of fertilisation and embryo survival, is reduced when mating occurs during the period 14 to 50 d post-heating. However, the contribution of the ram to heat induced reductions in flock fertility is difficult to determine accurately. Based primarily on temperature controlled studies, it is clear that sustained exposure to high temperatures (≥ 32 °C) during pregnancy reduces lamb birthweight and will, therefore, decrease lamb survival under field conditions. It is concluded that both ewe and ram reproduction is affected by relatively modest levels of heat stress (≥ 32 °C) and this is a concern given that a significant proportion of the global sheep population experiences heat stress of this magnitude around mating and during pregnancy. Despite this, strategies to limit the impacts of the climate on the homeothermy, behaviour, resource use and reproduction of extensively grazed sheep are limited, and there is an urgency to improve knowledge and to develop husbandry practices to limit these impacts.

Identification of best temperature humidity index model for assessing impact of heat stress on milk constituent traits in Murrah buffaloes under subtropical climatic conditions of Northern India

2017 ◽  
Author(s):  
Rajalaxmi Behera ◽  
A. K. Chakravarty ◽  
A. Sahu ◽  
N. Kashyap ◽  
S. Rai ◽  
...  
Keyword(s):  
Heat Stress ◽  
Least Squares ◽  
Milk Composition ◽  
Climatic Conditions ◽  
Index Model ◽  
Monthly Average ◽  
Temperature Humidity Index ◽  
Murrah Buffaloes ◽  
Humidity Index ◽  
The Impact

The present study was conducted to identify the most suitable temperature humidity index (THI) model among seven reported THI models for analyzing the impact of thermal stress on monthly test day fat % (MTDF%),monthly test day SNF% (MTSNF%), monthly test day fat yield (MTDFY) and monthly test day SNF yield (MTDSNFY) of Murrah buffaloes at subtropical climatic conditions of Karnal, India. A total of 8868 MTDF% and 8606 MTDSNF% records from 1107 lactational records of Murrah buffaloes under five parities were included in the present study and weather information on dry bulb temperature (Tdb), wet bulb temperature (Twb) and relative humidity (RH in %) for the corresponding period of 20 years (March 1994- December 2013) were collected from ICAR-NDRI and ICAR-CSSRI, Karnal, respectively. The overall least-squares means for MTDF% ranged from 7.71 ± 0.067 in TD1 to 8.10 ± 0.08 in TD 9 and MTDSNF% ranged from 9.61 ± 0.01 in TD5 and TD 6 to 9.65 ± 0.01 in TD 8. The overall least squares means of MTDFY (g) ranged from 411.23 ± 14.74 to 745.98 ± 13.57 while for MTDSNFY (g) the value ranged from 491.90 ± 17.21 to 922.16 ± 15.17. Monthly average THI was computed for each of the seven models. The lowest monthly average THI value was found in January, while either May, June or July showed the highest average THI value for all seven THI models. Regression analysis was performed for identifying the best THI to assess the impact of heat stress on milk constituent traits under study anda negative association was found between the milk constituent traits and monthly average THI values.The THI model[THI = (0.55 × Tdb + 0.2 × Tdp) × 1.8 + 32 + 17.5]developed by NRC(1971)was identified as the most suitable THI model to assess the impact of heat stress on milk composition traits of Murrah indicating maximum decline in MTDF% (-0.005), MTDFY (-0.68 g),MTDSNF% (b=-0.0008) and MTDSNFY (-2.25 g) per unit rise in THI.

Instant Insights: Heat stress in dairy cattle

2020 ◽  
Keyword(s):  
Heat Stress ◽  
Dairy Cattle ◽  
Animal Health ◽  
Climatic Conditions ◽  
Sub Saharan Africa ◽  
Production Traits ◽  
Smallholder Dairy ◽  
Sub Saharan ◽  
Economic Constraints ◽  
The Impact

This specially curated collection features four reviews of current and key research on heat stress in dairy cattle. The first chapter outlines technologies to breed for more heat tolerant dairy cattle, exploiting either between or within breed genetic variation in the trait. It discusses future perspectives on the use of different tools to achieve accelerated improvements of this important trait. The second chapter discusses breeding goals and multi-trait selection to balance production and non-production traits. It considers newer breeding objectives such as ensuring that cattle can adapt to a changing climate, including breeding for heat tolerance. The third chapter reviews challenges facing smallholder dairy farmers in Asia. These include the impact of high temperatures and humidity on milk yield, reproductive efficiency and animal health. The chapter places these challenges in the context of the broader economic constraints faced by smallholders and how they can be overcome. The final chapter highlights constraints in improving smallholder dairy production in Sub-Saharan Africa. Issues include developing breeds balancing yield with resilience to local climatic conditions. The chapter reviews ways of Improving breeding and productivity, as well as broader organisational support.

scholarly journals Interactions between developmental and adult acclimation have distinct consequences for heat-tolerance and heat-stress recovery

2021 ◽  
Author(s):  
Quentin Willot ◽  
Ben Loos ◽  
John S. Terblanche
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Climatic Conditions ◽  
Distinct Pattern ◽  
Recovery Rates ◽  
Relative Contribution ◽  
Heat Hardening ◽  
Full Factorial Experimental Design ◽  
Post Stress

Developmental and adult thermal acclimation can have distinct, even opposite, effects on adult heat resistance in ectotherms. Yet, their relative contribution to heat-hardiness of ectotherms remains unclear despite the broad ecological implications thereof. Furthermore, the deterministic relationship between heat-knockdown and recovery from heat stress is poorly understood but significant for establishing causal links between climate variability and population dynamics. Here, using D. melanogaster in a full-factorial experimental design, we assess flies heat-tolerance in static stress assays, and document how developmental and adult acclimation interact with a distinct pattern to promote survival to heat-stress in adults. We show that warmer adult acclimation is the initial factor enhancing survival to constant stressful high temperatures in flies, but also that the interaction between adult and developmental acclimation becomes gradually more important to ensure survival as the stress persists. This provides an important framework revealing the dynamic interplay between these two forms of acclimation, that ultimately enhance thermal tolerance as a function of stress duration. Furthermore, by investigating recovery rates post-stress, we also show that the process of heat-hardening and recovery post heat knockdown are likely to be based on set of (at least partially) divergent mechanisms. This could bear ecological significance as a tradeoff may exist between increasing thermal tolerance and maximizing recovery rates post-stress, constraining population responses when exposed to variable and stressful climatic conditions.

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