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1.
Pak J Biol Sci ; 25(6): 516-530, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36098187

RESUMO

<b>Background and Objective:</b> Late sowing of wheat exposes the anthesis and grain filling stages of the crop to a terminal heat temperature stress Therefore, detecting putative QTL associated with grain yield and its attributes and identifying the most tolerant genotypes to terminal drought and heat stress across environments will be beneficial in wheat breeding programs. <b>Materials and Methods:</b> In the present study, among 49 CIMMYT wheat lines evaluated for yield and stability in eight environments, we selected the highest ten high-yielding (HYL) and the lowest ten low yielding lines (LYL) along with three wheat check cultivars (CC) for screening with eighteen previously published SSR molecular markers associated with drought and heat stress tolerance. <b>Results:</b> Two SSR markers (BARC126 and BARC11) on 7D were associated with delay heading dates under normal and late sowing dates. Likewise, the SSR markers WMC396, GWM537 and XGWM577 which were mapped on 7B, were significantly linked with grain yield-related traits under one/or both sowing dates, most of them showed desirable effects, indicating terminal heat stress tolerance. Different SSR markers viz., BARC11, XGWM132 and GWM537 showed pleiotropic effects. <b>Conclusion:</b> The SSR markers BARC186-5A, XGWM132-6B, WMC396-7B, XGWM577-7B and GWM165-4B were more prominently associated with heat tolerance by showing a desirable performance of grain yield-related traits under late sowing or across environments, some of these desirable alleles were corresponding to previously QTL in various genotypes that could be valuable in breeding for high-yield in wheat.


Assuntos
Termotolerância , Triticum , Grão Comestível/genética , Resposta ao Choque Térmico/genética , Melhoramento Vegetal , Termotolerância/genética , Triticum/genética
2.
Sci Rep ; 12(1): 14831, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050336

RESUMO

Wheat, one of the most widely consumed staple food crops globally, is relatively vulnerable to high temperature-induced heat stress. It is therefore essential to gain more insight into the comprehensive mechanism of thermotolerance of wheat in order to safeguard its production. In view of this, we analysed heat stress responsive transcriptome data of wheat to determine its gene expression level under heat stress. A total of 7990 DEGs, including 4483 up-regulated and 3507 down regulated genes were identified. Gene Ontology (GO) analysis categorized 3910 DEGs into different ontology families. 146 pathways involving 814 DEGs were enriched during KEGG analysis. Metabolic pathways and biosynthesis of secondary metabolites were the major pathways enriched. MYB (myeloblastosis) transcription factors (TFs) and many other TFs as bHLH, WRKY, NAC, ERF, were determined to be quite abundant in the DEGs. Since various reports indicate that these TFs play important role in plants abiotic stress, it is an indication that our DEGs are functional in heat stress tolerance. Verification of few selected DEGs using RT-qPCR produced expression levels similar to the transcriptome data. This indicates that the transcriptome data is reliable. These results could be helpful in enhancing our understanding of the mechanism underlying thermotolerance in wheat.


Assuntos
Termotolerância , Triticum , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genótipo , Humanos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Termotolerância/genética , Transcriptoma , Triticum/genética , Triticum/metabolismo
3.
Nat Commun ; 13(1): 4513, 2022 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-35922443

RESUMO

Predicting how reef-building corals will respond to accelerating ocean warming caused by climate change requires knowledge of how acclimation and symbiosis modulate heat tolerance in coral early life-history stages. We assayed transcriptional responses to heat in larvae and juveniles of 11 reproductive crosses of Acropora tenuis colonies along the Great Barrier Reef. Larvae produced from the warmest reef had the highest heat tolerance, although gene expression responses to heat were largely conserved by cross identity. Juvenile transcriptional responses were driven strongly by symbiosis - when in symbiosis with heat-evolved Symbiodiniaceae, hosts displayed intermediate expression between its progenitor Cladocopium and the more stress tolerant Durusdinium, indicating the acquisition of tolerance is a conserved evolutionary process in symbionts. Heat-evolved Symbiodiniaceae facilitated juvenile survival under heat stress, although host transcriptional responses to heat were positively correlated among those hosting different genera of Symbiodiniaceae. These findings reveal the relative contribution of parental environmental history as well as symbiosis establishment in coral molecular responses to heat in early life-history stages.


Assuntos
Antozoários , Dinoflagelados , Termotolerância , Animais , Antozoários/genética , Recifes de Corais , Dinoflagelados/genética , Expressão Gênica , Larva , Simbiose/genética , Termotolerância/genética
4.
J Antibiot (Tokyo) ; 75(9): 509-513, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35918479

RESUMO

The thermotolerant strain Streptomyces sp. HR41 was found to produce compound 1 only in a 45 °C culture, and not at the standard temperature. We previously designated this type of compound as a "heat shock metabolite" (HSM). NMR and MS analytical techniques were used to determine that the chemical structure of 1 comprised a methylated-oxazole ring and a linear chain moiety modified with a terminal amide group. Thus, 1 was shown to be a new curromycin analog, which we have designated noaoxazole (1). Compound 1 weakly activated Notch signal reporter activity without exhibiting cytotoxicity against assay cells at the same concentration.


Assuntos
Streptomyces , Termotolerância , Resposta ao Choque Térmico , Oxazóis/metabolismo , Streptomyces/metabolismo
5.
Genes (Basel) ; 13(8)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-36011264

RESUMO

The availability of large-scale genomic data resources makes it very convenient to mine and analyze genes that are related to important agricultural traits in rice. Pan-genomes have been constructed to provide insight into the genome diversity and functionality of different plants, which can be used in genome-assisted crop improvement. Thus, a pan-genome comprising all genetic elements is crucial for comprehensive variation study among the heat-resistant and -susceptible rice varieties. In this study, a rice pan-genome was firstly constructed by using 45 heat-tolerant and 15 heat-sensitive rice varieties. A total of 38,998 pan-genome genes were identified, including 37,859 genes in the reference and 1141 in the non-reference contigs. Genomic variation analysis demonstrated that a total of 76,435 SNPs were detected and identified as the heat-tolerance-related SNPs, which were specifically present in the highly heat-resistant rice cultivars and located in the genic regions or within 2 kbp upstream and downstream of the genes. Meanwhile, 3214 upregulated and 2212 downregulated genes with heat stress tolerance-related SNPs were detected in one or multiple RNA-seq datasets of rice under heat stress, among which 24 were located in the non-reference contigs of the rice pan-genome. We then mapped the DEGs with heat stress tolerance-related SNPs to the heat stress-resistant QTL regions. A total of 1677 DEGs, including 990 upregulated and 687 downregulated genes, were mapped to the 46 heat stress-resistant QTL regions, in which 2 upregulated genes with heat stress tolerance-related SNPs were identified in the non-reference sequences. This pan-genome resource is an important step towards the effective and efficient genetic improvement of heat stress resistance in rice to help meet the rapidly growing needs for improved rice productivity under different environmental stresses. These findings provide further insight into the functional validation of a number of non-reference genes and, especially, the two genes identified in the heat stress-resistant QTLs in rice.


Assuntos
Oryza , Termotolerância , Genes de Plantas , Oryza/genética , Locos de Características Quantitativas/genética , Termotolerância/genética , Transcriptoma
6.
Appl Microbiol Biotechnol ; 106(17): 5415-5431, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35941254

RESUMO

Both the increasing environmental temperature in nature and the defensive body temperature response to pathogenic fungi during mammalian infection cause heat stress during the fungal existence, reproduction, and pathogenic infection. To adapt and respond to the changing environment, fungi initiate a series of actions through a perfect thermal response system, conservative signaling pathways, corresponding transcriptional regulatory system, corresponding physiological and biochemical processes, and phenotypic changes. However, until now, accurate response and regulatory mechanisms have remained a challenge. Additionally, at present, the latest research progress on the heat resistance mechanism of pathogenic fungi has not been summarized. In this review, recent research investigating temperature sensing, transcriptional regulation, and physiological, biochemical, and morphological responses of fungi in response to heat stress is discussed. Moreover, the specificity thermal adaptation mechanism of pathogenic fungi in vivo is highlighted. These data will provide valuable knowledge to further understand the fungal heat adaptation and response mechanism, especially in pathogenic heat-resistant fungi. KEY POINTS: • Mechanisms of fungal perception of heat pressure are reviewed. • The regulatory mechanism of fungal resistance to heat stress is discussed. • The thermal adaptation mechanism of pathogenic fungi in the human body is highlighted.


Assuntos
Fungos , Termotolerância , Adaptação Fisiológica , Animais , Resposta ao Choque Térmico , Humanos , Mamíferos , Transdução de Sinais
7.
Nat Commun ; 13(1): 4790, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35970904

RESUMO

Phenotypic plasticity is an important ecological and evolutionary response for organisms experiencing environmental change, but the ubiquity of this capacity within coral species and across symbiont communities is unknown. We exposed ten genotypes of the reef-building coral Montipora capitata with divergent symbiont communities to four thermal pre-exposure profiles and quantified gene expression before stress testing 4 months later. Here we show two pre-exposure profiles significantly enhance thermal tolerance despite broadly different expression patterns and substantial variation in acclimatization potential based on coral genotype. There was no relationship between a genotype's basal thermal sensitivity and ability to acquire heat tolerance, including in corals harboring naturally tolerant symbionts, which illustrates the potential for additive improvements in coral response to climate change. These results represent durable improvements from short-term stress hardening of reef-building corals and substantial cryptic complexity in the capacity for plasticity.


Assuntos
Antozoários , Termotolerância , Aclimatação/genética , Animais , Antozoários/genética , Mudança Climática , Recifes de Corais , Simbiose/genética , Termotolerância/genética
8.
Proc Biol Sci ; 289(1981): 20220872, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-36043280

RESUMO

Coral reefs are facing unprecedented mass bleaching and mortality events due to marine heatwaves and climate change. To avoid extirpation, corals must adapt. Individual variation in heat tolerance and its heritability underpin the potential for coral adaptation. However, the magnitude of heat tolerance variability within coral populations is largely unresolved. We address this knowledge gap by exposing corals from a single reef to an experimental marine heatwave. We found that double the heat stress dosage was required to induce bleaching in the most-tolerant 10%, compared to the least-tolerant 10% of the population. By the end of the heat stress exposure, all of the least-tolerant corals were dead, whereas the most-tolerant remained alive. To contextualize the scale of this result over the coming century, we show that under an ambitious future emissions scenario, such differences in coral heat tolerance thresholds equate to up to 17 years delay until the onset of annual bleaching and mortality conditions. However, this delay is limited to only 10 years under a high emissions scenario. Our results show substantial variability in coral heat tolerance which suggests scope for natural or assisted evolution to limit the impacts of climate change in the short-term. For coral reefs to persist through the coming century, coral adaptation must keep pace with ocean warming, and ambitious emissions reductions must be realized.


Assuntos
Antozoários , Termotolerância , Aclimatação , Animais , Antozoários/genética , Mudança Climática , Recifes de Corais
9.
Microbiol Res ; 263: 127138, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35931002

RESUMO

Current technology that enables bioethanol production from agricultural biomass imposes harsh conditions for Saccharomyces cerevisiae's metabolism. In this work, the genetic architecture of industrial bioethanol yeast strain SA-1 was evaluated. SA-1 segregant FMY097 was previously described as highly aldehyde resistant and here also as thermotolerant: two important traits for the second-generation industry. A Quantitative Trait Loci (QTL) mapping of 5-hydroxymethylfurfural (HMF) -resistant segregants of hybrid FMY097/BY4742 disclosed a region in chromosome II bearing alleles with uncommon non-synonymous (NS) single nucleotide polymorphisms (SNPs) in FMY097: MIX23, PKC1, SEA4, and SRO77. Allele swap to susceptible laboratory strain BY4742 revealed that SEA4FMY097 enhances robustness towards HMF, but the industrial fitness could not be fully recovered. The genetic network arising from the causative genes in the QTL window suggests that intracellular signaling TOR (Target of Rapamycin) and CWI (Cell Wall Integrity) pathways are regulators of this phenotype in FMY097. Because the QTL mapping did not result in one major allelic contribution to the evaluated trait, a background effect in FMY097's HMF resistance is expected. Quantification of NADPH - cofactor implied in endogenous aldehyde detoxification reactions - supports the former hypothesis, given its high availability in FMY097. Regarding thermotolerance, SEA4FMY097 grants BY4742 ability to grow in temperatures as high as 38 ºC in liquid, while allele PKC1FMY097 allows growth up to 40 ºC in solid medium. Both SEA4FMY097 and PKC1FMY097 encode rare NS SNPs, not found in other > 1013S. cerevisiae. Altogether, these findings point towards crucial membrane and stress mediators for yeast robustness.


Assuntos
Proteínas de Saccharomyces cerevisiae , Termotolerância , Furaldeído/análogos & derivados , Redes Reguladoras de Genes , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Termotolerância/genética
10.
Sci Rep ; 12(1): 13965, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35978081

RESUMO

High-temperature ethanol fermentation by thermotolerant yeast is considered a promising technology for ethanol production, especially in tropical and subtropical regions. In this study, optimization conditions for high-temperature ethanol fermentation of pineapple waste hydrolysate (PWH) using a newly isolated thermotolerant yeast, Saccharomyces cerevisiae HG1.1, and the expression of genes during ethanol fermentation at 40 °C were carried out. Three independent variables, including cell concentration, pH, and yeast extract, positively affected ethanol production from PWH at 40 °C. The optimum levels of these significant factors evaluated using response surface methodology (RSM) based on central composite design (CCD) were a cell concentration of 8.0 × 107 cells/mL, a pH of 5.5, and a yeast extract concentration of 4.95 g/L, yielding a maximum ethanol concentration of 36.85 g/L and productivity of 3.07 g/L. Gene expression analysis during high-temperature ethanol fermentation using RT-qPCR revealed that the acquisition of thermotolerance ability and ethanol fermentation efficiency of S. cerevisiae HG1.1 are associated with genes responsible for growth and ethanol stress, oxidative stress, acetic acid stress, DNA repair, the pyruvate-to-tricarboxylic acid (TCA) pathway, and the pyruvate-to-ethanol pathway.


Assuntos
Ananas , Termotolerância , Ananas/genética , Ananas/metabolismo , Etanol/metabolismo , Fermentação , Expressão Gênica , Piruvatos/metabolismo , Saccharomyces cerevisiae/metabolismo , Temperatura , Termotolerância/genética
11.
J Genet ; 1012022.
Artigo em Inglês | MEDLINE | ID: mdl-35975817

RESUMO

The reproductive stage in many crops, including maize, is very sensitive to heat stress and the genetic overlap between gametophytic and sporophytic phase gives an opportunity to select superior stress tolerant genotype at gametophytic stage. An attempt was made to evaluate the response of cyclic pollen selection in the F1 and F2 generations on the performance of F3 generation progenies for seed yield and yield contributing traits under natural heat stress conditions. In this direction three groups of F3 progenies, namely (i) pollen selection in F1 and F2 generations (GG), (ii) pollen selection only in F2 generation (CG), (iii) no pollen selection in F1 and F2 generations (CC) were screened for heat stress at Agricultural Research Station (ARS), Bheemarayanagudi. The GG progenies recorded significantly higher chlorophyll content, more number of pollen grains per anther and less pollen sterility compared to CG and CC group of progenies under heat stress. Further, the F4 progenies obtained through cyclic pollen selection (in F1, F2 and F3) were also tested for heat stress tolerance at seedling stage. The significant improvement for heat stress tolerance was recorded in F4 progenies derived through cyclic pollen selection as compared to control (no pollen selection for heat tolerance in any generation) F4 progenies. The results indicated that cyclic pollen selection in F1, F2 and F3 generations improved the heat stress tolerance of the progenies in the succeeding generations. To provide genetic evidence for the effect of pollen selection for heat tolerance, the control F2 (C) and selected F2 (G) populations were compared for the segregation of SSR markers. The selected F2 (G) population showed significant deviation from normal Mendelian ratio of 1:2:1 and showed skewness towards the alleles selected from male parent. The results provide strong evidence for an increase in the frequency of parental alleles in the progenies that impart heat stress tolerance.


Assuntos
Termotolerância , Zea mays , Genótipo , Pólen/genética , Sementes/genética , Termotolerância/genética , Zea mays/genética
12.
J Reprod Immunol ; 153: 103684, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35973294

RESUMO

The epithelial cell is the main basic unit of the udder in which milk synthesis takes place. Curcumin is well known for its antioxidant, anti-apoptotic, and anti- inflammatory properties. The present study was performed to test whether in vitro curcumin supplementation can alleviate the unfavorable impact of hyperthermia on buffalo mammary epithelial cells (BuMECs). The spontaneously immortalized BuMECs were divided into 7 groups (n = 9); 1) unstressed BuMECs (negative control, 37 °C); 2) BuMECs exposed to hyperthermia without curcumin treatment (positive control); 3-7) BuMECs cultured with different concentrations of curcumin (5, 10, 20, 40 and 60 µM), respectively, followed by hyperthermic exposure (42ºC) for 1 h and then returned to 37ºC. Changes in viability (MTT assay), proliferation (BrdU colorimetric immunoassay) and concentrations of antioxidant enzymes, CAT, and SOD (ELISA) of BuMECs were recorded. The gene expression study was performed using qRT-PCR. Lower concentrations of curcumin (5, 10 µM) maintained viability, enhanced proliferation, and content of antioxidant enzymes of heat stressed BuMECs. Curcumin induced thermotolerance and antioxidant status by upregulating the expression of antioxidants genes, anti-apoptotic genes and heat shock proteins in heat stressed BuMECs compared to the positive control group. Besides, curcumin reduced apoptosis and inflammation in BuMECs exposed to hyperthermia by downregulating the expression of genes and transcriptional factors associated with apoptosis and inflammatory immune response. The results reveal the potential roles of curcumin in eliminating the negative impact of hyperthermia on BuMECs by regulating the pathways of apoptosis, inflammation, and oxidative stress.


Assuntos
Curcumina , Termotolerância , Animais , Antioxidantes/metabolismo , Apoptose , Bromodesoxiuridina/metabolismo , Búfalos/metabolismo , Curcumina/metabolismo , Curcumina/farmacologia , Células Epiteliais/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Inflamação/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo
13.
J Dairy Sci ; 105(9): 7820-7828, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35879162

RESUMO

Heat stress has negative consequences for milk production and reproduction of dairy cattle. These adverse effects are likely to increase because of climate change and anticipated increases in milk yield. Some of the variation among cows in ability to resist effects of heat stress is genetic. The current objective of this observational study was to assess the effectiveness of the Australian breeding value for heat tolerance (ABVHT) based on the decline in milk yield with heat stress for predicting cow differences in effects of heat stress on regulation of body temperature, milk production, and reproductive function. Genomic breeding values for heat tolerance were calculated for 12,487 cows from a single California dairy farm. Rectal temperature in the afternoon (1100-2045 h) was measured on a subset of 626 lactating cows with ABVHT ≥102 (heat tolerant) or <102 (heat sensitive). Rectal temperature was 0.12°C lower for heat-tolerant cows than heat-sensitive cows. Vaginal temperatures were measured every 15 min for 5 d in 118 cows with ABVHT ≥108 (extreme heat tolerant) or <97 (extreme heat sensitive). Vaginal temperature was 0.07°C lower for extreme heat-tolerant cows than extreme heat-sensitive cows. Lactation records for 4,703 cows with ABVHT were used to evaluate seasonal variation in first 90-d milk yield, fat percent, and protein percent for each ABVHT quartile. Overall, cows with higher ABVHT had lower milk yield, fat percentage, and protein percentage and higher first service pregnancy rate. There was no summer depression in production or reproduction or interactions between season and ABVHT quartile. We observed that ABVHT can successfully identify heat-tolerant cows that maintain lower body temperatures during heat stress. The lack of a pronounced seasonality in milk production or reproduction precluded evaluation of whether ABVHT is related to the magnitude of effect of heat stress on those traits.


Assuntos
Transtornos de Estresse por Calor , Termotolerância , Animais , Austrália , Bovinos , Feminino , Transtornos de Estresse por Calor/metabolismo , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico , Temperatura Alta , Lactação , Leite/metabolismo , Gravidez
14.
Plant J ; 111(5): 1368-1382, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35781899

RESUMO

High temperature stress inhibits photosynthesis and threatens wheat production. One measure of photosynthetic heat tolerance is Tcrit - the critical temperature at which incipient damage to photosystem II (PSII) occurs. This trait could be improved in wheat by exploiting genetic variation and genotype-by-environment interactions (GEI). Flag leaf Tcrit of 54 wheat genotypes was evaluated in 12 thermal environments over 3 years in Australia, and analysed using linear mixed models to assess GEI effects. Nine of the 12 environments had significant genetic effects and highly variable broad-sense heritability (H2 ranged from 0.15 to 0.75). Tcrit GEI was variable, with 55.6% of the genetic variance across environments accounted for by the factor analytic model. Mean daily growth temperature in the month preceding anthesis was the most influential environmental driver of Tcrit GEI, suggesting biochemical, physiological and structural adjustments to temperature requiring different durations to manifest. These changes help protect or repair PSII upon exposure to heat stress, and may improve carbon assimilation under high temperature. To support breeding efforts to improve wheat performance under high temperature, we identified genotypes superior to commercial cultivars commonly grown by farmers, and demonstrated potential for developing genotypes with greater photosynthetic heat tolerance.


Assuntos
Complexo de Proteína do Fotossistema II , Termotolerância , Clorofila , Interação Gene-Ambiente , Fotossíntese/genética , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo , Melhoramento Vegetal , Triticum/fisiologia
15.
Int J Mol Sci ; 23(14)2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35887334

RESUMO

Durum wheat is strongly affected by climatic constraints such as high temperatures and drought, which frequently lead to yield reduction. Damages due to high temperatures are related to plant thermotolerance, a trait determined by two components: basal and acquired thermotolerance. In this study, the effect of drought and heat stress imposed singularly or sequentially was investigated in ten durum wheat cultivars (cvs) at the physiological and molecular level. The traits analyzed were cell membrane stability, relative water content, proline content, and expression level of several genes for heat shock proteins (HSPs). Our results indicate that drought priming can induce the acquisition of thermotolerance in most cultivars already classified as able to acquire thermotolerance by heat pre-treatment. Proline accumulation was correlated to cell membrane stability, meaning that the most thermotolerant cvs were able to accumulate higher levels of proline. Acquired thermotolerance is also due to the activation of HSP gene expression; similarly, pre-treatment with water stress was able to activate HSPs expression. The results reported indicate that water stress plays an important role in inducing thermotolerance, comparable to mild heat stress pre-treatment. This is the first report on the effect of drought stress on the acquisition of thermotolerance.


Assuntos
Secas , Termotolerância , Desidratação , Proteínas de Choque Térmico/metabolismo , Prolina/metabolismo , Estresse Fisiológico/genética , Triticum/metabolismo
16.
Nat Plants ; 8(7): 778-791, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35817823

RESUMO

High temperature is one of the major environmental stresses affecting plant growth and fitness. Heat stress transcription factors (HSFs) play critical roles in regulating the expression of heat-responsive genes. However, how HSFs are regulated remains obscure. Here, we show that ALBA4, ALBA5 and ALBA6, which phase separate into stress granules (SGs) and processing bodies (PBs) under heat stress, directly bind selected messenger RNAs, including HSF mRNAs, and recruit them into SGs and PBs to protect them from degradation under heat stress in Arabidopsis. The alba456 triple mutants, but not single and double mutants, display pleiotropic developmental defects and hypersensitivity to heat stress. Mutations in XRN4, a cytoplasmic 5' to 3' exoribonuclease, can rescue the observed developmental and heat-sensitive phenotypes of alba456 seedlings. Our study reveals a new layer of regulation for HSFs whereby HSF mRNAs are stabilized by redundant action of ALBA proteins in SGs and PBs for plant thermotolerance.


Assuntos
Arabidopsis , Termotolerância , Arabidopsis/metabolismo , Grânulos Citoplasmáticos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
17.
Plant Biotechnol J ; 20(9): 1819-1832, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35656643

RESUMO

Increasing populations and temperatures are expected to escalate food demands beyond production capacities, and the development of maize lines with better performance under heat stress is desirable. Here, we report that constitutive ectopic expression of a heterologous glutaredoxin S17 from Arabidopsis thaliana (AtGRXS17) can provide thermotolerance in maize through enhanced chaperone activity and modulation of heat stress-associated gene expression. The thermotolerant maize lines had increased protection against protein damage and yielded a sixfold increase in grain production in comparison to the non-transgenic counterparts under heat stress field conditions. The maize lines also displayed thermotolerance in the reproductive stages, resulting in improved pollen germination and the higher fidelity of fertilized ovules under heat stress conditions. Our results present a robust and simple strategy for meeting rising yield demands in maize and, possibly, other crop species in a warming global environment.


Assuntos
Arabidopsis , Termotolerância , Arabidopsis/genética , Grão Comestível/genética , Oxirredução , Termotolerância/genética , Zea mays/genética
18.
Int J Mol Sci ; 23(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35682701

RESUMO

Heat stress (HS) seriously restricts the growth and development of plants. When plants are exposed to extreme high temperature, the heat stress response (HSR) is activated to enable plants to survive. Sessile plants have evolved multiple strategies to sense and cope with HS. Previous studies have established that PHYTOCHROME INTERACTING FACTOR 4 (PIF4) acts as a key component in thermomorphogenesis; however, whether PIF4 regulates plant thermotolerance and the molecular mechanism linking this light transcriptional factor and HSR remain unclear. Here, we show that the overexpression of PIF4 indeed provides plants with a stronger basal thermotolerance and greatly improves the survival ability of Arabidopsis under severe HS. Via phylogenetic analysis, we identified two sets (six) of PIF4 homologs in wheat, and the expression patterns of the PIF4 homologs were conservatively induced by heat treatment in both wheat and Arabidopsis. Furthermore, the PIF4 protein was accumulated under heat stress and had an identical expression level. Additionally, we found that the core regulator of HSR, HEAT SHOCK TRANSCRIPTION FACTOR A2 (HSFA2), was highly responsive to light and heat. Followed by promoter analysis and ChIP-qPCR, we further found that PIF4 can bind directly to the G-box motifs of the HSFA2 promoter. Via effector-reporter assays, we found that PIF4 binding could activate HSFA2 gene expression, thereby resulting in the activation of other HS-inducible genes, such as heat shock proteins. Finally, the overexpression of PIF4 led to a stronger basal thermotolerance under non-heat-treatment conditions, thereby resulting in an enhanced tolerance to severe heat stress. Taken together, our findings propose that PIF4 is linked to heat stress signaling by directly binding to the HSFA2 promoter and triggering the HSR at normal temperature conditions to promote the basal thermotolerance. These functions of PIF4 provide a candidate direction for breeding heat-resistant crop cultivars.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Termotolerância , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição de Choque Térmico/genética , Temperatura Alta , Filogenia , Fitocromo/metabolismo , Melhoramento Vegetal , Proteínas de Plantas/genética , Termotolerância/genética
19.
Science ; 376(6599): 1293-1300, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35709289

RESUMO

How the plasma membrane senses external heat-stress signals to communicate with chloroplasts to orchestrate thermotolerance remains elusive. We identified a quantitative trait locus, Thermo-tolerance 3 (TT3), consisting of two genes, TT3.1 and TT3.2, that interact together to enhance rice thermotolerance and reduce grain-yield losses caused by heat stress. Upon heat stress, plasma membrane-localized E3 ligase TT3.1 translocates to the endosomes, on which TT3.1 ubiquitinates chloroplast precursor protein TT3.2 for vacuolar degradation, implying that TT3.1 might serve as a potential thermosensor. Lesser accumulated, mature TT3.2 proteins in chloroplasts are essential for protecting thylakoids from heat stress. Our findings not only reveal a TT3.1-TT3.2 genetic module at one locus that transduces heat signals from plasma membrane to chloroplasts but also provide the strategy for breeding highly thermotolerant crops.


Assuntos
Cloroplastos , Oryza , Proteínas de Plantas , Locos de Características Quantitativas , Termotolerância , Cloroplastos/genética , Cloroplastos/fisiologia , Genes de Plantas , Oryza/genética , Oryza/fisiologia , Melhoramento Vegetal/métodos , Proteínas de Plantas/genética , Termotolerância/genética
20.
Plant Mol Biol ; 110(1-2): 131-145, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35729482

RESUMO

KEY MESSAGE: Ethanol priming induces heat stress tolerance by the stimulation of unfolded protein response. Global warming increases the risk of heat stress-related yield losses in agricultural crops. Chemical priming, using safe agents, that can flexibly activate adaptive regulatory responses to adverse conditions, is a complementary approach to genetic improvement for stress adaptation. In the present study, we demonstrated that pretreatment of Arabidopsis with a low concentration of ethanol enhances heat tolerance without suppressing plant growth. We also demonstrated that ethanol pretreatment improved leaf growth in lettuce (Lactuca sativa L.) plants grown in the field conditions under high temperatures. Transcriptome analysis revealed a set of genes that were up-regulated in ethanol-pretreated plants, relative to water-pretreated controls. Binding Protein 3 (BIP3), an endoplasmic reticulum (ER)-stress marker chaperone gene, was among the identified up-regulated genes. The expression levels of BIP3 were confirmed by RT-qPCR. Root-uptake of ethanol was metabolized to organic acids, nucleic acids, amines and other molecules, followed by an increase in putrescine content, which substantially promoted unfolded protein response (UPR) signaling and high-temperature acclimation. We also showed that inhibition of polyamine production and UPR signaling negated the heat stress tolerance induced by ethanol pretreatment. These findings collectively indicate that ethanol priming activates UPR signaling via putrescine accumulation, leading to enhanced heat stress tolerance. The information gained from this study will be useful for establishing ethanol-mediated chemical priming strategies that can be used to help maintain crop production under heat stress conditions.


Assuntos
Arabidopsis , Termotolerância , Arabidopsis/metabolismo , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Etanol/farmacologia , Putrescina/metabolismo , Resposta a Proteínas não Dobradas
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