scholarly journals Patterns of thermotolerance, chlorophyll fluorescence, and heat shock gene expression vary among four Boechera species and Arabidopsis thaliana

Botany ◽  
2017 ◽  
Vol 95 (1) ◽  
pp. 9-27 ◽  
Author(s):  
Gillian Halter ◽  
Nicole Simonetti ◽  
Cristy Suguitan ◽  
Kenneth Helm ◽  
Jessica Soroksky ◽  
...  
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Heat Shock ◽  
Leaf Damage ◽  
Wild Plant ◽  
Heat Shock Gene ◽  
Acquired Thermotolerance ◽  
Genes Encoding

Thermotolerance is a property of all organisms, but owing to their sessile nature, this trait is particularly important in plants. Basal thermotolerance is based on inherent tolerance to heat stress. Acquired thermotolerance is attained through stress-induced gene expression, often of those genes encoding heat shock proteins (HSPs). Both basal and acquired thermotolerance have been extensively studied in model species such as Arabidopsis thaliana (L.) Heynh., but much less is known about thermotolerance in wild plant species. The aims of this study were to examine the basal and acquired thermotolerance of four species of Boechera, and of A. thaliana. Four species of Boechera native to California were collected and used for this study: B. arcuata (Nutt.) Windham & Al-Shehbaz, B. californica (Rollins) Windham & Al-Shehbaz, B. depauperata (A.Nelson & P.B.Kenn.) Windham & Al-Shehbaz, and B. perennans (S.Watson) W.A.Weber. Seedlings were exposed to both basal and acquired heat stress and then monitored for leaf damage, chlorophyll fluorescence, and gene expression of HsfA3, Hsp101, and four sHSP genes. Analysis of organismal responses to heat stress demonstrated that all four Boechera species are more thermotolerant than A. thaliana. Further we found that he species with the highest thermotolerance is B. depauperata.

scholarly journals Genetically Modified Heat Shock Protein90s and Polyamine Oxidases in Arabidopsis Reveal Their Interaction under Heat Stress Affecting Polyamine Acetylation, Oxidation and Homeostasis of Reactive Oxygen Species

Plants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 323 ◽  
Author(s):  
Imene Toumi ◽  
Marianthi G. Pagoulatou ◽  
Theoni Margaritopoulou ◽  
Dimitra Milioni ◽  
Kalliopi A. Roubelakis-Angelakis
Keyword(s):  
Reactive Oxygen Species ◽  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Heat Shock ◽  
Specific Inhibitor ◽  
Reactive Oxygen ◽  
Mrna Levels ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Genes Encoding

The chaperones, heat shock proteins (HSPs), stabilize proteins to minimize proteotoxic stress, especially during heat stress (HS) and polyamine (PA) oxidases (PAOs) participate in the modulation of the cellular homeostasis of PAs and reactive oxygen species (ROS). An interesting interaction of HSP90s and PAOs was revealed in Arabidopsis thaliana by using the pLFY:HSP90RNAi line against the four AtHSP90 genes encoding cytosolic proteins, the T-DNA Athsp90-1 and Athsp90-4 insertional mutants, the Atpao3 mutant and pharmacological inhibitors of HSP90s and PAOs. Silencing of all cytosolic HSP90 genes resulted in several-fold higher levels of soluble spermidine (S-Spd), acetylated Spd (N8-acetyl-Spd) and acetylated spermine (N1-acetyl-Spm) in the transgenic Arabidopsis thaliana leaves. Heat shock induced increase of soluble-PAs (S-PAs) and soluble hydrolyzed-PAs (SH-PAs), especially of SH-Spm, and more importantly of acetylated Spd and Spm. The silencing of HSP90 genes or pharmacological inhibition of the HSP90 proteins by the specific inhibitor radicicol, under HS stimulatory conditions, resulted in a further increase of PA titers, N8-acetyl-Spd and N1-acetyl-Spm, and also stimulated the expression of PAO genes. The increased PA titers and PAO enzymatic activity resulted in a profound increase of PAO-derived hydrogen peroxide (H2O2) levels, which was terminated by the addition of the PAO-specific inhibitor guazatine. Interestingly, the loss-of-function Atpao3 mutant exhibited increased mRNA levels of selected AtHSP90 genes. Taken together, the results herein reveal a novel function of HSP90 and suggest that HSP90s and PAOs cross-talk to orchestrate PA acetylation, oxidation, and PA/H2O2 homeostasis.

Transcriptional and translational regulation of major heat shock proteins and patterns of trehalose mobilization during hyperthermic recovery in repressed and derepressedSaccharomyces cerevisiae

1998 ◽  
Vol 44 (4) ◽  
pp. 341-350 ◽  
Author(s):  
Claudia Gross ◽  
Kenneth Watson
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Translational Regulation ◽  
De Novo ◽  
Recovery Period ◽  
Recovery Phase ◽  
Heat Shock Gene ◽  
Genes Encoding ◽  
Shock Proteins

Patterns of heat shock gene transcription and translation, as well as trehalose content, were investigated in both glucose (repressed) and acetate (derepressed) grown cells of Saccharomyces cerevisiae during heat shock and subsequent return of cells to 25°C. Heat-shocked cells (37°C for 30 min), grown in either glucose- or acetate-supplemented media, initially acquired high thermotolerance to a 50°C heat stress, which was progressively lost when cultures were allowed to recover at 25°C and subsequently exposed to a second heat stress. In all cases, with the notable exception of repressed cells of a relatively thermosensitive strain, inhibition of protein synthesis and coincident decrease in trehalose accumulation during the heat shock had little effect on the kinetics of loss of thermotolerance. Heat shock at 37°C elicited a marked increase in transcription and translation of genes encoding major heat shock proteins (hsps). During recovery at 25°C, both metabolic activities were suppressed followed by a gradual increase in hsp mRNA transcription to levels observed prior to heat shock. De novo translation of hsp mRNAs, however, was no longer observed during the recovery phase, although immuno- detection analyses demonstrated persistence of high levels of hsps 104, 90, 70, and 60 in cells throughout the 240-min recovery period. In addition, while heat shock induced trehalose was rapidly degraded during recovery in repressed cells, levels remained high in derepressed cells. Results therefore indicated that the progressive loss of induced thermotolerance exhibited by glucose- and acetate-grown cells was not closely correlated with levels of hsp or trehalose. It was concluded that both constitutive and de novo synthesized hsps require heat shock associated activation to confer thermotolerance and this modification is progressively reversed upon release from the heat-shocked state.Key words: thermotolerance, hyperthermic recovery, hsp transcription, hsp translation, trehalose.

Tissue specificity of expression of heat shock gene ATHSP70-10 in Arabidopsis thaliana seedlings under normal and stress conditions

2020 ◽  
Vol 2020 (3) ◽  
pp. 37-47
Author(s):  
L.Ye. Kozeko ◽  
◽  
E.L. Kordyum ◽  
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Shock ◽  
Water Deficit ◽  
Tissue Specificity ◽  
Abiotic Factors ◽  
Root Apex ◽  
Stress Conditions ◽  
Heat Shock Gene ◽  
Organ Specificity ◽  
Pcr Analysis

Mitochondrial heat shock proteins of HSP70 family support protein homeostasis in mitochondria under normal and stress conditions. They provide folding and complex assembly of proteins encoded by mitochondrial genome, as well as import of cytosolic proteins to mitochondria, their folding and protection against aggregation. There are reports about organ-specificity of mitochondrial HSP70 synthesis in plants. However, tissue specificity of their functioning remains incompletely characterized. This problem was studied for mitochondrial AtHSP70-10 in Arabidopsis thaliana seedlings using a transgenic line with uidA signal gene under normal conditions, as well as high temperature and water deficit. Under normal conditions, histochemical GUS-staining revealed the expression of AtHSP70-10 in cotyledon and leaf hydathodes, stipules, central cylinder in root differentiation and mature zones, as well as weak staining in root apex and root-shoot junction zone. RT-PCR analysis of wild-type seedlings exposed to 37°C showed rapid upregulation of AtHSP70-10, which reached the highest level within 2 h. In addition, the gradual development of water deficit for 5 days caused an increase in transcription of this gene, which became more pronounced after 3 days and reached a maximum after 5 days of dehydration. Histochemical analysis showed complete preservation of tissue localization of AtHSP70-10 expression under both abiotic factors. The data obtained indicate the specific functioning of mitochondrial chaperone AtHSP70-10 in certain plant cellular structures.

Insights into the heat-responsive transcriptional network of tomato contrasting genotypes

2021 ◽  
Vol 19 (1) ◽  
pp. 44-57
Author(s):  
Sirine Werghi ◽  
Charfeddine Gharsallah ◽  
Nishi Kant Bhardwaj ◽  
Hatem Fakhfakh ◽  
Faten Gorsane
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Candidate Genes ◽  
Expression Patterns ◽  
Response Strategies ◽  
Transcriptional Reprogramming ◽  
Genes Encoding ◽  
Breeding Programmes ◽  
Gene Transcripts ◽  
Resource Data

AbstractDuring recent decades, global warming has intensified, altering crop growth, development and survival. To overcome changes in their environment, plants undergo transcriptional reprogramming to activate stress response strategies/pathways. To evaluate the genetic bases of the response to heat stress, Conserved DNA-derived Polymorphism (CDDP) markers were applied across tomato genome of eight cultivars. Despite scattered genotypes, cluster analysis allowed two neighbouring panels to be discriminate. Tomato CDDP-genotypic and visual phenotypic assortment permitted the selection of two contrasting heat-tolerant and heat-sensitive cultivars. Further analysis explored differential expression in transcript levels of genes, encoding heat shock transcription factors (HSFs, HsfA1, HsfA2, HsfB1), members of the heat shock protein (HSP) family (HSP101, HSP17, HSP90) and ascorbate peroxidase (APX) enzymes (APX1, APX2). Based on discriminating CDDP-markers, a protein functional network was built allowing prediction of candidate genes and their regulating miRNA. Expression patterns analysis revealed that miR156d and miR397 were heat-responsive showing a typical inverse relation with the abundance of their target gene transcripts. Heat stress is inducing a set of candidate genes, whose expression seems to be modulated through a complex regulatory network. Integrating genetic resource data is required for identifying valuable tomato genotypes that can be considered in marker-assisted breeding programmes to improve tomato heat tolerance.

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