Heat shock transcription factor A1b regulates heat tolerance in wheat and Arabidopsis through
            OPR
            3 and jasmonate signalling pathway

Clematis plants play an important role in botanical gardens. Heat stress can destroy the activity, state and conformation of plant proteins, and its regulatory pathway has been well characterized in Arabidopsis and some crop plants. However, the heat resistance response mechanism in horticultural plants including Clematis has rarely been reported. Here, we identified a heat-tolerant clematis species, Clematis vitalba. The relative water loss and electrolytic leakage were significantly lower under heat treatment in Clematis vitalba compared to Stolwijk Gold. Differential expression heat-tolerant genes (HTGs) were identified based on nonparametric transcriptome analysis. For validation, one heat shock transcription factor, CvHSF30-2, extremely induced by heat stimuli in Clematis vitalba, was identified to confer tolerance to heat stress in Escherichia coli and Saccharomyces cerevisiae. Furthermore, silencing of HSF30-2 by virus-induced gene silencing (VIGS) led to heat sensitivity in tobacco and Clematis, suggesting that the candidate heat-resistant genes identified in this RNA-seq analysis are credible and offer significant utility. We also found that CvHSF30-2 improved heat tolerance of Clematis vitalba by elevating heat shock protein (HSP) expression, which was negatively regulated by CvHSFB2a. Taken together, this study provides insights into the mechanism of Clematis heat tolerance and the findings can be potentially applied in horticultural plants to improve economic efficiency through genetic approaches.

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Cloning of potato heat shock transcription factor <italic>StHsfA3</italic> gene and its functional analysis in heat tolerance

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2021.04114 ◽

2020 ◽

Vol 47 (4) ◽

pp. 672-683

Author(s):

Rui-Min TANG ◽

Xiao-Yun JIA ◽

Wen-Jiao ZHU ◽

Jing-Ming YIN ◽

Qing YANG

Keyword(s):

Functional Analysis ◽

Transcription Factor ◽

Heat Shock ◽

Heat Tolerance ◽

Heat Shock Transcription Factor

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Activation of the DNA-binding ability of human heat shock transcription factor 1 may involve the transition from an intramolecular to an intermolecular triple-stranded coiled-coil structure.

Molecular and Cellular Biology ◽

10.1128/mcb.14.11.7557 ◽

1994 ◽

Vol 14 (11) ◽

pp. 7557-7568 ◽

Cited By ~ 126

Author(s):

J Zuo ◽

R Baler ◽

G Dahl ◽

R Voellmy

Keyword(s):

Transcription Factor ◽

Heat Stress ◽

Heat Shock ◽

Dna Binding ◽

Hydrophobic Interactions ◽

Coiled Coil ◽

Heat Shock Transcription Factor ◽

Single Amino Acid ◽

Binding Ability ◽

Heat Shock Element

Heat stress regulation of human heat shock genes is mediated by human heat shock transcription factor hHSF1, which contains three 4-3 hydrophobic repeats (LZ1 to LZ3). In unstressed human cells (37 degrees C), hHSF1 appears to be in an inactive, monomeric state that may be maintained through intramolecular interactions stabilized by transient interaction with hsp70. Heat stress (39 to 42 degrees C) disrupts these interactions, and hHSF1 homotrimerizes and acquires heat shock element DNA-binding ability. hHSF1 expressed in Xenopus oocytes also assumes a monomeric, non-DNA-binding state and is converted to a trimeric, DNA-binding form upon exposure of the oocytes to heat shock (35 to 37 degrees C in this organism). Because endogenous HSF DNA-binding activity is low and anti-hHSF1 antibody does not recognize Xenopus HSF, we employed this system for mapping regions in hHSF1 that are required for the maintenance of the monomeric state. The results of mutagenesis analyses strongly suggest that the inactive hHSF1 monomer is stabilized by hydrophobic interactions involving all three leucine zippers which may form a triple-stranded coiled coil. Trimerization may enable the DNA-binding function of hHSF1 by facilitating cooperative binding of monomeric DNA-binding domains to the heat shock element motif. This view is supported by observations that several different LexA DNA-binding domain-hHSF1 chimeras bind to a LexA-binding site in a heat-regulated fashion, that single amino acid replacements disrupting the integrity of hydrophobic repeats render these chimeras constitutively trimeric and DNA binding, and that LexA itself binds stably to DNA only as a dimer but not as a monomer in our assays.

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