AtHSBP functions in seed development and the motif is required for subcellular localization and interaction with AtHSFs

214

155

Cell survival under high temperature conditions involves the activation of heat stress response (HSR), which in principle is highly conserved among different organisms, but shows remarkable complexity and unique features in plant systems. The transcriptional reprogramming at higher temperatures is controlled by the activity of the heat stress transcription factors (Hsfs). Hsfs allow the transcriptional activation of HSR genes, among which heat shock proteins (Hsps) are best characterized. Hsps belong to multigene families encoding for molecular chaperones involved in various processes including maintenance of protein homeostasis as a requisite for optimal development and survival under stress conditions. Hsfs form complex networks to activate downstream responses, but are concomitantly subjected to cell-type-dependent feedback regulation through factor-specific physical and functional interactions with chaperones belonging to Hsp90, Hsp70 and small Hsp families. There is increasing evidence that the originally assumed specialized function of Hsf/chaperone networks in the HSR turns out to be a complex central stress response system that is involved in the regulation of a broad variety of other stress responses and may also have substantial impact on various developmental processes. Understanding in detail the function of such regulatory networks is prerequisite for sustained improvement of thermotolerance in important agricultural crops.

Section: The Regulatory Network Of Hsfs Hsps and Co‐chaperonesmentioning

confidence: 98%

Prospects of engineering thermotolerance in crops through modulation of heat stress transcription factor and heat shock protein networks

Fragkostefanakis

Röth

Schleiff

et al. 2014

214

155

“…2004). Arabidopsis ( Arabidopsis thaliana ) HSF binding protein AtHSBP interacts with HSF to reduce HSF transactivation as a negative regulator during the attenuation of HS response (Hsu & Jinn 2010; Hsu, Lai & Jinn 2010). In addition, many HSFs and HSPs are involved in improving plant thermotolerance (Queitsch et al .…”

Section: Introductionmentioning

confidence: 99%

Heat shock‐induced biphasic Ca²⁺ signature and OsCaM1‐1 nuclear localization mediate downstream signalling in acquisition of thermotolerance in rice (Oryza sativa L.)

Luo

Vignols

et al. 2012

Self Cite

We investigated heat shock (HS)‐triggered Ca2+ signalling transduced by a Ca2+ sensor, calmodulin (CaM), linked to early transcriptome changes of HS‐responsive genes in rice. We observed a biphasic [Ca2+]cyt signature in root cells that was distinct from that in epicotyl and leaf cells, which showed a monophasic response after HS. Treatment with Ca2+ and A23187 generated an intense and sustained increase in [Ca2+]cyt in response to HS. Conversely, treatment with Ca2+ chelator, L‐type Ca2+ channel blocker and CaM antagonist, but not intracellular Ca2+ release inhibitor, strongly inhibited the increased [Ca2+]cyt. HS combined with Ca2+ and A23187 accelerated the expression of OsCaM1‐1 and sHSPC/N genes, which suggests that the HS‐induced apoplastic Ca2+ influx is responsible for the [Ca2+]cyt response and downstream HS signalling. In addition, the biphasic response of OsCaM1‐1 in the nucleus followed the Ca2+ signature, which may provide the information necessary to direct HS‐related gene expression. Overexpression of OsCaM1‐1 induced the expression of Ca2+/HS‐related AtCBK3, AtPP7, AtHSF and AtHSP at a non‐inducing temperature and enhanced intrinsic thermotolerance in transgenic Arabidopsis. Therefore, HS‐triggered rapid increases in [Ca2+]cyt, together with OsCaM1‐1 expression and its nuclear localization, are important in mediating downstream HS‐related gene expression for the acquisition of thermotolerance in rice.

“…Heat stress initiates conformational changes in HSFs, triggering trimer formation to bind to heat‐shock elements in HSPs promoters, inducing their transcription (Saidi et al, 2011). After heat stress cessation, the heat‐shock factor‐binding proteins (HSBPs) induce dissociation of the HSFs trimer into monomeric and inactive form, reducing HSP production and attenuating thermotolerance/HSR (Hsu & Jinn, 2010; Hsu, et al, 2010). HSBPs are negative regulators of the HSR; therefore, thermomemory may require inactivation of HSBP genes.…”

Section: Rice Somatic Abiotic Stress Memorymentioning

confidence: 99%

The role of priming and memory in rice environmental stress adaptation: Current knowledge and perspectives

Ganie,

McMulkin,

Devoto

2024

Plant responses to abiotic stresses are dynamic, following the unpredictable changes of physical environmental parameters such as temperature, water and nutrients. Physiological and phenotypical responses to stress are intercalated by periods of recovery. An earlier stress can be remembered as ‘stress memory’ to mount a response within a generation or transgenerationally. The ‘stress priming’ phenomenon allows plants to respond quickly and more robustly to stressors to increase survival, and therefore has significant implications for agriculture. Although evidence for stress memory in various plant species is accumulating, understanding of the mechanisms implicated, especially for crops of agricultural interest, is in its infancy. Rice is a major food crop which is susceptible to abiotic stresses causing constraints on its cultivation and yield globally. Advancing the understanding of the stress response network will thus have a significant impact on rice sustainable production and global food security in the face of climate change. Therefore, this review highlights the effects of priming on rice abiotic stress tolerance and focuses on specific aspects of stress memory, its perpetuation and its regulation at epigenetic, transcriptional, metabolic as well as physiological levels. The open questions and future directions in this exciting research field are also laid out.