Heat stress response in plants: a complex game with chaperones and more than twenty heat stress transcription factors

Abstract

Compared to the overall multiplicity of more than 20 plant Hsfs, detailed analyses are mainly restricted to tomato and Arabidopsis and to three important representatives of the family (Hsfs A1, A2 and B1). The three Hsfs represent examples of striking functional diversification specialized for the three phases of the heat stress (hs) response (triggering, maintenance and recovery). This is best illustrated for the tomato Hsf system: (i) HsfA1a is the master regulator responsible for hs-induced gene expression including synthesis of HsfA2 and HsfB1. It is indispensible for the development of thermotolerance. (ii) Although functionally equivalent to HsfA1a, HsfA2 is exclusively found after hs induction and represents the dominant Hsf, the "working horse" of the hs response in plants subjected to repeated cycles of hs and recovery in a hot summer period. Tomato HsfA2 is tightly integrated into a network of interacting proteins (HsfA1a, Hsp17-CII, Hsp17-CI) influencing its activity and intracellular distribution. (iii) Because of structural peculiarities, HsfB1 acts as coregulator enhancing the activity of HsfA1a and/or HsfA2. But in addition, it cooperates with yet to be identified other transcription factors in maintaining and/or restoring housekeeping gene expression.

Controlled Expression of Recombinant Proteins in Physcomitrella patens by a Conditional Heat-shock Promoter: a Tool for Plant Research and Biotechnology

“…The data presented demonstrate that the molecular mechanism of the heat-shock response is highly conserved between bryophytes and spermatophytes. For promoters of sHSPs, optimal induction temperatures, dose-dependent responses and kinetics of protein expression were similar in P. patens, A. thaliana and Tomato (Baniwal et al, 2004) (for a review see (Nover et al, 2001)). In Table 1, the reporter activities driven by the soybean hsp17.3B promoter were compared to that driven by other constitutive and inducible promoters tested in P. patens.…”

Proteomics-based analysis reveals that Verticillium dahliae toxin induces cell death by modifying the synthesis of host proteins

“…2, a6) are involved in the regulation of protein function and location in plants (Acconcia et al 2009). The ubiquitin/26S proteasome system is involved in plant-microbe interactions and plant defense (Dielen et al 2010), and most HSPs have strong cytoprotective effects and ensure plant homeostasis (Baniwal et al 2004). Transitional endoplasmic reticulum ATPase (TER ATPase) (Fig.…”

OsHsfA2c and OsHsfB4b are involved in the transcriptional regulation of cytoplasmic OsClpB (Hsp100) gene in rice (Oryza sativa L.)

“…According to Bjork and Sistonen (2010), a negative feedback loop operates as evidenced by interactions between human Hsf1 and Hsps (such as Hsp70/Hsp40 and Hsp90) as well as by the fact that Hsps keep Hsf1 in an inactive form under non-stress conditions. Interactions among CI and CII Hsps, Hsp70 and Hsp90 proteins with specific Hsfs have been reported (Baniwal et al 2004;Lee et al 1995;NishizawaYokoi et al 2010;Yamada and Nishimura 2008). The feedback control mechanism in Arabidopsis is considered to involve Hsp70 as a negative regulator of Hsfs (Lee et al 1995).…”