The heat shock factor family fromTriticum aestivumin response to heat and other major abiotic stresses and their role in regulation of heat shock protein genes

Abstract

Heat shock factors (Hsfs) play a central regulatory role in acquired thermotolerance. To understand the role of the major molecular players in wheat adaptation to heat stress, the Hsf family was investigated in Triticum aestivum. Bioinformatic and phylogenetic analyses identified 56 TaHsf members, which are classified into A, B, and C classes. Many TaHsfs were constitutively expressed. Subclass A6 members were predominantly expressed in the endosperm under non-stress conditions. Upon heat stress, the transcript levels of A2 and A6 members became the dominant Hsfs, suggesting an important regulatory role during heat stress. Many TaHsfA members as well as B1, C1, and C2 members were also up-regulated during drought and salt stresses. The heat-induced expression profiles of many heat shock protein (Hsp) genes were paralleled by those of A2 and A6 members. Transactivation analysis revealed that in addition to TaHsfA members (A2b and A4e), overexpression of TaHsfC2a activated expression of TaHsp promoter-driven reporter genes under non-stress conditions, while TaHsfB1b and TaHsfC1b did not. Functional heat shock elements (HSEs) interacting with TaHsfA2b were identified in four TaHsp promoters. Promoter mutagenesis analysis demonstrated that an atypical HSE (GAACATTTTGGAA) in the TaHsp17 promoter is functional for heat-inducible expression and transactivation by Hsf proteins. The transactivation of Hsp promoter-driven reporter genes by TaHsfC2a also relied on the presence of HSE. An activation motif in the C-terminal domain of TaHsfC2a was identified by amino residue substitution analysis. These data demonstrate the role of HsfA and HsfC2 in regulation of Hsp genes in wheat.

Genome-wide analysis, expression profile of heat shock factor gene family (CaHsfs) and characterisation of CaHsfA2 in pepper (Capsicum annuum L.)

“…3). A similar situation was found in other plants, like Arabidopsis (A1-type Hsfs ) [55], apple ( MdHsfA1a , A1d , B1a and B1b ) [50], wheat ( A1 and A8 groups, and some A2 and A6 group members) [41]. The tissue- and stage-specific expression patterns of pepper CaHsf family genes, such as CaHsfA1b in root, CaHsfB3a in PL-16DPA, CaHsfB5 in PC-B10, and CaHsfC1 in leaf and PL-B5, indicated that CaHsfs might be widely involved in the development of various organs and tissues, which is helpful to further understanding the functions of CaHsf genes in pepper developmental biology [56].…”

“…Notably, five out of seven members of class CaHsfB, especially B1 and B5, were significantly up-regulated by HS in R9 leaves, which was in accord with the HsfB1 and B2 groups in wheat [41]. Most HsfBs, except HsfB5, contain the tetrapeptide LFGV in the C-terminal domain, which is assumed to function as a repressor motif in the transcriptional machinery [8].…”

“…The Hsf gene family has, so far, been fully characterised only in a few model species, such as Arabidopsis , rice, maize, wheat and Chinese cabbage [8, 20, 39–41]. The genome sequence of pepper has been published recently [42, 43], which enables the characterisation of the pepper Hsf family and their responses to various stresses at the molecular level.…”

Insilico Analysis of cis acting Regulatory Elements CAREs in Upstream Regions of Ascorbate Glutathione Pathway Genes from Oryza sativa

“…Genes involved in these mechanisms contain HSE motifs that bind heat shock factors (HSFs), and are up-regulated during heat stress. HSE have been found to be consistently conserved in the regulatory regions of many heat induced genes [30]. The presence of a HSE motif in the 1.0 kbp regulatory regions of all rice Asc-Glu genes may imply the ability of the genes to survive high temperature stress condition or the participation or need during high temperature stress condition and ensure protection of cellular homeostasis.…”

Identification of heat shock proteins via transcriptome profiling of tree peony leaf exposed to high temperature

“…One of the most important thermotolerance mechanisms in plants is the induction of heat shock proteins (Hsps), which typically act as molecular chaperones to reduce damage to cells (Wang et al, 2004;Xue et al, 2014). Based on their molecular weights, plant Hsps are divided into 5 groups, including Hsp100, Hsp90, Hsp70, Hsp60, and the small Hsp (sHsp) family (Wang et al, 2004).…”