Arabidopsis heat shock transcription factor A2 as a key regulator in response to several types of environmental stress

Abstract

SummaryWe isolated 76 high-light and heat-shock (HL þ HS) stress-inducible genes, including a putative heat-shock transcription factor (HsfA2), by suppression-subtractive hybridization from Arabidopsis. The transcript level of HsfA2 was significantly increased under the several stress conditions or by the H 2 O 2 treatment. Furthermore, the induction of HsfA2 expression was highest among those of other class A HSFs in response to HL þ HS stress conditions. The promoter assay revealed that HsfA2 is induced mainly in rosette leaves under HL þ HS stress conditions. In the HsfA2-overexpressing Arabidopsis (Pro 35S :HsfA2) plants, 46 genes, including a large number of heat-shock proteins, ascorbate peroxidase 2 and galactinol synthase 1 and 2, were highly expressed compared with those in the wild-type plants. The transcript levels of the HsfA2 target genes are highly correlated with those of HsfA2 in the Pro 35S :HsfA2 plants. The transcript levels of the HsfA2 target genes, as well as HsfA2 transcripts, were induced by treating with exogenous H 2 O 2 . In the knockout HsfA2 Arabidopsis plants, the induction of 26 HsfA2 target genes was strongly reduced for up to 2 h under HL þ HS stress conditions. Furthermore, the Pro 35S :HsfA2 plants showed increased tolerance to combined environmental stresses. Our present results indicate that HsfA2 is a key regulator in the induction of the defence system under several types of environmental stress.

The Heat-Inducible Transcription Factor HsfA2 Enhances Anoxia Tolerance in Arabidopsis

“…3A). Interestingly, several putative HsfA2 targets (Nishizawa et al, 2006;Schramm et al, 2006) are also induced by anoxia (Fig. 3B).…”

“…Interestingly, it seems that in Arabidopsis, different from tomato (Solanum lycopersicum; Mishra et al, 2002), there is not a unique master regulator for the Hsf-mediated heat shock response. Different Hsfs have been identified as potential crucial element for Arabidopsis response not only to heat stress (Busch et al, 2005;Schramm et al, 2006Schramm et al, , 2008Charng et al, 2007) but also to oxidative stress (Li et al, 2005;Nishizawa et al, 2008), hydrogen peroxide (H 2 O 2 ), high light (Nishizawa et al, 2006), and salt stress as well (Ogawa et al, 2007).…”

Identification of recognition sequence of ANAC078 protein by the cyclic amplification and selection of targets technique

“…We previously isolated a gene encoding a NAC transcription factor named ANAC078 according to the nomenclature established for the Arabidopsis NAC family 11,12 though it has also been designated NTL11. 13 Furthermore, we reported that the transcript levels of 166 genes in ANAC078-overexpressing Arabidopsis plants (Ox-ANAC078) are increased compared with those in the wild-type plants under HL.…”

SALT-RESPONSIVE ERF1 Regulates Reactive Oxygen Species-Dependent Signaling during the Initial Response to Salt Stress in Rice

“…In addition, targets of MAPK proteins are mainly TFs (Popescu et al, 2009), underlining the direct connection with the MAPK signal cascade. The expression of many TF genes, including members of the HSF, WRKY, C 2 H 2 zinc-finger, bZIP, MYB, and AP2/ERF families, has been shown to be H 2 O 2 induced (Miao et al, 2004;Nishizawa et al, 2006;Davletova et al, 2005;Sun et al, 2010;Yun et al, 2010). Several zinc-finger proteins (ZFPs) contribute to salt tolerance by modulating oxidative stress responses.…”