Functional analysis of an Arabidopsis heat-shock transcription factor HsfA3 in the transcriptional cascade downstream of the DREB2A stress-regulatory system.
A transcription factor DREB2A functions as a key regulator not only in drought stress responses but also in heat stress (HS) responses, and activates expression of many abiotic stress-responsive-genes involved in drought and HS tolerance. HsfA3 is one of the most up-regulated heat-inducible genes in transgenic plants overexpressing DREB2A. In this study, the analyses of HsfA3 expression profile and the transactivation analysis of HsfA3 showed that the expression of HsfA3 was directly regulated by DREB2A under HS. Microarray analysis using transgenic plants overexpressing HsfA3 also showed that overexpression of HsfA3 induces many heat-inducible genes. Furthermore, we showed that thermotolerance of the HsfA3 overexpressors was increased, and that of the hsfA3 T-DNA tagged mutants was decreased. These results indicate that HsfA3 regulates expression of many heat-inducible genes in the transcriptional cascade downstream of the DREB2A stress-regulatory system and functions in acquisition of thermotolerance under the control of the DREB2A cascade.
Yoshida
Takumi
T
Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Sakuma
Yoh
Y
Todaka
Daisuke
D
Maruyama
Kyonoshin
K
Qin
Feng
F
Mizoi
Junya
J
Kidokoro
Satoshi
S
Fujita
Yasunari
Y
Shinozaki
Kazuo
K
Yamaguchi-Shinozaki
Kazuko
K
D029681:Arabidopsis Proteins / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000502:physiology*; D018869:Heat-Shock Response / Q000502:physiology*; D018384:Oxidative Stress / Q000235:genetics; D010940:Plant Proteins / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology*
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C114579:DREB2A protein, Arabidopsis; C000620136:HSFA3 protein, Arabidopsis; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D014157:Transcription Factors