Arabidopsis basic leucine zipper proteins that mediate stress-responsive abscisic acid signaling.
The phytohormone abscisic acid (ABA) plays an essential role in adaptive stress responses. The hormone regulates, among others, the expression of numerous stress-responsive genes. From various promoter analyses, ABA-responsive elements (ABREs) have been determined and a number of ABRE binding factors have been isolated, although their in vivo roles are not known. Here we report that the ABRE binding factors ABF3 and ABF4 function in ABA signaling. The constitutive overexpression of ABF3 or ABF4 in Arabidopsis resulted in ABA hypersensitivity and other ABA-associated phenotypes. In addition, the transgenic plants exhibited reduced transpiration and enhanced drought tolerance. At the molecular level, altered expression of ABA/stress-regulated genes was observed. Furthermore, the temporal and spatial expression patterns of ABF3 and ABF4 were consistent with their suggested roles. Thus, our results provide strong in vivo evidence that ABF3 and ABF4 mediate stress-responsive ABA signaling.
Kang
Joung-youn
JY
Kumho Life and Environmental Science Laboratory, Korea Kumho Petrochemical Co., Ltd., Kwangju 500-712, South Korea.
Choi
Hyung-in
HI
Im
Min-young
MY
Kim
Soo Young
SY
D000040:Abscisic Acid / Q000235:genetics / Q000494:pharmacology*; D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D050976:Basic-Leucine Zipper Transcription Factors; D002241:Carbohydrates / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics; D051790:G-Box Binding Factors; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D016350:Leucine Zippers / Q000235:genetics*; D010641:Phenotype; D010937:Plant Growth Regulators / Q000235:genetics / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D018526:Plant Transpiration / Q000187:drug effects; D030821:Plants, Genetically Modified; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics; D014867:Water / Q000494:pharmacology; D016335:Zinc Fingers / Q000235:genetics
D050976:Basic-Leucine Zipper Transcription Factors; D002241:Carbohydrates; D004268:DNA-Binding Proteins; D051790:G-Box Binding Factors; D010937:Plant Growth Regulators; D014157:Transcription Factors; D014867:Water; D012965:Sodium Chloride; D000040:Abscisic Acid