A distal ABA responsive element in AtNCED3 promoter is required for positive feedback regulation of ABA biosynthesis in Arabidopsis.
The plant hormone abscisic acid (ABA) plays a crucial role in plant development and responses to abiotic stresses. Recent studies indicate that a positive feedback regulation by ABA exists in ABA biosynthesis in plants under dehydration stress. To understand the molecular basis of this regulation, we analyzed the cis-elements of the AtNCED3 promoter in Arabidopsis. AtNCED3 encodes the first committed and highly regulated dioxygenase in the ABA biosynthetic pathway. Through delineated and mutagenesis analyses in stable-transformed Arabidopsis, we revealed that a distal ABA responsive element (ABRE: GGCACGTG, -2372 to -2364 bp) is required for ABA-induced AtNCED3 expression. By analyzing the AtNCED3 expression in ABRE binding protein ABF3 over-expression transgenic plants and knock-out mutants, we provide evidence that the ABA feedback regulation of AtNCED3 expression is not mediated by ABF3.
Institute of Plant Molecular Biology and Agricultural Biotechnology, State Key Lab of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Yan-Zhuo
YZ
Yang
Institute of Plant Molecular Biology and Agricultural Biotechnology, State Key Lab of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Bao-Cai
BC
Tan
D000040:Abscisic Acid / Q000096:biosynthesis*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics*; D025461:Feedback, Physiological / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D006651:Histocytochemistry; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010940:Plant Proteins / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020218:Response Elements / Q000235:genetics*; D017422:Sequence Analysis, DNA
C506773:ABF3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; D000040:Abscisic Acid; D049308:Dioxygenases; C109043:9-cis-epoxy-carotenoid dioxygenase