ABI3 mediates expression of the peroxiredoxin antioxidant AtPER1 gene and induction by oxidative stress.
The peroxiredoxin antioxidant gene AtPER1 has been considered to be specifically expressed in the embryo and aleurone layer during maturation and desiccation stages of development, and in the mature seed, typically for late embryogenesis-abundant (lea) transcripts. In the abscisic acid-insensitive abi3-1 mutant, the AtPER1 transcript level is strongly reduced, suggesting ABI3 to be a prime regulator of AtPER1. We have studied the expression pattern and regulation of AtPER1 with a series of nine promoter::GUS constructs with deletions and/or mutations in putative regulatory elements. Arabidopsis lines harbouring these constructs revealed AtPER1 promoter activity in the endosperm, especially the chalazal cyst, already when the embryo is in the late globular stage, in the embryo from the late torpedo stage, and in distinct cells of unfertilized and fertilized ovules. Early expression seems to be dependent on a putative antioxidant-responsive promoter element (ARE), while from the bent cotyledon stage endosperm and embryo expression is dependent on an ABA-responsive element (ABRE) likely to bind ABI5. The shortest promoter fragment (113 bp), devoid of ARE, ABRE and without an intact RY/Sph element thought to bind ABI3 did not drive GUS expression. The AtPER1::GUS construct also revealed expression in cotyledons, meristems and stem branching points. In general, seed and vegetative expression coincided with the expression pattern of ABI3. In plants ectopically expressing ABI3, AtPER1::GUS expression was found in true leaves, and AtPER1 could be induced by exogenous ABA and oxidative stress (H2O2 and hydroquinone). ABI3-mediated oxidative stress induction was dependent on the presence of an intact ARE element.
Haslekås
Camilla
C
Division of Cell and Molecular Biology, Department of Biology, University of Oslo, P.O. Box 1031, Blindern, 0315 Oslo, Norway.
Grini
Paul E
PE
Nordgard
Silje H
SH
Thorstensen
Tage
T
Viken
Marte K
MK
Nygaard
Vigdis
V
Aalen
Reidunn B
RB
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006873:Hydroquinones / Q000494:pharmacology; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000502:physiology*; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012098:Reproduction / Q000235:genetics; D020218:Response Elements / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors
C091601:ABI3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D006873:Hydroquinones; C111227:Per1 protein, Arabidopsis; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D000040:Abscisic Acid; D006861:Hydrogen Peroxide; D010544:Peroxidases; D054464:Peroxiredoxins; D005966:Glucuronidase; C031927:hydroquinone