Nuclear Gene Encoding the Iron-Sulfur Subunit of Mitochondrial Complex II Is Regulated by B3 Domain Transcription Factors during Seed Development in Arabidopsis

• Published in: Plant physiology (Bethesda) Vol. 150; no. 1; pp. 84 - 95
• Main Authors: Roschzttardtz, Hannetz, Fuentes, Ignacia, Vásquez, Marcos, Corvalán, Claudia, León, Gabriel, Gómez, Isabel, Araya, Alejandro, Holuigue, Loreto, Vicente-Carbajosa, Jesús, Jordana, Xavier
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.05.2009; Oxford University Press ; American Society of Plant Biologists
• Subjects: Arabidopsis; Arabidopsis - embryology; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis Proteins - physiology; Base Sequence; Binding Sites; Bioenergetics and Photosynthesis; Biological and medical sciences; Dehydrogenases; DNA; DNA probes; Embryos; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Gene Expression Regulation, Plant; Genes; Germination; Germination - genetics; Iron-Sulfur Proteins; Iron-Sulfur Proteins - chemistry; Iron-Sulfur Proteins - genetics; Iron-Sulfur Proteins - metabolism; Life Sciences; Microbiology and Parasitology; Molecular Sequence Data; Plant physiology and development; Plants; Promoter Regions, Genetic; Protein Structure, Tertiary; Protein Subunits; Protein Subunits - chemistry; Protein Subunits - genetics; Protein Subunits - metabolism; Seed development; Seeds; Seeds - genetics; Seeds - growth & development; Seeds - metabolism; Succinate Dehydrogenase; Succinate Dehydrogenase - chemistry; Succinate Dehydrogenase - genetics; Succinate Dehydrogenase - metabolism; Transcription Factors; Transcription Factors - chemistry; Transcription Factors - physiology; Seeds; Iron; Subunit; Arabidopsis thaliana; Mitochondria; Gene; Plant physiology; Cruciferae; Dicotyledones; Angiospermae; Development; Spermatophyta; Experimental plant; Transcription factor; Sulfur
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.109.136531

Mitochondrial complex II (succinate dehydrogenase) is part of the tricarboxylic acid cycle and the respiratory chain. Three nuclear genes encode its essential iron-sulfur subunit in Arabidopsis (Arabidopsis thaliana). One of them, SUCCINATE DEHYDROGENASE2-3 (SDH2-3), is specifically expressed in the embryo during seed maturation, suggesting that SDH2-3 may have a role as the complex II iron-sulfur subunit during embryo maturation and/or germination. Here, we present data demonstrating that three abscisic acid-responsive elements and one RY-like enhancer element, present in the SDH2-3 promoter, are involved in embryo-specific SDH2-3 transcriptional regulation. Furthermore, we show that ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEAFY COTYLEDON2, three key B3 domain transcription factors involved in gene expression during seed maturation, control SDH2-3 expression. Whereas ABI3 and FUS3 interact with the RY element in the SDH2-3 promoter, the abscisic acid-responsive elements are shown to be a target for bZIP53, a member of the basic leucine zipper (bZIP) family of transcription factors. We show that group S1 bZIP53 protein binds the promoter as a heterodimer with group C bZIP10 or bZIP25. To the best of our knowledge, the SDH2-3 promoter is the first embryo-specific promoter characterized for a mitochondrial respiratory complex protein. Characterization of succinate dehydrogenase activity in embryos from two homozygous sdh2-3 mutant lines permits us to conclude that SDH2-3 is the major iron-sulfur subunit of mature embryo complex II. Finally, the absence of SDH2-3 in mutant seeds slows down their germination, pointing to a role of SDH2-3-containing complex II at an early step of germination.