title: Characterization of the aldehyde dehydrogenase gene families of Zea mays and Arabidopsis.
abstract: Cytoplasmic male sterility is a maternally transmitted inability to produce viable pollen. Male sterility occurs in Texas (T) cytoplasm maize as a consequence of the premature degeneration of the tapetal cell layer during microspore development. This sterility can be overcome by the combined action of two nuclear restorer genes, rf1 and rf2a. The rf2a gene encodes a mitochondrial aldehyde dehydrogenase (ALDH) that is capable of oxidizing a variety of aldehydes. Six additional ALDH genes were cloned from maize and Arabidopsis. In vivo complementation assays and in vitro enzyme analyses demonstrated that all six genes encode functional ALDHs. Some of these ALDHs are predicted to accumulate in the mitochondria, others in the cytosol. The intron/exon boundaries of these genes are highly conserved across maize and Arabidopsis and between mitochondrial and cytosolic ALDHs. Although animal, fungal, and plant genomes each encode both mitochondrial and cytosolic ALDHs, it appears that either the gene duplications that generated the mitochondrial and the cytosolic ALDHs occurred independently within each lineage or that homogenizing gene conversion-like events have occurred independently within each lineage. All studied plant genomes contain two confirmed or predicted mitochondrial ALDHs. It appears that these mitochondrial ALDH genes arose via independent duplications after the divergence of monocots and dicots or that independent gene conversion-like events have homogenized the mitochondrial ALDH genes in the monocot and dicot lineages. A computation approach was used to identify amino acid residues likely to be responsible for functional differences between mitochondrial and cytosolic ALDHs.
authors: Department of Zoology & Genetics, Iowa State University, Ames 50011, USA.
authors: David S
authors: DS
authors: Skibbe
authors: Feng
authors: F
authors: Liu
authors: Tsui-Jung
authors: TJ
authors: Wen
authors: Marna D
authors: MD
authors: Yandeau
authors: Xiangqin
authors: X
authors: Cui
authors: Jun
authors: J
authors: Cao
authors: Carl R
authors: CR
authors: Simmons
authors: Patrick S
authors: PS
authors: Schnable
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005091:Exons; D005796:Genes / Q000235:genetics; D005816:Genetic Complementation Test; D007438:Introns; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010802:Phylogeny; D013045:Species Specificity; D003313:Zea mays / Q000201:enzymology / Q000235:genetics*
chemical_list: D007527:Isoenzymes; D000444:Aldehyde Dehydrogenase