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ABSTRACT: The inheritance of flower color in pea (Pisum sativum) has been studied for more than a century, but many of the genes corresponding to these classical loci remain unidentified. Anthocyanins are the main flower pigments in pea. These are generated via the flavonoid biosynthetic pathway, which has been studied in detail and is well conserved among higher plants. A previous proposal that the Clariroseus (B) gene of pea controls hydroxylation at the 5' position of the B ring of flavonoid precursors of the anthocyanins suggested to us that the gene encoding flavonoid 3',5'-hydroxylase (F3'5'H), the enzyme that hydroxylates the 5' position of the B ring, was a good candidate for B. In order to test this hypothesis, we examined mutants generated by fast neutron bombardment. We found allelic pink-flowered b mutant lines that carried a variety of lesions in an F3'5'H gene, including complete gene deletions. The b mutants lacked glycosylated delphinidin and petunidin, the major pigments present in the progenitor purple-flowered wild-type pea. These results, combined with the finding that the F3'5'H gene cosegregates with b in a genetic mapping population, strongly support our hypothesis that the B gene of pea corresponds to a F3'5'H gene. The molecular characterization of genes involved in pigmentation in pea provides valuable anchor markers for comparative legume genomics and will help to identify differences in anthocyanin biosynthesis that lead to variation in pigmentation among legume species.
Plant physiology 04/2012; 159(2):759-68. · 6.53 Impact Factor
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ABSTRACT: Mendel's paper 'Versuche über Pflanzen-Hybriden' is the best known in a series of studies published in the late 18th and 19th centuries that built our understanding of the mechanism of inheritance. Mendel investigated the segregation of seven gene characters of pea (Pisum sativum), of which four have been identified. Here, we review what is known about the molecular nature of these genes, which encode enzymes (R and Le), a biochemical regulator (I) and a transcription factor (A). The mutations are: a transposon insertion (r), an amino acid insertion (i), a splice variant (a) and a missense mutation (le-1). The nature of the three remaining uncharacterized characters (green versus yellow pods, inflated versus constricted pods, and axial versus terminal flowers) is discussed.
Trends in Plant Science 07/2011; 16(11):590-6. · 11.05 Impact Factor
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Roger P Hellens,
Carol Moreau,
Kui Lin-Wang,
Kathy E Schwinn,
Susan J Thomson,
Mark W E J Fiers,
Tonya J Frew,
Sarah R Murray, Julie M I Hofer,
Jeanne M E Jacobs,
Kevin M Davies,
Andrew C Allan,
Abdelhafid Bendahmane,
Clarice J Coyne,
Gail M Timmerman-Vaughan,
T H Noel Ellis
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ABSTRACT: The genetic regulation of flower color has been widely studied, notably as a character used by Mendel and his predecessors in the study of inheritance in pea.
We used the genome sequence of model legumes, together with their known synteny to the pea genome to identify candidate genes for the A and A2 loci in pea. We then used a combination of genetic mapping, fast neutron mutant analysis, allelic diversity, transcript quantification and transient expression complementation studies to confirm the identity of the candidates.
We have identified the pea genes A and A2. A is the factor determining anthocyanin pigmentation in pea that was used by Gregor Mendel 150 years ago in his study of inheritance. The A gene encodes a bHLH transcription factor. The white flowered mutant allele most likely used by Mendel is a simple G to A transition in a splice donor site that leads to a mis-spliced mRNA with a premature stop codon, and we have identified a second rare mutant allele. The A2 gene encodes a WD40 protein that is part of an evolutionarily conserved regulatory complex.
PLoS ONE 01/2010; 5(10):e13230. · 4.09 Impact Factor
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Michael K Udvardi,
Klementina Kakar,
Maren Wandrey,
Ombretta Montanari,
Jeremy Murray,
Andry Andriankaja,
Ji-Yi Zhang,
Vagner Benedito, Julie M I Hofer,
Foo Chueng,
Christopher D Town
Plant physiology 07/2007; 144(2):538-49. · 6.53 Impact Factor
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ABSTRACT: Pinnate compound leaves have laminae called leaflets distributed at intervals along an axis, the rachis, whereas simple leaves have a single lamina. In simple- and compound-leaved species, the PHANTASTICA (PHAN) gene is required for lamina formation. Antirrhinum majus mutants lacking a functional gene develop abaxialized, bladeless adult leaves. Transgenic downregulation of PHAN in the compound tomato (Solanum lycopersicum) leaf results in an abaxialized rachis without leaflets. The extent of PHAN gene expression was found to be correlated with leaf morphology in diverse compound-leaved species; pinnate leaves had a complete adaxial domain of PHAN gene expression, and peltate leaves had a diminished domain. These previous studies predict the form of a compound-leaved phan mutant to be either peltate or an abaxialized rachis. Here, we characterize crispa, a phan mutant in pea (Pisum sativum), and find that the compound leaf remains pinnate, with individual leaflets abaxialized, rather than the whole leaf. The mutant develops ectopic stipules on the petiole-rachis axis, which are associated with ectopic class 1 KNOTTED1-like homeobox (KNOX) gene expression, showing that the interaction between CRISPA and the KNOX gene PISUM SATIVUM KNOTTED2 specifies stipule boundaries. KNOX and CRISPA gene expression patterns indicate that the mechanism of pea leaf initiation is more like Arabidopsis thaliana than tomato.
The Plant Cell 05/2005; 17(4):1046-60. · 8.99 Impact Factor
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Plant physiology 04/2003; 131(3):927-34. · 6.53 Impact Factor
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ABSTRACT: SQUAMOSA and APETALA1 are floral meristem identity genes from snapdragon (Antirrhinum majus) and Arabidopsis, respectively. Here, we characterize the floral meristem identity mutation proliferating inflorescence meristem (pim) from pea (Pisum sativum) and show that it corresponds to a defect in the PEAM4 gene, a homolog of SQUAMOSA and APETALA1. The PEAM4 coding region was deleted in the pim-1 allele, and this deletion cosegregated with the pim-1 mutant phenotype. The pim-2 allele carried a nucleotide substitution at a predicted 5' splice site that resulted in mis-splicing of pim-2 mRNA. PCR products corresponding to unspliced and exon-skipped mRNA species were observed. The pim-1 and pim-2 mutations delayed floral meristem specification and altered floral morphology significantly but had no observable effect on vegetative development. These floral-specific mutant phenotypes and the restriction of PIM gene expression to flowers contrast with other known floral meristem genes in pea that additionally affect vegetative development. The identification of PIM provides an opportunity to compare pathways to flowering in species with different inflorescence architectures.
Plant physiology 08/2002; 129(3):1150-9. · 6.53 Impact Factor
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ABSTRACT: The C2H2 TFIIIA/Krppel class of zinc finger proteins are an important group of regulatory nucleic acid binding factors and have been extensively studied in humans, Drosophila and yeast. We have employed 3 RACE PCR, using a highly degenerate oligonucleotide primer, for the facile isolation of a C2H2 zinc finger protein cDNA (Pszf1) from pea petals. The Pszf1 cDNA open reading frame potentially encodes a protein with two widely separated zinc fingers similar to zinc finger proteins from petunia and wheat. This class of two-fingered zinc finger proteins, possessing a wide and variable linker sequence, appears to be unique to plants. Three regions outside the zinc finger domains are also conserved between the members of the plant zinc finger protein family and one of these regions is a candidate nuclear localisation signal. The Pszf1 amino acid sequence is most similar to that of the petunia Epf1 protein, they possess an interfinger linker sequence of approximately the same length and they have a similar expression pattern with maximal transcript accumulation in mature petals, suggesting that Pszf1 may be the pea homologue of the petunia Epf1 zinc finger gene.
Plant Molecular Biology 02/1996; 30(5):1051-1058. · 4.15 Impact Factor
