|Wang, Kui Lin|
|Schwinn, Kathy E|
|Coyne, Clarice - Clare|
Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2010
Publication Date: 10/11/2010
Citation: Hellens, R.P., Moreau, C., Wang, K., Schwinn, K., Thomson, S., Fiers, M., Frew, T.J., Murray, S.R., Hofer, J., Jacobs, J., Davies, K.M., Allan, A.C., Bendahmane, A., Coyne, C.J., Timmerman, G.M., Ellis, N.T. 2010. Identification of Mendel's white flower character. PLoS One. 5 (10). Interpretive Summary: The segregation of flower color in the progeny of pea crosses is well known in genetics because of Mendel’s experiments. The timing of Mendel’s experiments suggests that it was in the spring of 1860 that Mendel counted the segregation ratios for this pigmentation character, immortalized in his famous ratio of 1AA:2Aa:1aa later became the symbol for the gene that determines the accumulation of anthocyanin pigmentation throughout the plant, most notably in flowers. White flowered cultivated forms of pea are common and were available to Mendel, but wild peas have purple flowers, as presumably did the earliest cultivated forms. This raises the question of when white flowered types arose. White flowered forms have been in existence for at least 600 years, but the precise date of their origin remains unknown. The purple color that accumulates in wild type peas is due to anthocyanin pigments; compounds derived from phenylalanine. Pea has not been the subject of a genome sequencing project, but its genome is known to be extensively collinear with that of Medicago truncatula and we investigated whether any regions of the M. truncatula genome containing candidate genes were syntenic with the A locus in pea. This analysis eliminated all but one bHLH gene.
Technical Abstract: We have identified A, 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.