Identification of Mendel's white flower character - PubMed (original) (raw)

Figure 2. Molecular characterization of the a mutation in white flowered pea cultivars.

(A) Schematic diagram showing the main features of the bHLH gene and its expression products (not to scale). In Caméor, a white flowered pea cultivar of genotype a, there is a single G to A mutation at the intron 6 splice donor site that disrupts the GT sequence required for normal intron processing. In the DNA, exons 6 and 7 are shown as grey boxes that flank the intron 6 splice donor and acceptor sequences. In the RNA, the vertical lines represent exon junctions and the light grey box represents the 8 nucleotide (nt) insertion in the a mRNA that results from mis-splicing of intron 6. The red stars show the position of the stop codon in the predicted protein, highlighting the premature termination in the white flowered cultivar. (B) Quantitative RT-PCR of bHLH in petal RNA from pigmented and white flowered Plant Inventory (PI) lines, 1; PI 174320, 2; PI 343331, 3; PI 343958, 4; PI 195404, 5; PI 279825, 6; PI 411143, 7; PI 174921, 8; PI 166159, 9; PI 116844, 10; PI 272204, 11; PI 155109, 12; PI 169603, 13; JI 2822, 14; Caméor. Transcript abundance relative to EF1α from pea was calculated according to the method of Pfaffl . Individual experimental replications are shown. To the right of the figure the average for A and a alleles is shown with error bars showing one standard deviation (A: µ = 26.8, SD = 18.0, n = 8; a: µ = 7.5, SD = 4.7, n = 6). (C) Flowers from the twelve PI lines, JI 2822 and Caméor used in this analysis. (D) RT-PCR products spanning the exon6-exon7 junction. The molecular weight standard is shown in the far left. All eight colored flowered peas show a 79 bp amplification product and all white flowered peas show a larger, 87 bp product.