Mendel’s remaining three pea traits solved by massive pea genome study

Amazing stuff! Like the fairy tale "The Princess and the Pea" Just kidding!

"... how the 19th century Austro-Hungarian friar Gregor Mendel discovered the basic principles of genetics by studying peas, which he planted by the thousands in the garden of his abbey. ... the molecular basis of his seven traits.

In recent decades, researchers have identified the genes behind four of them.

Now, in the largest genomic study of peas yet, a team reveals the genes associated with the remaining three traits, as well as many other genes that pea breeders could use to improve the plants.

For the new work, the team sequenced nearly 700 pea varieties. This yielded 155 million molecular markers that they correlated with physical traits of the plants, allowing them to narrow down the location of important genes.

Among those genes are ones for the three remaining Mendel traits:

the color of the pea pod, the arrangement of flowers, and whether the pods are edible.

The new details show, for example, that yellow pods occur in plants with DNA missing next to a gene involved in making chlorophyll. That particular insight might not lead directly to improved peas, but others likely will. Many other traits in peas are determined by multiple genes, and there, too, genomic maps with plentiful markers will help breeders build on the heritage of Mendel. ..."

"... The entire pea genome was sequenced in 2019. Researchers in China went on to sequence 237 kinds of peas and compile their genetic differences into a map, published last year. This diversity allowed them to identify 29 million genetic markers, called single nucleotide polymorphisms (SNPs), that pea breeders can use to guide and accelerate crop improvement. ..."

From the abstract:

"Mendel studied in detail seven pairs of contrasting traits in pea (Pisum sativum), establishing the foundational principles of genetic inheritance.

Here we investigate the genetic architecture that underlies these traits and uncover previously undescribed alleles for the four characterized Mendelian genes, including a rare revertant of Mendel’s white-flowered a allele.

Primarily, we focus on the three remaining uncharacterized traits and find that
(1) an approximately 100-kb genomic deletion upstream of the Chlorophyll synthase (ChlG) gene disrupts chlorophyll biosynthesis through the generation of intergenic transcriptional fusion products, conferring the yellow pod phenotype of gp mutants;
(2) a MYB gene with an upstream Ogre element insertion and a CLE peptide-encoding gene with an in-frame premature stop codon explain the v and p alleles, which disrupt secondary cell wall thickening and lignification, resulting in the parchmentless, edible-pod phenotype; and
(3) a 5-bp exonic deletion in a CIK-like co-receptor kinase gene, in combination with a genetic modifier locus, is associated with the fasciated stem (fa) phenotype.

Furthermore, we characterize genes and alleles associated with diverse agronomic traits, such as axil ring anthocyanin pigmentation, seed size and the ‘semi-leafless’ form. This study establishes a foundation for fundamental research, education in biology and genetics, and pea breeding practices."

ScienceAdviser

Massive pea study solves last genetic riddles of famed friar "DNA sequencing reveals basis of traits studied by Gregor Mendel—and gives breeders new ways to improve the crop"

Genomic and genetic insights into Mendel’s pea genes (open access)

Yellow pods were a clue that helped Gregor Mendel figure out patterns of heredity.