Through the grapevine: Molecular mechanisms behind Pinot berry color variation

Variations in the color of grapevine berries within the Pinot family result from naturally-occurring genetic mutations that selectively shut down the genes responsible for the synthesis of red pigments, called anthocyanins. This has led to the emergence of Pinot blanc and Pinot gris from Pinot noir. Frédérique Pelsy and her colleagues, from the "Grapevine Health and Wine Quality" research unit at INRA Colmar, France, published these findings in PLOS Genetics on 2 April 2015.

The vine stocks used in viticulture are obtained by grafting; therefore, for any given variety, all stocks are identical...or almost all. Spontaneous events in the genomes of some vines lead to differences between individual plants. In this study, the researchers reveal the molecular mechanisms that underpin the change of berry color in greater detail. This was done by studying a collection of 33 clones of Pinot noir, Pinot gris and Pinot blanc. For the first time, they have shown that large-scale exchanges between homologous chromosomes, sometimes associated with deletions, selectively shut down the genes that induce the biosynthesis of anthocyanins. These somatic mutations, which occur in a cell, propagate to form a distinct cell layer, leading to chimeric plants. This is how chimeric Pinot gris arises from Pinot noir: a Pinot noir skin surrounds internal cells that have mutated to Pinot blanc. Subsequently, Pinot blanc can emerge from Pinot gris as a result of cellular rearrangements that spread the mutations throughout the plant.

In this study, berry color was used as a model trait to shed light on the driving forces behind the genetic drift of clones and the evolution of the grapevine genome. Similar molecular and cellular mechanisms may impact other vegetatively propagated plants, creating clonal diversity.

###

FINANCIAL DISCLOSURE: SH was a doctoral fellow funded by the Conseil Régional d'Alsace. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

COMPETING INTERESTS: The authors have declared that no competing interests exist.

CITATION: Pelsy F, Dumas V, Bévilacqua L, Hocquigny S, Merdinoglu D (2015) Chromosome Replacement and Deletion Lead to Clonal Polymorphism of Berry Color in Grapevine. PLoS Genet 11(4): e1005081. doi:10.1371/journal.pgen.1005081

PLEASE ADD THIS LINK TO THE FREELY AVAILABLE ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (the link will go live when the embargo ends): http://www.plosgenetics.org/doi/pgen.1005081

CONTACTS: Frédérique Pelsy (frederique.pelsy@colmar.inra.fr)

This press release refers to an upcoming article in PLOS Genetics. The release is provided by journal staff, or by the article authors and/or their institutions. Any opinions expressed in this release or article are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLOS. PLOS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.

PLOS Genetics reflects the full breadth and interdisciplinary nature of genetics and genomics research by publishing outstanding original contributions in all areas of biology. All works published in PLOS Genetics are open access. Everything is immediately and freely available online throughout the world subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

The Public Library of Science (PLOS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.