The study appears online in the journal The Plant Cell.
Plant breeders tend to expect to generate desired traits according to what is known as Mendelian principles of inheritance: Offspring receive one copy of genes from each parental plant, and the characteristics of the alleles, or alternative forms of genes, help predict which traits will show up in the next plant generation.
However, epigenetic variations that change the predictability of gene behavior have complicated those expectations.
"The breeding community searches for novel traits that will have commercial interest and they really don't care what the basis is as long as they can capture it and breed it. Epigenetic heritability throws a kink in the expectations, but our findings also provide an opportunity if they recognize the variation they're looking for is the result of epigenetics, they could use that to their advantage," said Hollick, also an investigator in Ohio State's centers for RNA Biology and Applied Plant Sciences.
"Just by knowing that this allele behaves in this epigenetic fashion, I can breed plants that either have full coloration or no coloration or anything in between, because I am manipulating epigenetic variation and not genetic variation. And color, of course, is only one trait that could be affected."
With a longtime specialization in the molecular basis for unexpected gene activity in plants, Hollick had zeroed in on an enzyme called RNA polymerase IV (Pol IV). Multiple types of RNA polymerases are responsible for setting gene expression in motion in all cells, and Pol IV is an enigmatic RNA polymerase that is known in plants to produce small RNA molecules.
Pol IV has puzzled scientists because despite its strong conservation in all plants, it appears to have no discernible impact on the development of Arabidopsis, a common model organism in plant biology. For example, when it is deleted from these plants, they sho
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Ohio State University