Corn Genetics Research Exposes Mechanism Behind Traits Becoming Silent

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For more than a century, plant geneticists have been studying maize as a model system to understand the rules governing the inheritance of traits, and a team of researchers recently unveiled a previously unknown mechanism that triggers gene silencing in corn.

For more than a century, plant geneticists have been studying maize as a model system to understand the rules governing the inheritance of traits, and a team of researchers recently unveiled a previously unknown mechanism that triggers gene silencing in corn.

Gene silencing turns off genetic traits, an important consideration for plant breeders who depend on the faithful inheritance of traits from one generation to the next.

Historically, the maize p1 gene has been used as a model by maize geneticists. Previous researchers did not know that two types of overlapping DNA methylation marks could modify, silence or activate this gene. The discovery adds to geneticists' knowledge of different mechanisms of non-Mendelian inheritance, according to lead researcher Surinder Chopra, professor of maize genetics, College of Agricultural Sciences, Penn State.

In findings reported in PLOS One, Chopra's team showed that silencing the corn pericarp color 1 gene — regulator of the kernels' outer layer color and the cob color — can have two "overlapping" epigenetic components — RNA dependent DNA methylation (RdDM) and non-RNA dependent DNA methylation (non-RdDM).

Read more at Penn State

Image: Diverse maize cobs showing the varying genetic traits of kernel and cob colors (Credit: Surinder Chopra, Penn State)