Maternally Produced siRNAs Regulate Seed Size

Scientists at the University of Texas discovered that seed size is controlled by small RNA molecules inherited from a plant's mother. This discovery has implications for agriculture and in understanding evolution of plants.

In their paper published in the April 3 issue of PNAS, scientist Jeffrey Chen and colleagues provided the first genetic evidence that small interfering RNAs (siRNAs) affect the development of endosperm, which is the source of nutrition of developing plant embryo. Their findings showed that when a female plant with a duplicate genome is crossed with a male plant with a normal genome, the maternal genome increased in the offspring's seed endosperm and the maternal siRNAs also increased. The increase in maternal siRNAs causes the reduction in gene expression that lead to larger endosperm growth, meaning that the siRNAs leads to production of smaller seeds.

These findings will guide the scientists in developing biotech tools to enhance seed production and crop yield.

Read the media release at http://www.utexas.edu/news/2012/04/11/seed_size_chen/ and the research article at http://www.pnas.org/content/109/14/5529.full?sid=5d9545e9-4719-453b-8722-916690b39872.