GSN1 coordinates grain number and grain size (Plant Cell)

Grain yield is determined by both grain number and grain weight. There is often a trade-off between these traits; for example, increased grain number is often associated with decreased grain weight. Using a forward-genetic approach, Guo et al. have identified a rice gene, GRAIN SIZE AND NUMBER1 (GSN1) that affects these traits. GSN1 encodes a mitogen-activated protein kinase phosphatase. Increasing GSN1 activity leads to more, smaller grains, and decreasing it leads to fewer, larger grains. GSN1 acts by affecting the rate of cell proliferation and interacts with the MAP kinase signaling cascade. (Summary by Mary Williams) Plant Cell 10.1105/tpc.17.00959