Polysome Formation in Light-sensitive Common Purslane Seeds

Common purslane (Portulaca oleracea L.) seeds show light-controlled dormancy. Ribosome profiles from dark-incubated seeds consist of 22 to 26% polysomes. Light induces germination and stimulates polysome formation during the 12-hour lag period preceding radicle protrusion. Polysome levels increase to 29, 35, and 41% with exposure to 3, 6, and 9 hours of light, respectively. Although polysomes form on imbibition in the dark, 6 hours of light stimulates a significant increase in polysome formation which is probably related to early stages of radicle elongation.