Sugar Transportation and Seed Size (IMAGE) Carnegie Institution for Science Caption Sugars are manufactured in the leaves, when the plant turns the Sun's energy into chemical energy, and then transported to the seeds. The amount of sugars that fill a seed directly determines the seed's size. The ancestors of the modern maize planted today in the US and worldwide had much smaller endosperms. It is thought that seed sizes were increased by the selective pressures of agricultural domestication. Larger, more sugar-filled seeds such as maize kernels were more attractive to human cultivators, due to their nutritive value and their ability to produce sturdier seedlings. Images provided courtesy of Davide Sosso, lead author of this study. Credit Davide Sosso Usage Restrictions With credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.