The Donald Danforth Plant Science Center marked the official start of a $45 million expansion with a groundbreaking ceremony in St. Louis County. The 79,000-square-foot facility will house research labs for robotics and bioinformatics. It will include space for 10 new scientific teams and at least 100 new employees, officials said. Construction is expected to be completed in late 2015. The project, a three-story addition to the center’s existing research building, is receiving $4.5 million in Contribution Tax Credits from the Missouri Development Finance Board.