sentences:  He served as a postdoctoral fellow from 1980 through 1981 on a joint project between Washington University, Stanford University and the University of California, Berkeley.From 1981 to 1983 he was a research scientist at the International Plant Research Institute.In 1983, Bennetzen became an Assistant Professor at Purdue University, becoming a full Professor in 1991 and H. Edwin Umbarger Distinguished Professor of Genetics in 1999.