A Chicago biotech start-up scored its first major deal Tuesday when Monsanto Co. agreed to a research partnership to genetically engineer crops like corn or soybeans more quickly than by using standard technology. [...] Chromatin’s technology was developed by Daphne Preuss, a University of Chicago biology professor, in research with weeds. Preuss, who is on leave from the U. of C., is president and chief scientific officer at Chromatin. [...] ”This is a significant milestone for a technology that has come a long way since its development at the university,” said Alan Thomas, director of intellectual property at the University of Chicago. ”We hope this is the first of many such announcements.”