“It was basically mentioned in every conversation,” said Nathan Kurtz, who heads entrepreneurship programs for the Kansas City-based Ewing Marion Kauffman Foundation and was in town for the conference.

How the deal might ultimately affect the region’s plant science industry is unclear. Much depends on how much Bayer’s top decision-makers in Germany decide to invest in St. Louis area operations, which will include the seeds and traits headquarters for Bayer’s crop science division.

Bayer officials emphasized that it’s in their interest to keep scientific talent in the region and to help startups grow through grants, venture funds and other outreach.

“We will want to further strengthen this going forward because the core for everything biotech, seeds and traits is going to be St. Louis,” Liam Condon, the head of Bayer’s crop science division, told the Post-Dispatch. “The ecosystem you require to thrive can never just be internal. It has to be a supporting community.”

A deal is far from certain. Antitrust regulators are expected to scrutinize the transaction closely. Monsanto’s stock, already trading well below Bayer’s offer price of $128 per share on fears that regulators will block the deal, fell 2 percent Thursday to $104.22.