ST. LOUIS and ROMAINVILLE, France, Sept. 1, 2009 — Monsanto Company (NYSE: MON) today announced a non-exclusive research and commercial license agreement with France-based Cellectis S.A. (Alternext: ALCLS), a biotechnology company specialized in genome engineering, for broad use of its meganuclease technology in plants.

Meganucleases are molecular scissors that can be directed to a single site in the genome of a plant cell, thereby allowing a wide range of precise genome modifications, including gene stacking, gene knock-out as well as modulation of gene function to develop new traits. Under the agreement, Monsanto will have access to Cellectis’ intellectual property on meganucleases and its custom meganuclease production platform.

Cellectis will receive an upfront payment of euro 3 million, and subject to the approval of the Extraordinary General Meeting of Cellectis’ shareholders, Monsanto will make an equity investment of euro 1 million to allow Cellectis to scale the technology for agriculture. Cellectis will also be eligible to receive fees for the development of each meganuclease, success-based milestones and may receive royalties on certain traits commercialized by Monsanto. Further financial details of the agreement were not disclosed.

“Being able to make precise genome modifications could enable us to advance projects even more rapidly through our R&D pipeline,” said Robert Fraley, chief technology officer for Monsanto. “This technology has the potential to accelerate delivery of our ever expanding trait pipeline to farmers in the form of value-added, multi-trait products.”

“This agreement with Monsanto, the leader in agricultural biotechnology, could allow our meganuclease-based genome engineering technology to be put to use in developing the next generation of quality crops,” said Andre Choulika, chief executive officer of Cellectis. “The number of meganuclease users in agricultural biotechnology continues to grow. This agreement confirms our leading position in targeted gene modifications.”

About Monsanto Company

Monsanto Company is a leading global provider of technology-based solutions and agricultural products that improve farm productivity and food quality. Monsanto remains focused on enabling both small-holder and large-scale farmers to produce more from their land while conserving more of our world’s natural resources such as water and energy. To learn more about our business and our commitments, please visit: www.monsanto.com.

About Cellectis

Cellectis S.A. is a world leader in genome engineering and genome surgery. For more information on Cellectis, visit our website www.cellectis.com.

Cautionary Statements Regarding Forward-Looking Information:

Certain statements contained in this press release are forward-looking statements, such as statements concerning the company’s future product performance, regulatory approvals, business and financial plans and other non-historical facts. These statements are based on current expectations and currently available information. However, since these statements are based on factors that involve risks and uncertainties, the company’s actual performance and results may differ materially from those described or implied by such forward-looking statements. Factors that could cause or contribute to such differences include, among others: the success of the companies’ research and development activities; the costs of and the companies’ abilities to access and enforce intellectual property needed for the collaboration; the costs and requirements of regulatory compliance and the speed with which approvals are received; public acceptance of biotechnology products; and other risks and factors detailed in the company’s most recent periodic report to the SEC. Undue reliance should not be placed on these forward-looking statements, which are current only as of the date of this presentation. The company disclaims any current intention or obligation to update any forward-looking statements or any of the factors that may affect actual results.