Missouri Revised Statutes Title XXIII. Corporations, Associations and Partnerships § 351.093. Certain shareholders must be permitted to vote, when

1. The holders of the outstanding shares of a class shall be entitled to vote as a class upon a proposed amendment to the articles of incorporation, whether or not entitled to vote thereon by the provisions of such articles if the amendment would increase or decrease the aggregate number of authorized shares of such class; increase or decrease the par value of the shares of such class; create a new class of shares having rights and preferences prior or superior to the shares of the class, or increase the rights and preferences or the number of authorized shares, of any class having rights and preferences prior or superior to the shares of the class; or alter or change the powers, preferences, or special rights of the shares of such class so as to affect them adversely. A merger or consolidation shall not be deemed to involve a proposed amendment to the articles of incorporation.

2. If any proposed amendment would alter or change the powers, preferences, or special rights of one or more series of any class, so as to affect them adversely, but would not so affect the entire class, then only the shares of the series so affected by the amendment shall be considered a separate class for the purpose of this section.