There shall be chosen by the qualified electors of the state at the times and places of choosing members of the legislative assembly, a secretary of state, auditor, treasurer, superintendent of public instruction, commissioner of insurance, an attorney general, a commissioner of agriculture and labor, and a tax commissioner, who shall have attained the age of twenty-five years and shall have the qualifications of state electors. They shall severally hold their offices at the seat of government for the term of four years beginning with the year 1965, and until their successors are elected and duly qualified; but no person shall be eligible for the office of treasurer for more than two consecutive terms.

The board of railroad commissioners shall hereafter be known as the public service commission and the members of the board of railroad commissioners as public service commissioners and the powers and duties now or hereafter granted to and conferred upon the board of railroad commissioners are hereby transferred to the public service commission.

The public service commissioners shall have the qualifications of state electors, have attained the age of twenty-five years, be chosen by the qualified electors of the state at the times and places of choosing members of the legislative assembly, hold office at the seat of government and until their successors are elected and duly qualified. As each of the three public service commissioners now holding office completes his term, his successor shall be elected for a term of six years.

The legislative assembly may by law provide for a department of labor, which, if provided for, shall be separate and distinct from the department of agriculture, and shall be administered by a public official who may be either elected or appointed, whichever the legislative assembly shall declare; and if such a department is established the commissioner of agriculture and labor provided for above shall become the commissioner of agriculture.