To meet the requirements of the retirement system for the period between the time when sections 169.010 to 169.130 shall take effect and the time when sufficient contributions to the system are transmitted by employers, the board of trustees shall have authority to accept on behalf of the system such grants or appropriations as may be made to them or it by the general assembly of Missouri and to repay and return the same to the state treasury when funds of the system sufficient therefor are available; provided, that any funds appropriated by the general assembly shall be repaid within two years after the effective date of sections 169.010 to 169.130; and provided further, that the state of Missouri shall contribute no funds directly or indirectly to finance the plan to pay retirement allowances by appropriation bills or otherwise, except for payments or contributions of persons employed by the state board of education as provided in subsection 6 of section 169.010, and except those funds which the district may receive from time to time under a law or laws providing for a general apportionment of school moneys throughout all the state.