The state pledges and agrees with the holders of any bonds or notes issued under this article that the state will not limit or alter the rights vested in the board to fulfill the terms of any agreements made with the holders thereof, or in any way impair the rights and remedies of the holders, until the bonds or notes, together with the interest thereon, and all costs and expenses in connection with any action or proceeding by or on behalf of such holders, are fully met and discharged. The board is authorized to include his pledge and agreement of the state in any agreement with the holders of such bonds or notes.