The rights and remedies conferred by this part upon or granted to bondholders are in addition to and not in limitation of any rights and remedies lawfully granted to such bondholders by the resolutions providing for the issuance of bonds, or by any deed of trust, indenture, or other agreement under which the bonds are issued.
If the board defaults in the payment of principal or interest on any of the bonds after the principal or interest becomes due, whether at maturity or upon call for redemption, and if such default continues for a period of 60 days, or if the board fails or refuses to comply with the provisions of this part or
defaults in any agreement made with the bondholders, the holders of 25 percent in aggregate principal amount of the bonds then outstanding by instruments filed in the Office of the County Recorder of the County of Sacramento, and acknowledged in the same manner as a deed to be recorded except as this right is limited under the provisions of any deed of trust, indenture, or other agreement, may appoint a trustee to represent the bondholders for the purposes provided in this part. The trustee or any trustee under any deed of trust, indenture, or other agreement may, and upon written request of the holders of 25 percent in principal amount of the bonds then outstanding, or such other percentage as is specified in the deed of trust, indenture or other agreement, shall in his name: