The bonds may be secured by an indenture by and between the company and a corporate trustee which may be any bank or other corporation having the power of a trust company or any trust company within or without this state. Such indenture may contain such provisions for protecting and enforcing the rights and remedies of the bondholders as may be reasonable and proper and not in violation of law, including covenants setting forth the duties of the company in relation to the exercise of its powers and the custody, safekeeping and application of all money. The company may provide by the indenture for the payment of the proceeds of the bonds and revenues to the trustee under the indenture or other depository, and for the method of disbursement thereof, with such safeguards and restrictions as the company may determine. If the bonds shall be secured by an indenture, the bondholders shall have no authority to appoint a separate trustee to represent them.