During the period of the first twelve (12) months after appointment, any member of the Mississippi Highway Safety Patrol shall be subject to dismissal at the will of the commissioner. After twelve (12) months' service, no member of the patrol shall be subject to dismissal or otherwise have his salary adversely affected except for cause, and any such action against an officer of the Mississippi Highway Safety Patrol shall be subject to and proceed under the laws, rules and regulations of the state personnel system.