All commissioned and warrant officers of the South Carolina National Guard shall be appointed and commissioned or warranted by the Governor. No person shall be appointed and commissioned or warranted unless he shall be a citizen of the United States and a resident of this State. His age shall conform to the age requirements as set forth in the regulations issued by the National Guard Bureau and that are in effect at the time of appointment. Every commissioned or warrant officer shall hold office under his commission or warrant until he shall have been regularly appointed and commissioned or warranted to another grade or office or until he shall have been regularly retired, discharged, dismissed or placed in an inactive status.