Governor E S L Narasimhan administered the oath of office to the ruling YSR Congress MLA from Bobbili in Vizianagaram district, at a brief function in the state Secretariat.
Chief Minister Y S Jagan Mohan Reddy and other YSRC leaders were present.
Appalanaidu has been elected to the Assembly for the fourth time.
As pro-tem Speaker, Appalanaidu will preside over the swearing-in of newly-elected MLAs on June 12 and 13.
He will also conduct the election for the Speaker's post on June 13 before completing his constitutional obligation.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)