The entire opposition, including the Telugu Desam Party, Telangana Rashtriya Samiti, Bharatiya Janata Party, Communist Party of India and CPI-Marxixt, had earlier announced that it would back the shutdown called by the Andhra Pradesh Backward Classes Welfare Association.
Expressing solidarity with the strike, the government asked the Road Transport Corporation to suspend its bus services.
All public examinations scheduled for Wednesday would be postponed to a later date, Backward Classes Welfare Minister D Srinivas told reporters here.
"We are in total agreement with the demand that the Centre should take necessary measures for implementing the reservation for OBCs," he said. State Congress president K Kesava Rao said the shutdown was a "democratic expression" and appealed to people to make it a success.
"It is heartening that all parties are supporting the bandh. I hope it will be an eye-opener to those who oppose reservations for backward classes," he said.
Apart from participating in the shutdown, the main opposition TDP will hold dharnas in the headquarters of all districts on April 11.
Telangana Rashtra Samithi chief and member of Parliament K Chandrasekhar Rao will take part in a rail roko programme in Secunderabad as part of the shutdown.