Erro ao conectar ao banco de dados!

PDOException: SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: NO) in /home2/tvloja79/aprendizbrasil.com/sistema/conexao.php:8 Stack trace: #0 /home2/tvloja79/aprendizbrasil.com/sistema/conexao.php(8): PDO->__construct('mysql:dbname=po...', 'root', Object(SensitiveParameterValue)) #1 /home2/tvloja79/aprendizbrasil.com/cabecalho.php(2): require_once('/home2/tvloja79...') #2 /home2/tvloja79/aprendizbrasil.com/index.php(2): require_once('/home2/tvloja79...') #3 {main}