Emacs is said to do The Right Thing, but it looks like that is not the case for Perl. It defaults to perl-mode, which can be hopefully replaced by cperl-mode, with some additional lines in the ~/.emacs configuration file.

;;  We always prefer CPerl mode to Perl mode.
(fset 'perl-mode 'cperl-mode)

;;  When starting load my hooks
(add-hook 'cperl-mode-hook 'my-cperl-mode-hook t)

;;  Ensure we use PerlStyle
(defun my-cperl-mode-hook ()
  (cperl-set-style "PerlStyle")