  Let $\mathcal{L}=-\Delta+V$ be a Schr\"{o}dinger operator, where the
nonnegative potential $V$ belongs to the reverse H\"{o}lder class $B_{q}$. By
the aid of the subordinative formula, we estimate the regularities of the
fractional heat semigroup, $\{e^{-t\mathcal{L}^{\alpha}}\}_{t>0},$ associated
with $\mathcal{L}$. As an application, we obtain the
$BMO^{\gamma}_{\mathcal{L}}$-boundedness of the maximal function, and the
Littlewood-Paley $g$-functions associated with $\mathcal{L}$ via $T1$ theorem,
respectively.
