Ask yourself why it was pVg$pVg$ in case of non accelerated (inertial) frame. Because the pressure gradient is pg$pg$ or p$p$ times the acceleration due to the force that is pulling it downwards.
Now in an accelerated frame, the pressure gradient is not really pg$pg$ but p(g+a)$p(g+a)$.
If you had to write pressure at a depth d$d$, would you write pVg$pVg$ or pV (g+a)$pV (g+a)$?