In order for a plant cell to elongate, what two things must occur

A plant cell consists of a cell wall, chloroplast and vacuoles that makes it different from the animal cell.
For a plant cell to elongate, two things that facilitates the process are light and phytohormones. It occurs when individual cells and group of cells grow longer.
In order for a plant cell to elongate, two things that must occur are:
1. temporary loosening of cell wall
2. pumping hydrogen ions across the cell membrane.

It's cell theory. easy name i would think.