It depends what you want to see. The root meristem is full of dividing cells. So you can use DAPI to stain nuclei and/or propidium iodide to stain the cell wall. Then, you can use normal fluorescence or confocal microscopy to identify the dividing cells.

Thanks so much. I thought DAPI is better.

I think, H&E staining is better for evaluating dividing cells

Yeah, maybe. In our field, Haematoxylin was used to detect early cell divisions previously. I have search for that staining method, but unfortunately, they all refered to "Dudley et al., 1987" and i could not get the paper.