Is posible although not practical in the glass aquarium, when common plecs breed they dig a 4-5deep hole in a mud bank and raise their eggs in it, common plecs are mass bred in countrys with warmer climates in muddy ponds, which is partly why they are so cheap.
Personally im thankful that common plecs cant be bred in the average aquarium as there are too many around for their own good needing homes anyways in my honest opinion.