Do leaves grow larger by adding cells at the centre or at the edge?

Question

I'm writing a paper on wrinkling of plant leaves. For biological and physical background information, I would like to know whether leaves grow by adding cells at the edge, at the center or in a completely different way. Since I need to confirm any information I get, please do not write opinions or guesses. It would be great if someone could find a reliable source with link since all my researches didn't lead to a good answer to this question.Thanks in advance!

Answer 1

Cell expansion and division are both a part of leaf growth, and they happen in different ways throughout the leaf structure. The young leaf's primary formation is initially aided by the widespread cell division. As the leaf ages, cell expansion takes over as the primary mechanism propelling leaf enlargement, while cell division is primarily restricted to particular areas, such as the leaf base. Cells grow larger to support overall growth as this expansion takes place throughout the leaf blade. Consequently, leaf growth entails a coordinated process of cell division and expansion throughout the leaf rather than just the addition of cells at the center or edges.