How to make the label italic when perfrom Clustering analysis with fviz_dend()

[Johnme24]

I am new to factoextra package, and have benefited a lot from the fviz_dend() function. However, I wanna know "How to make the label display in italic", because the labels represents species and are required to be manifest in italic. I tried to use edit(fviz_dend) to find the possible "font", but I failed. Would anyone help me, much thanks!