gsettings
Practical reference for the gsettings command used to list, read, and modify GNOME desktop settings from the command line, including common examples for Gedit preferences
Check list
gsettings list-recursively
Examples of how to change settings with gsettings
Enable current line highlighting in Gedit
gsettings set org.gnome.gedit.preferences.editor highlight-current-line true
Set Gedit color scheme to cobalt
gsettings set org.gnome.gedit.preferences.editor scheme 'cobalt'
Disable use of the default editor font
gsettings set org.gnome.gedit.preferences.editor use-default-font false
Set a custom editor font in Gedit
gsettings set org.gnome.gedit.preferences.editor editor-font 'Cantarell Regular 12'