Hello,
If they married prior to the start of Civil Registration in Scotland ( 1 Jan 1855) then there may or may not be an Old Parish Record (OPR) of their marriage, the record simply may not have survived, or may be irregular or may not have been Established Church of Scotland (be nonconfomist). Records can be sparse. Even if a record is found, you are unlikely to to find the parents names.
Were they the couple in Bladnoch Village, Wigown 1861? Son John born abt 1850/51 in Kells, kirkcudbrighshire. Mother Helen born abt 1833 Parton,Kirkcudbrighshire ( if so, wondering - what is the connect to Dumfrieshire where this topic is posted)
If the Wigtownsh. family is right: , your first best bet is to purchase the Birth Cert of daughter
Mary Johnston, born 21 May 1855, Wigtown
Father: James Johnston and Mother Helen Rutherford
There is extra information on 1855 Births, including information on Parents Marriage, parents birthplaces and other children of the couple.
Aside from this, if James and Ellen/Helen died in Scotland after 1855, their death records should state their parent's names ( if the informant knew them). Also, the Scottish naming pattern can be applied to their children - to see if that has clues.
Cheers
AMBLY
