Large plant third son leaves film studio's beauty queen? (6,4)

I believe the answer is:

missel tree

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'third son leaves film studio's beauty queen?' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'large plant' is the wordplay.
'large' becomes 'missel' (I can't explain this - if you can you should believe this answer much more).
'plant' becomes 'tree'.
'missel'+'tree'='MISSEL-TREE'

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