Is there a single word that means "To commit treason"?

Is there a word I can use in place of 'committing treason' in the sentence

"The corporal was on trial for committing treason."

so the sentence reads

"The corporal was on trial for _____ing"

Treason is a defined legal concept, so has a definite meaning. There's no verb form of treason. Use

The corporal was on trial for treason.

The verb is the same as the noun - 'treason'. But the verb form is stated by the OED to be 'rare'.

13.. K. Alis. 723 Thy fadir hastow tresond here! c1330 R. Mannyng Chron. (1810) 105 Þei wer fulle wele knowen, þat wild haf tresond him. c1374 Chaucer Troilus & Criseyde iv. 410 (438) To traysen [v.r. trassen] a wight þat trewe is vn-to me. 1890 L. Lewis Proving of Gennad xv. 104 Ere morning, thou shalt know who treasons thee. (Hide quotations)