Washington has demanded his release.
His trial is one of several legal cases which have strained relations between Turkey and the United States, who are also at odds over US support for a Kurdish militia in northern Syria which Turkey considers a terrorist organization.
Brunson, who has lived in Turkey for 23 years, rejects the accusations.
The lawyer for a USA pastor who goes on trial in Turkey on Monday over alleged links to a group accused of orchestrating a failed military coup said the preacher had been arrested for his Christian faith. North Carolina Senator Thom Tillis and Sam Brownback, U.S. ambassador-at-large for religious freedoms were observing the trial, Turkey's private Dogan news agency reported. -Turkish relations would be affected if Brunson remained in prison. The prosecution is seeking a jail sentence of up to 35 years.
The American Center for Law and Justice, a conservative Christian group in the US, has called Brunson a "hostage of the Turkish government".
Erdogan fired back at Washington, demanding that the USA return Gulen to Turkey. I want the truth to come out", Reuters quoted Brunson as telling the court. "I do not accept the charges mentioned in the indictment.
"Give him (Gulen) to us, and we will try (Brunson) and return him", Erdogan said a year ago.
The indictment - based on the testimonies of witnesses, including three secret ones, and alleged digital evidence - claims the pastor worked to convert Kurds to Christianity to sow discord.
The Turkish government blames the cleric Gulen, who lives in Pennsylvania, for masterminding an attempted coup in 2016.
"We do not have a united policy with the United States on the YPG issue, and Turkey's stance has not changed".
For Brunson, the Chairman flew on Sunday in the Resurrection Church in Izmir, and his wife Norine read a message out at that he spoke about quiet and this darkness with his detention.