There isn’t one specific verse, but begins with a logical thought process beginning with “All scripture is given by inspiration of God...”. Without digging out my textbooks and notes from Seminary, this site has some good info.
http://www.gotquestions.org/sola-scriptura.html
Because of sola scriptura, and my belief that anything extra-Biblical should be questioned, I disagree with many of our Baptist traditions. Haven’t even joined our local church because their Covenant prohibits “sale and use of intoxicating drinks as a beverage” — for one thing.