Tex. Elec. Code § 142.007
The minimum number of signatures that must appear on a candidate's petition is:
(2) for a district, county, or precinct office, the lesser of:
(B) five percent of the total vote received in the district, county, or precinct, as applicable, by all candidates for governor in the most recent gubernatorial general election, unless that number is under 25, in which case the required number of signatures is the lesser of:
Acts 1985, 69th Leg., ch. 211, Sec. 1, eff. Jan. 1, 1986.