tt2

Tt2 is a designation that can refer to multiple concepts across different fields. The most widely cited use is TT2, an Arabidopsis thaliana gene named Transparent Testa 2. In plant genetics TT2 encodes an R2R3-MYB transcription factor that participates in the regulation of flavonoid and proanthocyanidin biosynthesis in seed coats. TT2 functions as part of a regulatory MBW complex that includes the WD40-repeat protein TTG1 and the basic helix–loop–helix factor TT8. Through this network, TT2 activates genes involved in late steps of the flavonoid pathway, contributing to the accumulation of tannins and to seed coat pigmentation. Loss-of-function tt2 mutants exhibit reduced proanthocyanidins and paler seeds, reflecting altered seed coat chemistry. Expression of TT2 is typically restricted to developing seed coats, aligning with its role in seed coat tannin production.

In other domains, the acronym Tt2 may be used as a model code, project name, or identifier, and its meaning is context-dependent. If encountered in literature or documentation, the surrounding text generally clarifies whether it refers to a gene, a software version, a product model, or another entity.