Characterization of TBP and TAFs in Mungbean (Vigna radiata L.) and Their Potential Involvement in Abiotic Stress Response

Abstract

The TATA-box binding protein (TBP) and TBP-associated factors (TAFs) constitute the transcription factor IID (TFIID), a crucial component of RNA polymerase II, essential for transcription initiation and regulation. Several TFIID subunits are shared with the Spt–Ada–Gcn5–acetyltransferase (SAGA) coactivator complex. Recent research has revealed the roles of TBP and TAFs in organogenesis and stress adaptation. In this study, we identified 1 TBP and 21 putative TAFs in the mungbean genome, among which VrTAF5, VrTAF6, VrTAF8, VrTAF9, VrTAF14, and VrTAF15 have paralogous genes. Their potential involvement in abiotic stress responses was also investigated here, including high salinity, water deficit, heat, and cold. The findings indicated that distinct genes exerted predominant influences in the response to different abiotic stresses through potentially unique mechanisms. Specifically, under salt stress, VrTBP, VrTAF2, and VrTAF15–1 were strongly induced, while VrTAF10, VrTAF11, and VrTAF13 acted as negative regulators. In the case of water-deficit stress, it was likely that VrTAF1, VrTAF2, VrTAF5–2, VrTAF9, and VrTAF15–1 were primarily involved. Additionally, in response to changes in ambient temperature, it was possible that genes such as VrTAF5–1, VrTAF6–1, VrTAF9–2, VrTAF10, VrTAF13, VrTAF14b–2, and VrTAF15–1 might play a dominant role. This comprehensive exploration of VrTBP and VrTAFs can offer a new perspective on understanding plant stress responses and provide valuable insights into breeding improvement.