Arabidopsis thaliana TBP-associated factor 5 is essential for plant growth and development

The TATA binding protein-associated factor 5 (TAF5) is a subunit of TFIID and SAGA complexes involved in RNA polymerase II transcription initiation and histone acetylation. Although members of the putative SAGA complex in Arabidopsis such as GCN5 and ADA2b have important roles in plant development and abiotic stress responses, the function of other components of the Arabidopsis putative SAGA complex, like TAF5, is unknown. We used reverse genetics to elucidate the biological role of TAF5 in Arabidopsis thaliana. The absence of homozygote taf5 mutants indicated that AtTAF5 is an essential gene for the plant viability. Genetic approaches also revealed that AtTAF5 plays a critical role in regulatory mechanisms involved in male gametogenesis and pollen tube growth. Moreover, Arabidopsis taf5 heterozygous mutants displayed terminal flower-like phenotype, suggesting that TAF5 could be involved in molecular mechanisms that regulate indeterminate inflorescence meristems. Therefore, this work suggests that Arabidopsis TAF5 is necessary and sufficient for a complete plant life cycle.