Eukaryotic organisms organize their genetic material in chromatin rather than naked DNA. Efficient chromatin assembly is essential for all DNA-templated processes, including replication, transcription, and DNA repair. Our research focused on two major histone H3 deposition complexes: Chromatin Assembly Factor (CAF-1), which deposits canonical H3 on naked DNA immediately after replication during the S-phase in yeast and metazoans, and the Histone Regulator A (HIRA) complex, which is thought to incorporate the H3.3 variant in a replication-independent manner. By combining biochemical, genetic, genomic, and proteomic data, we revealed that CAF-1 activity might be associated with the maintenance of the histone variant H3.3 in Arabidopsis chromatin. Moreover, this CAF-1's potential function in H3.3 homeostasis may be particularly significant in the transcribed regions of the genome.