This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Дata Availability: The data that support the findings of this study are available in NCBI Gene Expression Omnibus at with the accession numbers GSE77396 for ENA1ox RNA-seq, GSE80568 for ABA treatment RNA-seq, GSE90004 for abi5-1 RNA-seq, GSE60143 for ABI5 ChIP-seq, GSE97288 for ENAP1 ChIP-seq.ДЇunding: This work was supported by grants from the National Institutes of Health (to H.Q.) (NIH-2R01GM115879). Received: SeptemAccepted: NovemPublished: December 15, 2021Д¬opyright: В© 2021 Zhao et al. PLoS Genet 17(12):Д®ditor: Li-Jia Qu, Peking University, CHINA Overall, our research reveals a new molecular mechanism by which ENAP1 regulates H3K9 acetylation and mediates the positive feedback regulation of ABI5 to inhibit seed germination.Д¬itation: Zhao B, Wang L, Shao Z, Chin K, Chakravarty D, Qiao H (2021) ENAP1 retrains seed germination via H3K9 acetylation mediated positive feedback regulation of ABI5. In the enap1 deficient mutant, H3K9Ac enrichment and the binding activity of ABI5 in its own promoter region, along with ABI5 transcription and protein levels are all reduced while in the abi5-1 mutant, the H3K9Ac enrichment and ENAP1 binding activity in ABI5 promoter are decreased, suggesting that ENAP1 and ABI5 function together to regulate ABI5- mediated positive feedback regulation. ABI5 gene is directly regulated by ENAP1 and ABI5. ABA enhances H3K9Ac enrichment in the promoter regions as well as the transcription of target genes co-bound by ENAP1 and ABI5, which requires both ENAP1 and ABI5. The hypersensitivity to ABA of ENAP1ox seeds germination is recovered by the abi5 null mutation. Here, we show that ENAP1 interacts with ABI5 and they co-bind to ABA responsive genes including ABI5 itself. However, the molecular mechanism of how ABI5 and histone acetylation coordinate to regulate gene expression during seed germination is still ambiguous. The transcription factor ABI5 plays an essential role in ABA- inhibited seed germination. Histone acetylation is involved in the regulation of seed germination.

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