RT Journal Article SR Electronic T1 A group of nuclear factor Y transcription factors are likely sub-functionalized in the endosperm development of monocot JF bioRxiv FD Cold Spring Harbor Laboratory SP 149047 DO 10.1101/149047 A1 E. Zhiguo A1 Li Tingting A1 Zhang Huaya A1 Liu Zehou A1 Deng Hui A1 Wei Xuefeng A1 Wang Lei A1 Niu Baixiao A1 Chen Chen YR 2017 UL http://biorxiv.org/content/early/2017/06/12/149047.abstract AB Nuclear factor Y (NF-Y), also known as Heme Activator Protein or CCAAT-binding factor, is a heterotrimeric transcription factor that consists of three subunits, NF-YA, NF-YB, and NF-YC. Although NF-Ys play multiple roles in plant development, their functions during endosperm development are not well understood. In this study, we identified eight rice (Oryza sativa) NF-Y encoding genes, including OsNF-YA8, OsNF-YB1,9, and OsNF-YC8,9,10,11,12, which predominantly express in the endosperm. Interestingly, their closest homologs could only be found in monocot species and these genes also showed an endosperm-preferential expression pattern, which suggest that the phylogenetically related group of NF-Ys may be involved in the regulation of endosperm development. A systemic analysis of the interactions between rice endosperm-preferential NF-Ys in yeast revealed that NF-YBs and NF-YCs could interact with each other in all the combinations that we tested. OsNF-YA8 is a recently evolved NF-YA in rice. NF-YA does not usually interact with NF-YB monomers in plants; however, OsNF-YA8 could interact with OsNF-YB9. Our results also indicated that the endosperm-preferential OsNF-YBs, as well as the OsNF-YCs, could interact with some endosperm-specific ERFs of rice. Unlike the OsNF-YC8,9,10, OsNF-YB1,9 or OsNF-YC11,12 alone lacks transcriptional activation activity. However, the dimers they formed displayed transcriptional activation activities. Considering that mutated OsNF-YB1 can severely impair endosperm development in rice, our findings strongly suggest that there is a group of phylogenetically conserved NF-Ys that have differentiated in monocots to regulate endosperm development.