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 Sharma Sandeep A1 Wei Xuefeng A1 Wang Lei A1 Niu Baixiao A1 Chen Chen YR 2017 UL http://biorxiv.org/content/early/2017/06/19/149047.abstract AB Nuclear factor Y (NF-Y) 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 NF-Y encoding genes, including OsNF-YA8, OsNF-YB1,9, and OsNF-YC8,9,10,11,12, which predominantly express in the rice endosperm. Interestingly, the closest homologs of these OsNF-Ys are present only in the monocot species. All the genes are preferentially expressed in the endosperm, suggesting their roles 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. OsNF-YA8 is a recently evolved NF-YA in rice. Generally, NF-YA does not interact with NF-YB monomers in plants; however, in the present study, we found that OsNY-YA8 interacts with OsNF-YB9. Our results also indicated that the endosperm-preferential OsNF-YBs and OsNF-YCs could interact with some ethylene response factors (ERFs) of rice. Unlike the OsNF-YC8,9,10, the members of OsNF-YB1, 9 or OsNF-YC 11 and 12 showed lack of transcriptional activation when present alone. However, they displayed functional activity while in dimer form. In addition, OsNF-YB1 knockout lines showed significant changes in the seed morphology, further confirms its role in endosperm development. Our findings have provided strong evidences that the group of phylogenetically conserved NF-Ys are differentiated in monocots to regulate the endosperm development.