A group of nuclear factor Y transcription factors are sub-functionalized during endosperm development in monocots

• Published in: Journal of experimental botany Vol. 69; no. 10; pp. 2495 - 2510
• Main Authors: E, Zhiguo, Li, Tingting, Zhang, Huaya, Liu, Zehou, Deng, Hui, Sharma, Sandeep, Wei, Xuefeng, Wang, Lei, Niu, Baixiao, Chen, Chen
• Format: Journal Article
• Language: English
• Published: UK Oxford University Press 27.04.2018
• Subjects: Research Papers; nuclear factor Y transcription factor; Endosperm; protein interaction; phylogenic analysis; rice; transcription factors
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ery087

A group of phylogenetically conserved nuclear factor Y transcription factors are preferentially expressed in the endosperm and probably play essential roles in endosperm development for rice and other monocots. Abstract Nuclear factor Y (NF-Y) is a heterotrimeric transcription factor that consists of three subunits, NF-YA, NF-YB, and NF-YC. Gene functions of NF-Ys during endosperm development are not well understood. In this study, we identified eight rice NF-Y-encoding genes, namely OsNF-YA8, OsNF-YB1,9, and OsNF-YC8,9,10,11,12, that are predominantly expressed in the endosperm. Interestingly, the close homologs of these OsNF-Ys are present only in monocot species and are also preferentially expressed in the endosperm, suggesting that they have roles in the regulation of endosperm development. A systemic analysis of interactions between rice endosperm-preferential NF-Ys in yeast revealed that OsNF-YBs and OsNF-YCs could interact with each other. We also found that the endosperm-preferential OsNF-YBs and OsNF-YCs could interact with some ethylene response factors (ERFs) of rice. Unlike OsNF-YC8,9,10, the members of OsNF-YB1,9 or OsNF-YC 11,12 showed no transcriptional activation when present alone. However, they displayed functional activity while in dimer form. In addition, OsNF-YB1-knockout lines showed significant changes in seed morphology, further confirming its role in endosperm development. Our findings provide evidence that a group of phylogenetically conserved NF-Ys is probably differentiated in monocots to regulate endosperm development.