The nuclear factor Y (NF-Y) transcription factor complex is important in plant growth, development and stress response. Information regarding this transcription factor complex is limited in cassava (Manihot esculenta). In this study, 15 MeNF-YAs, 21 MeNF-YBs and 15 MeNF-YCs were comprehensively characterized during plant defence.
The regulation of MeNF-Ys in response to Xam indicated their possible roles in response to cassava bacterial blight. Protein–protein interaction assays identified the heterotrimeric NF-Y transcription factor complex (MeNF-YA1/3, MeNF-YB11/16 and MeNF-YC11/12). Moreover, the members of the heterotrimeric NF-Y transcription factor complex were located in the cell nucleus and conferred transcriptional activation activity to the CCAAT motif. Notably, the heterotrimeric NF-Y transcription factor complex positively regulated plant disease resistance to Xam, confirmed by a disease phenotype in overexpressing plants in Nicotiana benthamiana and VIGS in cassava. Consistently, the heterotrimeric NF-Y transcription factor complex positively regulated the expression of pathogenesis-related genes (MePRs).
He et al. conclude that the NF-Y transcription factor complex (MeNF-YA1/3, MeNF-YB11/16 and MeNF-YC11/12) characterized here was shown to play a role in transcriptional activation of MePR promoters, contributing to the plant defence response in cassava.