Functional analysis of the heterotrimeric NF-Y transcription factor complex in cassava disease resistance

Area of Science:

• Plant molecular biology
• Plant-pathogen interactions
• Transcription factor research

Background:

• Nuclear Factor Y (NF-Y) is crucial for plant growth and stress responses.
• Limited information exists on NF-Y in cassava (Manihot esculenta).
• This study comprehensively characterizes cassava NF-Y subunits (MeNF-YAs, MeNF-YBs, MeNF-YCs) in plant defense.

Purpose of the Study:

• To investigate the role of NF-Y transcription factors in cassava's response to bacterial pathogens.
• To identify specific MeNF-Y subunits involved in plant defense mechanisms.
• To elucidate the function of the heterotrimeric NF-Y complex in cassava bacterial blight resistance.

Main Methods:

• Gene expression analysis of MeNF-Ys during Xanthomonas axonopodis pv. manihotis (Xam) infection.
• Yeast two-hybrid assays to determine protein-protein interactions within the NF-Y complex.
• Virus-induced gene silencing (VIGS) in cassava to assess in vivo gene function.
• Expression analysis of pathogenesis-related genes (MePRs).

Main Results:

• MeNF-Ys expression is regulated by Xam, suggesting a role in cassava bacterial blight response.
• Specific MeNF-Y subunits (MeNF-YA1/3, MeNF-YB11/16, MeNF-YC11/12) form a heterotrimeric complex.
• The identified NF-Y complex localizes to the nucleus, activates the CCAAT motif, and enhances disease resistance in cassava and Nicotiana benthamiana.
• Overexpression and VIGS confirmed the positive regulation of plant defense against Xam.

Conclusions:

• The characterized NF-Y transcription factor complex (MeNF-YA1/3, MeNF-YB11/16, MeNF-YC11/12) plays a vital role in cassava plant defense.
• This complex contributes to plant immunity by activating pathogenesis-related gene promoters (MePRs).
• The findings highlight the NF-Y complex as a key regulator of transcriptional activation in cassava's response to bacterial pathogens.