The Multifunctional Anaphase Promoting Complex 7 (APC7) Gene Is Associated With Increased Plant Growth and Improved Resistance to DNA and RNA Viruses.

The anaphase promoting complex 7 (AtAPC7) is an APC/C subunit expressed in different organs of Arabidopsis thaliana and conserved among eukaryotes. A variant of the complete APC7 protein, containing its C-terminal region (named APC-CT), shows a high homology with a tobacco viral replication inhibitor (IVR-like) protein that reduces plant susceptibility to RNA viruses. Here, the role of the AtAPC7 gene was investigated by characterizing Arabidopsis plants overexpressing the full-length AtAPC7 (APC7^OE) and the C-terminal portion (APC7-CT^OE), by phenotypical, physiological and molecular approaches. APC7^OE plants showed improved growth of vegetative organs, earlier flowering and increased photosynthetic efficiency, CO₂ assimilation and productivity, compared with Col-0 control plants. Conversely, APC7-CT^OE plants showed reduced susceptibility to both RNA and DNA viruses, along with an improvement in plant growth, although not surpassing APC7^OE plants. Altogether, the data provide evidence for the role of the AtAPC7 in regulating cell division, expansion and differentiation, accompanied by an increase in photosynthetic capacity, resulting in enhanced plant biomass and seed yield. AtAPC7-CT might reduce growth-defence trade-offs, enabling plants to simultaneously defend themselves while promoting better growth. Our findings highlight the multifunctional role of AtAPC7, unveiling the potential of its orthologous genes as valuable biotechnological tools in important crops.