Identified a new function of CERES in plant defense against potyviruses

Potyviruses represent one of the largest groups of plant viruses, with members infecting hosts in most, if not all, plant taxonomic families. It has been widely described that, despite viral translation being not cap-dependent, the host translation initiation factor eF4E isoforms participate in virus replication, movement, and possibly other steps in the virus life cycle.

In this article, generated in close collaboration between Dr. Ponz´s and Dr. Castellano´s lab at the Center for Plant Biotechnology and Genomics (CBGP-UPM / INIA), we reveal that CERES, a host protein that interacts with initiation factors of eIF4Es translation and that, under physiological conditions, regulates protein synthesis during the light cycle of plants (Toribio et al., 2019), induces different types of defense responses against TuMV (specifically veinal necrosis and full resistance) when it is overexpressed at high levels in N. benthaminana and in Arabidopsis. These defense phenotypes could be also observed when a CERES mutant devoid of its capacity to bind the eIF4Es is overexpressed.

All these data suggest that CERES, most likely due to its LRR nature, in the absence of other typical features of this kind of proteins, could act as an R protein, able to promote a range of different defense responses when it is highly overexpressed from viral constructs.