Plants get on PAR with poly( ADP ‐ribosyl)ation

Abstract

PARylation, was first described over 50 years ago. Since then, our understanding of the biochemistry and enzymology of this protein modification has significantly progressed. PARylation has long been associated with DNA damage and DNA repair as well as genotoxic stress [1,2]. However, over the last two decades this has expanded to chromatin remodelling, DNA replication, transcriptional regulation, telomere cohesion and mitotic spindle formation during cell division, intracellular trafficking and energy metabolism [1]. Most eukaryotes, except yeasts, have genes encoding poly (ADP-ribose) polymerases (PARPs) and poly (ADP-ribose) glycohydrolases (PARGs), and our knowledge on PARylation is primarily based on studies in metazoans. In plants, however, mechanistic understanding of the role of ADP-ribosylation in stress response is still lacking. In this issue of EMBO Reports, Feng et al [3] identify the first set of PARylated plant proteins and show that in vivo PARylation of one of these proteins, a factor named DAWDLE, is important for its role in plant immunity.

Roles of Nicotinamide Adenine Dinucleotide (NAD+) in Biological Systems

“…In plants, a mechanistic understanding of the role of ADP-ribosylation in stress response is still lacking, as well as in plant interaction with bacteria [74]. In 2016, Feng et al identified the first set of non-histone plant PARylated proteins, showing that in vivo PARylation of DAWDLE (DDL) is important in plant immunity [75,76]. DDL, a Forkhead associated (FHA) domain protein, domain that may bind to PAR polymer and to phosphothreonine, is involved in plant immunity, in a pathway downstream to PARP-domain activity and upstream to activation of gene expression of defense-related proteins [76].…”