Sucrose increases pathogenesis-related PR-2 gene expression in Arabidopsis thaliana through an SA-dependent but NPR1-independent signaling pathway.

Pathogenesis-related (PR) protein-coding gene expression was studied in Arabidopsis thaliana grown in liquid medium in the presence of sugars (sucrose or glucose). PR protein transcripts accumulated in the presence of sugar in the medium. A potential effect linked to osmolarity changes induced by sugar addition in the medium was ruled out using osmotica (NaCl or polyethylene glycol).