blight leads to browning and sometimes the death of important crops. Most
famously, late blight of potato resulted in the Great Irish Famine. Blight
continues today, affecting crops around the world. One form of bacterial blight
(caused by Pseudomonas cannabina pv. alisalensis or Pcal) affects cruciferous plants, such
as cabbage, as well as green manure crops like oats.
Pcal is known to use virulence factors, but these factors have not been
investigated until recently, when scientists from the University of Tsukuba in
Japan conducted research into coronatine (COR) function, one of the pathogen’s well-known
virulence factors. A phytotoxin, COR is known to aid pathogen growth and lesion
formation or expansion by reopening stomata, which makes the plant more
vulnerable, but its exact role in Pcal infection was unknown.
Investigating the interaction between Pcal and cabbage and oats, the
University of Tsukuba scientists found that COR does reopen the stomata but
that it also suppresses salicylic acid, which plants use to protect themselves
from pathogens. Through these actions, COR helps Pcal successfully
infect the plant, leading to bacterial blight.
“Because of the unique Pcal characteristics, which can infect both dicot
and monocot plants, we were able to investigate COR functions in the
interactions between the pathogen and two very different plants: cabbage and
oat,” explained scientist Nanami Sakata, who hopes that this research can be
used to develop bacterial pathogens protection methods or chemicals that target
pathogen infection processes. “We believe that the reveal of this virulence
mechanism can lead to the development of new disease control strategies.”
For more information, read “Coronatine
Contributes to Pseudomonas cannabina pv. alisalensis Virulence by
Overcoming Both Stomatal and Apoplastic Defenses in Dicot and Monocot Plants”
published in MPMI, a fully open access journal.