A novel bacterial infection mechanism in plants

May 17, 2017

Possibilities for the development of a breakthrough anti-infection chemical

The major route of bacterial infection in plants is through open stomata on leaves. A plant can guard against such infections with closed stomata, but pathogenic bacteria can respond by secreting virulence factors that reopen the stomata to invade the plant. Because pathogenic factors work by using the plant's resistance mechanisms for insect damage, the inhibition of the machinery of infection could lead to the reduction of the plant's resistance to insect. This is a "dilemma" of sorts to inhibit the bacterial infection in plant.

A collaborative research group including Tohoku University, RIKEN CSRS and Nagoya Institute of Technology used their newly developed stereoisomeric analogs of the virulence factor coronatine for the biological analysis in combination with alkyne-tagged Raman imaging (ATRI) to carry out a localization analysis of coronatine in Arabidopsis stomatal guard cells. The analysis showed that coronatine uses a novel mechanism related to endoplasmic reticulum (ER) for re-opening stomata. Researchers succeeded in ATRI of plant cells for the first time by using arc-6 Arabidopsis mutants, which display severe abnormalities in chloroplast division.

Since this novel mechanism does not affect the plant's resistance to insect, these findings suggest potential for developing a breakthrough chemical that prevents pathogenic bacterial infections without sacrificing resistance to insect in plants.

Original article
ACS Central Science doi:10.1021/acscentsci.7b00099
M. Ueda, S. Egoshi, K. Dodo, Y. Ishimaru, H. Yamakoshi, T. Nakano, Y. Takaoka, S. Tsukiji, M. Sodeoka,
"Noncanonical Function of a Small-Molecular Virulence Factor Coronatine against Plant Immunity: An In Vivo Raman Imaging Approach".
Mikiko Sodeoka
Group Director
Catalysis and Integrated Research Group