Download Ikuko Hara-Nishimura

SPEAKER AT:
October, 2nd and 3rd , 2013, Barcelona
Ikuko Hara-Nishimura, Professor at Kyoto University, Kyoto, Japan
Ikuko Hara-Nishimura received her Ph.D. in Osaka University. She was a research
assistant in Natural Institute for Basic Biology between 1990 and 1997, and then became
associate professor until 1999. Since 1999 Ikuko Hara-Nishimura is Professor at Kyoto
University. She received the Japanese Society of Plant Physiologists Award in 2013, the
Prize for Science and Technology and the Commendation for Science and Technology by
MEXT in 2007, and the Chunichi Cultural Prize in 2006. She currently is member of
Review Panel of MEXT (Government of Japan). She also was member of the Expert Panel
on Basic Policy of Council for Science and Technology Policy at Cabinet Office
(Government of Japan) between 2007 and 2011; the Review Panel of Ministry of
Agriculture, Forestry and Fisheries and Research Council between 2005 and 2009, and the
Review Panel at Council for Science and Technology Policy in 2007 and 2008.
SPEAKER AT:
October, 2nd and 3rd , 2013, Barcelona
Endomembrane Systems Responsible for Defense Strategies of Plants
Plant endomembranes including vacuoles and endoplasmic reticulum dynamically move
and change their shapes within the cells. Previously, we reported that plants use vacuoles
for cell autonomous plant immunity in two different ways. The first way involves fusion of
vacuolar membrane and plasma membrane, which is triggered by the a virulent bacteria
infection and allows vacuolar defense proteins to be discharged into the extracellular space
where the bacteria proliferate. The fusion of vacuolar and plasma membranes is induced in
a proteasome-dependent manner. The second way is associated with vacuolar membrane
collapse followed by the release of vacuolar hydrolytic enzymes into the cytosol, resulting
in rapid and direct cell death. This way is effective in the digestion of viruses proliferating
in the cytosol. Intriguingly, both vacuole-mediated immune systems induce hypersensitive
cell death by using caspase-like activities: caspase-3-like activity (DEVDase activity) of
proteasome subunit PBA1 causes the membrane fusion, while caspases-1-like activity
(YVADase activity) of VPE causes the vacuolar membrane collapse. In this meeting, we
also touch on another ingenious two-compartment immune system, in which betaglucosidases in the ER bodies of epidermal cells of roots and the vacuoles of myrosin cells
of leaves are sequestered from their glucosinolate substrate. When cells are ruptured by
herbivores, myrosinase converts the substrates into a toxic compound. These results
provide an idea that plants use the vacuoles differently depending on the type of
pathogenic organisms.