Transcriptional Basis of Drought-Induced Susceptibility to the Rice Blast FungusMagnaporthe oryzae.
Plants are often facing several stresses simultaneously. Understanding how they react and the way pathogens adapt to such combinational stresses is poorly documented. Here, we developed an experimental system mimicking field intermittent drought on rice followed by inoculation by the pathogenic fungusMagnaporthe oryzae. This experimental system triggers an enhancement of susceptibility that could be correlated with the dampening of several aspects of plant immunity, namely the oxidative burst and the transcription of several pathogenesis-related genes. Quite strikingly, the analysis of fungal transcription by RNASeq analysis under drought reveals that the fungus is greatly modifying its virulence program: genes coding for small secreted proteins were massively repressed in droughted plants compared to unstressed ones whereas genes coding for enzymes involved in degradation of cell-wall were induced. We also show that drought can lead to the partial breakdown of several major resistance genes by affectingRplant gene and/or pathogen effector expression. We propose a model where a yet unknown plant signal can trigger a change in the virulence program of the pathogen to adapt to a plant host that was affected by drought prior to infection.
INRA, UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet Montpellier, France.
Przemyslaw
P
Bidzinski
SupAgro, UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet Montpellier, France.
Elsa
E
Ballini
INRA, UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet Montpellier, France.
Aurélie
A
Ducasse
INRA, UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet Montpellier, France.
Corinne
C
Michel
INRA, UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet Montpellier, France.
Paola
P
Zuluaga
Institute of Agricultural Biology and Biotechnology, National Research Council Milan, Italy.
Annamaria
A
Genga
Institute of Agricultural Biology and Biotechnology, National Research Council Milan, Italy.
Remo
R
Chiozzotto
INRA, UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet Montpellier, France.
Jean-Benoit
JB
Morel
Magnaporthe oryzae; drought; effectors; fungus; immunity; rice; stress combination