Heribert Hirt - Reprogramming of host and microbe metabolisms during beneficial plant-microbe interaction
March 2020
- Datum: 04.03.2020
- Uhrzeit: 14:00 - 15:30
- Ort: Central Building
- Raum: Seminar Room
- Gastgeber: Friedrich Kragler
Beneficial microbes can
enhance plant growth and provide abiotic and biotic stress tolerance to plants,
but their underlying mechanisms are poorly understood. Enterobacter sp. SA187
is a root endophytic bacterium that maintains growth and yield of various
monocot and dicot plants under various abiotic stress conditions. We compared
the metabolic wirings of Arabidopsis and SA187 in the free-living and
endophytic states. Upon plant interaction, massive changes in bacterial gene
expression in chemotaxis, flagellar biosynthesis, quorum sensing and biofilm
formation were observed. In both plant and bacteria, carbon, energy and sulfur
metabolisms were modified. The importance of the S metabolism in plant salt
stress was substantiated by observing that several sulfur metabolism mutants
show hypersensitivity to salt stress which can be partially rescued by SA187.
Moreover, salt stress-induced ROS accumulation i n Arabidopsis was suppressed
by SA187 in wild type and mutants of LSU2, a central chloroplast regulator
linking sulfur metabolism to SOD activity. Sulfur levels in chloroplasts are
monitored by the FRY1/SAL1 retrograde signaling pathway, mutants of which can
also be partially rescued by SA187. We showed that SA187 provides a small
sulfur metabolite to its host plant which regulates the ethylene signaling
pathway. Our data are consistent with the model that plant salt stress
tolerance is mediated by ethylene regulated sulfur metabolism and that
chloroplast retrograde signaling might play an important role during beneficial
plant-microbe interaction.
References:
- de Zelicourt A, Al-Yousif M, Hirt H.(2013) Rhizosphere microbes as essential partners for plant stress tolerance. Mol Plant 6:242-5.
- Andrés-Barrao C, Lafi FF, Alam I, de Zélicourt A, Eida AA, Bokhari A, Alzubaidy H, Bajic VB, Hirt H, Saad MM. (2017) Complete Genome Sequence Analysis of Enterobacter sp. S A187, a Plant Multi-Stress Tolerance Promoting Endophytic Bacterium.Front Microbiol. 8:2023
- de Zélicourt A, Synek L, Saad MM, Alzubaidy H, Jalal R, Xie Y, Andrés-Barrao C, Rolli E, Guerard F, Mariappan KG, Daur I, Colcombet J, Benhamed M, Depaepe T, Van Der Straeten D, Hirt H. (2018) Ethylene induced plant stress tolerance by Enterobacter sp. SA187 is mediated by 2-keto-4-methylthiobutyric acid production. PLoS Genet. 14(3):e1007273.