| Hauptseite > Publikationsdatenbank > Dissecting the response to beneficial microbes during improvement of plant abiotic stress tolerance, focusing on limiting nutrients or temperature and monitored with non-invasive phenotyping and molecular approaches |
| Conference Presentation (Invited) | FZJ-2022-02506 |
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2022
Abstract: We present studies where use of plant growth promoting bacteria resulted in improved plant performance under limited nitrogen (N) or phosphorus (P) in Brachypodium dystachion (Bd) - a model plant for cereals, or for elevated temperature in Arabidopsis thaliana (At). Roots, responsible for plant nutrient uptake, vary thorough space and time [1] and were thus analyzed using non-invasive root phenotyping [2-4] for temporal resolution of the plant-microbe interaction. In the case of N, Bd inoculated with Herbaspirillum seropedicae (Hs) in EcoFABs [4] had longer primary roots and shorter root hairs independent of N, with stronger changes at low N. A mass-balance calculation showed that at high N, Hs provided 11% of total plant N from sources other than seed or nutrient solution. Time-resolved phenotypic and molecular data indicates two modes of action: At 5 mM Bd benefits through Hs N-fixation; at 0.5 mM Hs promotes N-uptake from the root medium. When using Pseudomonas koreensis, growth promotion was noted primarily in Bd on low N, confirmed via 15N signatures indicating N-fixation, proteomics, and C:N ratio changes. In the case of P limitation and low temperature, plant biomass was higher in Bd inoculated with a Azospirillum brasilense (Ab). Root phenotyping [2, 5], showed increased root length and changes in root architecture through time, pin-pointing the time of growth promotion after inoculation. Polar metabolite and lipid fluctuations during early plant development indicated that at the beginning, Ab elicited a defense response in Bd roots, while at later stages Ab reduced the stress caused by phosphorus deficiency [6].Finally, Paraburkholderia phytofirmans (PsJN) improved plant performance in At at 30°C, in an advanced version of GrowScreen-Agar [3]. Root responses to PsJN were dynamic and showed increases in lengths and growth rates, and changes in root angles under both temperatures. The onset of growth promotion was at day 12 post inoculation, and was greater in plants with PsJN at ambient temperature vs. 30°C. Importantly, the improvement at 30°C significantly reduced heat stress responses. Analysis of shoot biomass correlated to the root results. Lipidomic measurements to elucidate systemic changes, e.g. of membrane lipids, are ongoing.
Keyword(s): Basic research (1st) ; Biology (2nd)
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