Perception of long-chain N-acyl homoserine lactones in plants

• Applicant: Professor Dr. Adam Schikora
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Plant Breeding and Plant Pathology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282634159

• Final Report Year: 2020

Final Report Abstract

Enhanced resistance against pathogens in model (Arabidopsis) and crop (barley) plants is of high interest. The knowledge on mechanisms of induced resistance improves our understanding of plant-microbe interactions and can be used in new breeding strategies, as part of microbe-assisted agriculture. The beneficial effects of bacterial quorum sensing molecules on resistance and plant growth have been shown in different plant species. The perception of bacterial quorum sensing molecules from the acyl homoserine lactone (AHL) group, results in different responses in plants. Several indices suggest differences in the response depending on the length of the acyl moiety of the AHL molecules, long-chained molecules were shown to induce resistance in a phenomenon called AHL-priming, whereas short-chained molecules modified the growth and architecture of roots. In this project we focused on the interaction between a particular long-chained AHL, oxo-C14-HSL, and Arabidopsis as well as barley plants. We revealed that the responsiveness to AHL depends on the genetic background. We were able to identify so called AHL-primable and AHL-nonprimable genotypes in both Arabidopsis and barley. Especially the findings in barley are of high importance for new breeding and plant protection strategies. The AHL-priming manifests itself in both plants via enhanced activity of MAP kinases, remodeling of cell walls and higher expression of defense-related genes. Moreover, we were able to identify a new AHL-interacting protein, which is required for AHL-dependent responses in Arabidopsis. The detailed mechanism of signal transduction will be the base for future projects. Very interesting was the genetic diversity in the ability to respond to AHL molecules as a priming stimulus. This observation bears the potential to discover further components related to the AHL-priming phenomenon in plants. Our momentary results suggest that the differences are down-stream of the interaction event with AHL molecules. Additional analysis is however required to pinpoint the exact differences between the AHL-primable and AHL-non-primable genomes.

Publications

• (2016) Beneficial effects of bacteria-plant communication based on quorum sensing molecules of the N-acyl homoserine lactone group. Plant Mol Biol. 2016 Apr;90(6):605-12
  Schikora A, Schenk ST, Hartmann A
  
• (2017) RNase E and RNase J are needed for S-adenosylmethionine homeostasis in Sinorhizobium meliloti. Microbiology. 2017 Apr;163(4):570-583
  Baumgardt K, Melior H, Madhugiri R, Thalmann S, Schikora A, McIntosh M, Becker A, Evguenieva-Hackenberg E
  
• (2018) Consistent associations with beneficial bacteria in the seed endosphere of barley (Hordeum vulgare L.). Syst Appl Microbiol. 2018 Jul;41(4):386-398
  Rahman MM, Flory E, Koyro HW, Abideen Z, Schikora A, Suarez C, Schnell S, Cardinale M
  
• (2018) Detection of Bacterial Quorum Sensing Molecules. Methods Mol Biol. 2018;1734:171-179
  Stein E, Schikora A
  
• (2019) Genetic Differences in Barley Govern the Responsiveness to N-Acyl Homoserine Lactone. Phytobiomes Journal Volume 3, Number 323 Jul 2019
  Shrestha A, Elhady A, Adss S, Wehner G, Böttcher Ch, Heuer H, Ordon F, and Schikora A
  
• (2019) Priming Is a Suitable Strategy to Enhance Resistance Towards Leaf Rust in Barley. Phytobiomes Journal Volume 3, Number 101 Jan 2019
  Wehner G, Kopahnke D, Richter K, Kecke S, Schikora A, and Ordon F