S3.2: Priming of a the salicylic acid receptor NPR1 in the course of systemic acquired resistance (SAR)

Christiane Gatz & Xin Li & Yuelin Zhang

N-hydroxy-pipecolic acid (NHP) and salicylic acid (SA) are regulatory metabolites that play crucial roles in the plant defense program systemic acquired resistance (SAR). In the course of SAR, systemic leaves of locally infected plants are `primed´ to defend more efficiently against pathogen attack. Genetic and biochemical evidence suggests that NHP increases the sensitivity of the SA receptor NPR1 to SA (Nair et al., 2021), a concept that would explain the priming phenomenon.

Graphical abstract of the working hypothesis (Nair et al., 2021): In the absence of NHP, NPR1 has a relatively weak SA binding activity, which is increased in the presence of NHP.
In the past two funding periods, we have generated valuable genetic material (tagged NPR1 proteins in genetic backgrounds with basal or no SA) that are currently used to address the question of whether known SA-dependent post-translational modifications of NPR1 are primed by NHP. Moreover, the transgenic plants are used to analyse whether NHP induces posttranscriptional modifications that are different from those elicited by SA. Finally, novel NHP-specific protein-protein interactions will be identified using the concept of proximity-based labelling of proteins by an NPR1-TurboID construct. The advertised PhD position will build on this work. The project is closely connected to the project entitled “Functional characterization of known and candidate regulatory proteins that are (potentially) required for N-hydroxpipecolic acid (NHP)-induced gene expression”.
The project is done in collaboration with Profs. Yuelin Zhang and Xin Li at UBC Vancouver who address the research question of NHP perception and signalling by taking alternative approaches (Liu et al., 2020).

References

Nair, A., Goyal, I. Voß, E., Mrozek, P. , Prajapati, S., Thurow C., Tietze, L., Tittmann, K., and Gatz, C.: N-hydroxypipecolic acid-induced transcription requires the salicylic acid signaling pathway at basal SA levels. Plant Phys. 187, 2803–2819 10.1093/plphys/kiab433 (2021)

Liu, Y., Sun, T., Sun, Y., Zhang, Y., Radojicic, A., Ding, Y., Tian, H., Huang, X., Lan, J., Chen, S., Orduna, A.R., Zhang, K., Jetter, R., Li, X., and Zhang, Y. Diverse Roles of the Salicylic Acid Receptors NPR1 and NPR3/NPR4 in Plant Immunity. Plant Cell 32, 4002-4016. 10.1105/tpc.20.00499 (2020)

 

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