Project name: A role of PSK-CPK28-GS2 signalling in optimizing growth and defence in tomato

Description: Phytosulfokine (PSK) is a plant pentapeptide hormone that fulfills a wide range of functions. Although it has been frequently reported to function in the inverse regulation of growth and defence in response to (hemi)biotrophic pathogens, the mechanism involved remains largely unknown. Using tomato (Solanum lycopersicum) and Pseudomonas syringae pv. tomato (Pst) DC3000 pathogen as a system, we present compelling evidence that the tomato PSK receptor PSKR1 interacts with the calcium-dependent protein kinase CPK28, which phosphorylates the key enzyme of nitrogen assimilation glutamine synthetase GS2 at two sites (S334 and S360 sites). These post translational modifications uncouple the two PSK-induced effects on defence responses and on growth regulation, respectively. The discovery of these sites will inform breeding strategies designed to optimize the growth-defence balance. The concept that such peptide hormones can regulate plant growth and resistance in a compatible manner is attractive, not least because crop yields and fitness can be optimized simultaneously in global climate-change era.Overall design: An RNA-seq analysis was performed to further investigate how phosphorylation at the GS2 S334 site regulates plant defences. In these studies, tomato leaves GS2 and GS2S334A lines were sampled at 24 hpi in the absence or presence of Pst DC3000 inoculation. We also performed an RNA-seq analysis to investigate how phosphorylation at the GS2 S360 site regulates plant growth. Leaves from the GS2S360D lines and GS2 plants were sampled.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Agricultural

Last updated: 2022-10-04