Defective cytokinin signaling reprograms lipid and flavonoid gene-to-metabolite networks to mitigate high salinity in Arabidopsis

ABSTRACT:

Cytokinin (CK) in plants regulates both developmental processes and adaptation to environmental stress. Arabidopsis histidine phosphotransfer ahp2,3,5 and type-B response regulator arr1,10,12 triple mutants are almost completely defective in CK signaling, and the ahp2,3,5 mutant was reported to be salt tolerant. Here, we demonstrate that the arr1,10,12 mutant is also more tolerant to salt stress than wild-type plants. A comprehensive metabolite profiling coupled with transcriptome analysis of the ahp2,3,5 and arr1,10,12 mutants was conducted to elucidate the salt tolerance mechanisms mediated by CK signaling. Numerous primary (e.g., sugars, amino acids and lipids) and secondary (e.g., flavonoids and sterols) metabolites accumulated in these mutants under both non-saline and saline conditions, suggesting that both pre- and post-stress accumulation of stress-related metabolites contribute to improved salt tolerance in CK-signaling mutants. Specifically, the level of oligosaccharides, amino acids [e.g., proline and gamma-aminobutyric acid], anthocyanins, sterols, and unsaturated triacyglycerols, were higher in the mutant plants than in wild-type plants. Notably, the reprograming of flavonoid and lipid pools was highly coordinated and concomitant with changes in transcriptional levels, indicating that these metabolic pathways are transcriptionally regulated by CK signaling. The discovery of the regulatory role of CK signaling on membrane lipid remodelling provides a greater understanding of CK-mediated salt tolerance in plants. This knowledge will contribute to the development of salt-tolerant crops with the ability to withstand salinity as a key driver to ensure global food security in the era of climate change.

INSTRUMENT(S): Liquid Chromatography MS - negative - reverse phase, Gas Chromatography MS - positive, Liquid Chromatography MS - positive - reverse phase

SUBMITTER: Mikiko Takahashi 

PROVIDER: MTBLS2532 | MetaboLights | 2021-11-25

REPOSITORIES: MetaboLights