FERONIA controls ABA-mediated seed germination via the regulation of the kinase activity of CARK1

ABSTRACT: Seed germination is the initial step of the whole life cycle for an individual plant, and thus it needs to be tightly controlled to avoid the growth of plants under unfavorable conditions, such as high salinity and drought stress. It has been well known that ABA signaling pathway plays a key role in the regulation of seed germination. In this study, we found that FER, a receptor-like kinase that belongs to CrRLK1L subfamily, regulates seed germination under ABA or stress conditions via the modulation of ABI5 protein stability. Biochemical data indicate that FER interacts with and phosphorylates CARK1 protein, a receptor-like cytoplasmic kinase (RLCK) that is classified into the RLCK VIII subfamily. FER phosphorylates the Ser233 and Thr234 residues of CARK1, and these two residues are located in the activation loop and are required for the activation of CARK1. The CARK1 protein with the substitutions of these two amino acids to Ala exhibits reduced kinase activity and is not able to rescue the faster seed germination phenotype of cark1 mutant under ABA conditions. In both fer-4 and cark1 mutant, the ABA-triggered activation of SnRK2.6 and ABI5 protein accumulation were attenuated compared with the wild-type. Taken together, our study not only reveals a RLCK protein that functions directly downstream of FER to transduce external signals, but also provides a novel mechanistic insight into the understanding of seed germination regulation via ABA-mediated signaling pathways.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Plant Cell, Cell Culture

SUBMITTER: Chunzhao Zhao  

LAB HEAD: Chunzhao Zhao

PROVIDER: PXD047594 | Pride | 2024-09-14

REPOSITORIES: Pride