Sulfoxidation modification of NON-RIPENING (NOR) transcription factor is involved in the regulation of fruit ripening in tomato

ABSTRACT: Transcription factors (TFs) are important regulators of plant growth and development and responses to stresses. TFs themselves are also susceptible to multiple post-translational modifications (PTMs). Relatively, redox-mediated PTM of TFs in plants is not well elucidated. Here, we found that NON-RIPENING (NOR), a master TF regulating tomato fruit ripening, is a target of SlMsrE4 or SlMsrB2, the methionine sulfoxide reductase A and B in tomato, respectively. Methionine oxidation in NOR, i.e. sulfoxidation, or mimicking sulfoxidation by mutating Met138 to glutamine, leads to the decreased DNA-binding capacity and transcriptional regulatory activity in vitro. On the other hand, SlMsrE4 and SlMsrB2 can partially repair oxidized-NOR and restore its DNA-binding capacity. Genetic transformation of the nor mutant with NOR genomic DNA almost completely rescues the ripening phenotype. However, transformation of nor with NOR-M138Q, the mimicked methionine sulfoxidation, inhibits the restore of fruit ripening phenotype, and this is associated with the decreased DNA-binding and transcriptional activation of numerous ripening-related genes. Taken together, these findings uncover a novel mechanism by which Msr-mediated redox modification of NOR regulates the expression of ripening-related genes, thereby influencing tomato fruit ripening. To our knowledge, this is the first report that redox modification of TF regulates fruit ripening. nor is a NOR mutant, the phenotype is obstructed by maturity; NOR-12 is a rotational NOR in NOR mutant, the phenotype is a mature inhibition phenotype that basically restores nor mutant; Nor-18 is a rotation of NOR-M138Q in nor mutant, phenotype with the effect of restoring maturity, but the recovery efficiency is lower than the swing NOR.

ORGANISM(S): Solanum lycopersicum

PROVIDER: GSE140853 | GEO | 2020/05/22

REPOSITORIES: GEO