FERONIA Modulates Translational Buffering Capacity of Ribosome-Associated Gene Module in Salt-Stressed Tomato Roots

Salt stress limits tomato productivity, yet how translational regulation contributes to root salt adaptation remains poorly understood. We integrated RNA-seq and ribosome profiling in wild-type (WT) and FERONIA (FER) mutant (fer) tomato roots under control and 150 mM NaCl conditions. In WT roots, the salt response was predominantly transcript-driven, but a 29-gene ribosome-associated module showed reduced RNA abundance alongside increased translational efficiency, indicating selective translational buffering. FER loss-of-function disrupted this balance, constitutively elevating ribosome occupancy of ribosome-associated genes while reducing basal expression of stress- and ion-transport-related genes; under salt treatment, fer also showed stronger ion-transport transcriptional responses but weaker translational efficiency responses of this module. WT salt stress further shifted ribosome allocation from the 5′ untranslated region (UTR) toward the coding sequence (CDS), an effect attenuated in fer, alongside positive coupling between uORF and CDS translational efficiency. Feature modeling identified sequence and structural predictors of uORF translation, including weaker local RNA folding near the start codon and specific amino acid and stop codon preferences. Together, these results reveal FER-associated changes in ribosome-associated translational buffering during tomato root salt responses.