Transcriptomic insights into root-specific responses to salinity in Festuca rubra

Abstract

Soil salinity severely threatens global agriculture and turfgrass production. Festuca rubra L. (red fescue) is a widely cultivated turfgrass valued for its resilience and soil stabilization capacity. However, molecular responses to salt stress in red fescue remain poorly understood. This study aimed to elucidate the transcriptomic mechanisms underlying salt-induced inhibition of root growth in red fescue. Salt stress markedly inhibits root growth in F. rubra, whereas shoot length did not differ significantly between control and salt-treated plants. Transcriptomic analysis identified approximately 88,000 differentially expressed transcripts under salt stress. Upregulated genes were significantly enriched in functions related to folate-dependent methionine synthesis, suberin biosynthesis, beta-fructofuranosidase activity, and gibberellin response, suggesting metabolic, structural adjustments and hormone signaling may contribute to salt stress adaptation and root growth responses. In contrast, genes associated with sugar signaling, alkaloid biosynthesis and metabolism, mRNA splicing, the PI3K and ABA-related biological processes were downregulated, indicating broad reprogramming of metabolic, post-transcriptional, and signaling pathways. These findings shed light on the molecular basis of root-specific salt stress responses in F. rubra. This study enhances our understanding of its adaptive strategies under saline conditions.