Genome-wide analysis of the CrRLK1L gene family in Puccinellia tenuiflora and functional study of PutFER1 in Arabidopsis underpinning salt tolerance

CrRLK1L receptor-like kinases have attracted significant interest in plant biology owing to their pivotal roles in development, stress response, and signal transduction. However, our understanding of their importance in the extreme saline-alkali tolerant mechanisms of the halophyte alkaligrass (<i>Puccinellia tenuiflora</i>) remains limited. In this work, we analyzed the homology and evolutionary relationships of the CrRLK1L gene family across 30 species. Through genome-wide analysis we identified 25 <i>PutCrRLK1L</i> genes, which revealed conserved malectin-like and kinase domain, unique intronless structures, and stress-/hormone-responsive promoter elements. Transcriptomic and RT-qPCR analyses revealed salinity response of nine <i>PutCrRLK1L</i> genes' expression in roots and leaves. Functional characterization of <i>FER</i> and antioxidant enzyme activities demonstrated that <i>PutFER1</i>-overexpressing Arabidopsis lines exhibited enhanced root growth under salt stress and reduced ROS accumulation compared to wild-type plants. These findings may open new avenues for research into halophyte-specific salt tolerance mechanisms and provide potential candidate genes for improving crop resilience to saline-alkaline soils.