Abstract
Maize (Zea mays L.) is a moderately salt-sensitive crop, yet escalating soil salinization increasingly threatens its growth and productivity. To unravel the genetic basis of salt tolerance in maize, this study utilized a recombinant inbred lines (RILs) population comprising 139 lines derived from a cross between a salt-tolerant inbred line (HZ32) and a salt-sensitive inbred line (O167). By conducting quantitative trait locus (QTL) mapping for germination rate (GR) and seedling survival (SR) rate under salt stress, we identified eight QTLs, four QTLs associated with germination rate and four QTLs associated with survival rate. Notably, qGR3-1 was consistently detected for germination rate across two replicates, while qSR4-2 and qSR10-2 were stably identified for seedling survival rate in both replicates. Concurrently, time-course dynamic transcriptome analysis under salt stress (0, 6, 12, and 24 h post-treatment) was performed on HZ32 and O167. This revealed that differentially expressed genes (DEGs) between the two parents were significantly enriched in pathways including secondary metabolite biosynthesis, phenylpropanoid biosynthesis, and photosynthesis-suggesting that maize salt tolerance may arise from coordinated regulation of secondary metabolism, phenylpropanoid accumulation, and photosynthetic efficiency". Furthermore, by integrating the QTL intervals of qSR4-2, qSR10-2 and the dynamic transcriptome data, three candidate genes were identified: one gene (Zm00001d051877) from qSR4-2 and two genes (Zm00001d025874 and Zm00001d026005) from qSR10-2. Collectively, this study not only provides an important salt tolerance germplasm (HZ32) but also identifies promising genetic targets for enhancing maize seedling salt tolerance through breeding approaches. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-026-01638-9.