Deciphering Salt Tolerance Key Genes in Maize Inbred Lines via Time-Series Transcriptomics and Machine Learning

A systematic evaluation of salt tolerance at the seedling stage was conducted using 143 maize inbred lines in this study. The results showed that salt stress significantly inhibited seedling growth and enabled the identification of several elite salt-tolerant inbred lines, including B114. Salt tolerance was significantly positively correlated with anti-oxidant capacity. Under salt stress, the highly salt-tolerant line B114 exhibited lower membrane damage, stronger reactive oxygen species scavenging capacity, and a significantly higher survival rate than the salt-sensitive line PHT55. Using random for-est-based machine learning, 50 core salt tolerance-related genes were unbiasedly identified from high-dimensional transcriptomic data. Functional enrichment analysis revealed that these genes were primarily involved in redox regulation, ion homeostasis maintenance, and stress signal transduction pathways. This study established a maize salt tolerance evaluation system closely aligned with field conditions and demonstrated that coordi-nated temporal transcriptional regulation represents a core molecular mechanism under-lying high salt tolerance in maize. The elite salt-tolerant germplasm and key candidate genes identified in this study provide valuable genetic resources and a theoretical founda-tion for molecular breeding of salt-tolerant maize adapted to saline-alkaline soils.