TOMATO FERTIGATION MANAGEMENT UNDERPINS A PHYSIOLOGICAL AND MOLECULAR REPROGRAMMING UNDER SALT STRESS

Agricultural crops are often exposed to concurrent environmental stresses, with soil salinization and intensive fertilization representing two major threats to sustainable food production. Here, we investigated the effect of nitrogen availability on salinity tolerance in tomato ( Solanum lycopersicum ) through integrated physiological, agronomic, and transcriptomic analyses. Our results confirm that salinity-induced declines in chlorophyll content were mitigated by moderate nitrate reduction, while vegetative development remained largely unaffected. Likewise, reproductive traits under moderate nitrate supply were comparable to those observed in fully fertilized plants. Interestingly, fruit quality traits in terms of sugars and lycopene content, were enhanced particularly under salinity combined with reduced nitrate supply. Consistent with these physiological responses, transcriptomic analyses across the different nitrate regimes revealed extensive salinity-induced transcriptional reprogramming, with the largest response observed under moderate nitrate supply. Together, these findings highlight the potential of precise fertilization management to improve both productivity and fruit quality in saline environments.