Chitosan-mediated mitigation of salt stress in wheat (Triticum aestivum L.) under tissue culture conditions

Abstract Wheat ( Triticum aestivum L.) stands as a pivotal cereal crop and ranks among the most extensively cultivated species worldwide. It is productivity, however, is markedly hindered by both abiotic and biotic stressors, with salinity emerging as a predominant abiotic challenge in agricultural systems. Salinity is a pervasive issue in arable lands, necessitating the development of sustainable strategies to mitigate it is adverse effects while prioritizing environmental sustainability. Chitosan, a derivative of chitin, has garnered as an eco-friendly agent for alleviating salt stress due to it is biocompatibility and environmental safety. Studies have demonstrated that chitosan application can enhance plant growth parameters and bolster antioxidant defenses under saline conditions. In this study, the effects of varying chitosan concentrations (0, 1, 2, 4 mg/mL) and exposure durations (2, 4, 8 h) were investigated under different salinity levels (0, 75, 150, 225 mM) using mature embryos of the salinity-sensitive Kırik wheat variety. Key in vitro parameters assessed included the embryogenic callus formation rate (CFR), responding embryogenic callus rate (RECF), shoot formation rate (SFR) root formation rate (RFR), and the number of plants per explant (NP). The findings revealed that chitosan effectively mitigates salt stress. Notably, a 1 mg/mL chitosan concentration significantly improved CFR, RECR, and SFR, whereas a 4 mg/mL concentration was more effective for RFR and NP. The responses of RECR and CFR to salt stress exhibited similar patterns. Analysis of variance indicated that the optimal duration for a 1 mg/mL chitosan treatment was 4 h, while for the 4 mg/mL concentration, a 2-hour exposure was more effective, suggesting that shorter treatment durations are more beneficial at higher chitosan concentrations. Despite the promising results, the limited literature on the role of chitosan in tissue culture highlights the novelty of this research, emphasizing it is potential to make a unique contribution to the field. The findings of this study provide valuable insights for enhancing wheat’s resistance to salinity stress through chitosan treatment, offering practical applications in developing more resilient crop varieties.