Abstract
Salt stress is a major abiotic stress causing adverse effects on plant growth and development. The aim of this study was to investigate the effect of NaCl stress on growth, stress indicator parameters (lipid peroxidation, chlorophyll content and proline content), yield, and the expression of heat shock proteins genes (Hsp17.8, Hsp26.3, Hsp70 and Hsp101) of five Jordanian durum wheat (Triticum durum) landraces. Plants were irrigated with tap water as control or 200 mM NaCl. Significant differences among the 5 Triticum durum landraces in terms of growth parameters, stress indicator parameters, and expression of heat shock proteins genes were observed. Salt stressed landraces demonstrated decreased growth, increased levels of stress indicator parameters, and upregulation in Hsp17.8, Hsp26.3, Hsp70 and Hsp101 expression. Landraces T11 and M23 showed the highest growth, lowest levels of stress indicator parameters, and high expression of heat shock protein genes under NaCl stress. Whereas, J2 and A8 landraces showed the lowest growth, highest levels of stress indicator parameters and low expression of heat shock protein genes under NaCl stress. In conclusion, NaCl stress caused significant reduction in growth parameters, increased level of lipid peroxidation and proline content and upregulation in heat shock proteins gene expression levels. Growth, stress indicator parameters and gene expression results suggest that T11 and M23 landraces are the most NaCl stress tolerant landraces and could be used to enhance the gene pool in wheat breeding programs.