Proline is an important component of salt-stress responses of plants. In this study the role of proline as part of salt-stress signalling in the desert plant Pancratium maritimum L. was examined. The data showed that salt-stress brought about a reduction of the growth and protein content, particularly at 300 mM NaCl, that was significantly increased by exogenous proline. In the leaves, salt-stress up-regulated ubiquitin, a small protein targeting damaged proteins for degradation via the proteasome, up to 5-fold as detected by western blotting. This change was also affected by proline even in non-stressed leaves. However, salt-stress resulted in a decrease in the amount of ubiquitin-conjugates, particularly in the roots, and this effect was reversed by exogenous proline. Severe salt-stress resulted in an inhibition of the antioxidative enzymes catalase and peroxidase as revealed by spectrophotometric assays and activity gels, but the activity of these enzymes was also maintained significantly higher in the presence of proline. Salt-stress also up-regulated several dehydrin proteins, analysed by western blotting, even in non-stressed plants. It is concluded that proline improves the salt-tolerance of Pancratium maritimum L. by protecting the protein turnover machinery against stress-damage and up-regulating stress protective proteins.

New series of benzothiazole-2-thiol (2-MBT) derivatives were synthesized and Structures of the synthesized compounds were established on the basis of 1 H NMR in DMSO-d 6 and FTIR in KBr spectral data. Acetylene derivatives were prepared by the reaction of 2-MBT with 3-bromo propyne in base medium (Nucleophilic Substitution reaction-SN2) that gives (2-(prop-2-yn-1-ylthio) benzo[d]thiazole) 85% yield, these derivative was oxidized by using mixture of potassium dichromate and concentrated sulphuric acid in presence of glacial acetic acid as a solvent to give (2-(prop-2-yn-1-ylsulfonyl) benzo[d]thiazole) 72% yield.Mannich reactions were done by using (2-(prop-2-yn-1-ylsulfonyl) benzo[d]thiazole), Para formaldehyde and various secondary amines in the presence of cuprous chloride as a catalyst and dioxane as a solvent to give different derivatives 44-68% yield, and we think these compounds may have biological activity.

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