Proteomic analysis of salt-responsive proteins in the leaves of two contrasting Tunisian barley landraces

Salinity is a brutal environmental factor that severely affects barley growth and development. In this context, local landraces, commonly cultivated under stressful conditions, could represent important reservoirs of valuable traits in barley breeding programs. Therefore, understanding salt-tolerance mechanisms in such genotypes is of great interest. Here, based on a 2D-PAGE comparative proteomic study, salt-induced proteome changes were explored in the seedling leaves of two contrasting Tunisian landraces, namely Boulifa (tolerant) and Testour (sensitive). The analysis showed that 11 salt-responsive proteins were differentially accumulated in both accessions under salt stress and 43 were genotype-specific (18 in Boulifa and 25 in Testour). Using mass spectrometry identification and annotation, 11 function categories revealed being involved in salt-stress response, specifically the defense/cell wall related metabolism. In fact, a chitinase, was up-regulated in the tolerant accession and down-regulated in the sensitive one in addition to a ricin B-like lectin R40G3 as well as a predicted BSP that were up-regulated in the tolerant one. Then, two other chitinases, PR10, glucan endo-1.3-β-glucosidase, were down-regulated in Testour, while still unchanged in the tolerant accession Boulifa. In the latter, signaling, redox/polyamine catabolism and the energy metabolism were found as part of the biochemical pathways underlying salt-tolerance. These results suggest that Boulifa may alleviate salt stress by activation of specific defense responses, and adjustment of both redox/polyamine catabolism and energy metabolism processes. Our findings represent a basis that would assist selection of candidates as markers in improving barley salt tolerance and elite genotypes creation.

     

Synthesis and biodistribution of [99mTc]-N-[4-nitro-3-trifluoromethyl-phenyl] cyclopentadienyltricarbonyltechnetium carboxamide, a nonsteroidal antiandrogen flutamide derivative

In our efforts to develop a novel class of SPECT imaging agents based on nonsteroidal androgen receptor (AR) antagonists, we have synthesized N-cyclopentadienyltricarbonyltechnetium-N-[4-nitro-3-trifluoromethyl-phenyl] carboxamide (NF(99m)Tc), an analog of the AR antagonist ligand flutamide. NF(99m)Tc was obtained in 82% yield from the reaction of N-[4-nitro-3-trifluoromethyl-phenyl]-ferrocenecarboxamide (NFFe) with fac-[(99m)Tc(H(2)O)(3)(CO)(3)](+) in DMF-water at pH 1 and at 150 °C for 1 h. The corresponding Re analog was also prepared. In vitro assays demonstrated high stability of NF(99m)Tc under physiological conditions, buffer and blood. The tissue biodistribution in mature male Wistar rats showed a significant selective uptake by prostate but this uptake was not blocked by an excess of testosterone acetate. A higher uptake by lung tissues was observed.