SummaryEmploying genetic transformation using an Atcys-3A cDNA construct expressing the cytosolic O -acetylserine(thiol)lyase (OASTL), we obtained two Arabidopsis lines with different capabilities for supplying cysteine under metal stress conditions. Lines 1-2 and 10-10, grown under standard conditions, showed similar levels of cysteine and glutathione (GSH) to those of the wild-type. However, in the presence of cadmium, line 10-10 showed significantly higher levels. The increased thiol content allowed line 10-10 to survive under severe heavy metal stress conditions (up to 400 µ M of cadmium in the growth medium), and resulted in an accumulation of cadmium in the leaves to a level similar to that of metal hyperaccumulator plants. Investigation of the epidermal leaf surface clearly showed that most of the cadmium had accumulated in the trichomes. Furthermore, line 10-10 was able to accumulate more cadmium in its trichomes than the wild-type, whereas line 1-2 showed a reduced capacity for cadmium accumulation. Our results suggest that an increased rate of cysteine biosynthesis is responsible for the enhanced cadmium tolerance and accumulation in trichome leaves. Thus, molecular engineering of the cysteine biosynthesis pathway, together with modification of the number of leaf trichomes, may have considerable potential in increasing heavy metal accumulation for phytoremediation purposes.

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In science applied to cultural heritage, the study of the manufacturing procedures of ancient metal artifacts is of particular relevance. In fact, metal manufacturing is correlated with the development of civilization. The aim of this work is to reconstruct, by means of experimental archeology, the ancient soldering and welding processes, in order to identify them in archeological samples using a portable micro X‐ray fluorescence (micro‐XRF) system. This portable and nondestructive technique provides a useful method for characterizing the manufacturing of ancient gold jewelry. Various gold alloys were produced with different Ag and Cu content to simulate real cases. Besides, on the basis of archeometallurgy techniques, replicas of decorations were fabricated following the ancient recipes such as those described in Naturalis Historia and Leiden Papyrus X. The content of Au, Ag, and Cu within the soldering or welding areas was quantified with the micro‐XRF technique. The methodology described in this work was applied to the particular case of alloys with high gold concentrations, such as Tartessic jewelry (700–500 BC), to identify the different welding and soldering techniques. Copyright © 2013 John Wiley & Sons, Ltd.