Principal mechanism of tolerance to abiotic stresses in Cynara cardunculus L.

Abiotic stresses, that characterize many world marginal areas, are increased by climate change. The plant response to these stresses consists of different processes to alleviate both cellular hyperosmolarity and ion disequilibrium or to synthesize antioxidant compounds. Cardoon (Cynara cardunculus L.) is a perennial crop of the Asteraceae family, native to the Mediterranean region, with a high production of biomass and grain, available for green chemistry, and able to grow in stressful environment. The aim of this work was to investigate different cardoon response mechanisms to abiotic stresses. Following this purpose, we evaluated the ability of cardoon seeds to germinate under salt stress condition and on the sprouts obtained we measured the total phenols content (TPC) and antioxidant activity (AA). In addition, the growth of cardoon seedlings under heavy metals (arsenic and cadmium) stress conditions was monitored. Moreover, based on library of cDNA previously constructed from seedlings growth in similar stress condition, the gene Phytochelatin Synthase (PS), associated with abiotic stress tolerance, was isolated. Furthermore, Natural Resistance of Macrophage (NRAMP3), Heavy metal ATPase (HMA), Inorganic Phosphate Transport (PHT), Zinc and Iron Protein (ZIP) genes associated with heavy metal stress were isolated and the levels of gene expression were measured. The results showed the ability of C. cardunculus to tolerate salt and heavy metals stresses, thanks to different defense mechanisms against abiotic stress implemented by cardoon plants. Then, this species can be considered as a promising future crop for green chemistry in marginal lands.