Abscisic Acid, Stress, and Ripening (ASR1) Gene as a Functional Marker for Salt Tolerance in Durum Wheat.

In semiarid Mediterranean agroecosystems, drought and salinity are the main abiotic stresses hampering wheat productivity and yield instability. Abscisic acid, stress, and ripening (ASR) are small plant proteins and play important roles in different biological processes. In the present study, the ASR1 gene was isolated and characterized for the first time from durum wheat ( L. subsp. ). ASR1 is a small gene, about 684 bp long, located on chromosome 4AL, encoding a protein of 136 amino acid residues consisting of a histidine-rich N terminus and C-terminal conserved ABA-WDS domain (Pfam PF02496). Our results showed that ASR1 protein could function as a chaperone-like protein and improve the viability of under heat and cold stress and increase the tolerance under salt and osmotic stress. Transcript expression patterns of ASR1 revealed that ASRs play important roles in abiotic stress responses in diverse organs. Indeed, ASR1 was upregulated in leaves by different developmental (ABA) and environmental signals (PEG, salt). In . Mahmoudi (salt-tolerant Tunisian durum landraces) roots, ASR1 was upregulated by salt stress, while it was downregulated in cv. Azizi (salt-sensitive Tunisian durum landraces), supporting the implication of this gene in the salt tolerance mechanism. Taken together and after validation in the plant system, the ASR1 gene may provide a potential functional marker for marker-assisted selection in a durum wheat breeding program for salt tolerance.