Abscisic Acid, Stress, and Ripening (TtASR1) Gene as a Functional Marker for Salt Tolerance in Durum Wheat

Abstract

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 TtASR1 gene was isolated and characterized for the first time from durum wheat (Tritucum turgidum L. subsp. durum). TtASR1 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 TtASR1 protein could function as a chaperone-like protein and improve the viability of E. coli under heat and cold stress and increase the Saccharomyces cerevisiae tolerance under salt and osmotic stress. Transcript expression patterns of TtASR1 revealed that ASRs play important roles in abiotic stress responses in diverse organs. Indeed, TtASR1 was upregulated in leaves by different developmental (ABA) and environmental signals (PEG, salt). In cv. Mahmoudi (salt-tolerant Tunisian durum landraces) roots, TtASR1 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 TtASR1 gene may provide a potential functional marker for marker-assisted selection in a durum wheat breeding program for salt tolerance.

Functional Markers for Precision Plant Breeding

“…Pandey et al [ 209 ] developed SNP-based FMs for the TaAQP gene encoding drought tolerance, which was validated in wheat varieties. Similarly, an FM for the TtASR1 gene encoding salt tolerance in wheat has been developed, which should be helpful to screen wheat germplasm for salt tolerance [ 211 ].…”

Dissecting the Molecular Function of Triticum aestivum STI Family Members Under Heat Stress

“…Arabidopsis plants were grown on half strength Murashige and Skoog (MS) media. For the stress treatment of wheat, 10-day-old seedlings were subjected to different abiotic stresses such as heat (42 • C for 2 h), cold (4 • C for 24 h), salt (200 mM for 24 h), and drought (200 mM mannitol for 24 h) (Peng et al, 2009;Chauhan et al, 2011;Amoah et al, 2019;Hamdi et al, 2020). Ten-day-old seedlings of genotype PBW343 and C306 were subjected to different temperatures ranging from 25 • C to 45 • C. After the stress treatment, seedlings of control and treated plants were frozen in liquid nitrogen and stored at −80 • C until RNA isolation.…”

Structural and Functional Characterization of the ABA-Water Deficit Stress Domain from Wheat and Barley: An Intrinsically Disordered Domain behind the Versatile Functions of the Plant Abscissic Acid, Stress and Ripening Protein Family

“…In 2014, the group of Gonzalez supported the view that the ASR family should be classified as an important group of ABA-Water Deficit Stress Domain (ABA-WDS) proteins with distinct and unique functions and roles [ 3 ]. The conservation of the ABA-WDS domain (Pfam 02496 and IPR063494) in members of the ASR family (as illustrated in the multiple sequence alignment of ASR proteins we previously reported [ 9 ]) argues for a functional significance. Noteworthy, in some cases, as for instance in the ASR protein from rice (Os ASR1), the domain represents more than 65% of the full-length protein [ 27 ].…”

“…In the same context, tomato ASR1 can act as a transcription factor because of its ability to bind DNA in a sequence-specific and Zn-dependent manner [ 7 , 8 ]. On the other hand, ASRs have been shown to have chaperone-like activity for direct plant protection under stress conditions as in the case of ASR from wheat, plantain and tomato [ 3 , 7 , 9 ]. ASR proteins have been reported to be implicated in plant development, senescence, and fruit ripening and to play crucial roles in abiotic stress tolerance in most plants, as observed for Oryza sativa ASR1 (OsASR1) [ 10 ], Zea mays ASR1 (ZmASR1) [ 11 ], and Triticum aestivum (TaASR1) [ 12 ].…”

“…In order to fill in this gap in knowledge, and with the aim of ascertaining whether the ABA-WDS domain is functional on its own, we herein report the identification, structural and functional characterization of two ABA-WDS domains, TtABA-WDS and HvABA-WDS, isolated respectively, from salt-stressed durum wheat and barley leaves. The rationale for focusing on durum wheat and barley resides in pursuing and extending our previous studies that reported the characterization of two ASR proteins from these two cereals [ 17 ] and that showed the role of the ASR family in salt and drought tolerance in durum wheat [ 9 ].…”