Genome-Wide Identification and Characterization of the Wheat Remorin ( REM) Family during Cold Acclimation

Remorins (REMs) are plant-specific proteins that play an essential role in plant-microbe interactions. However, their roles in vernalization and abiotic stress responses remain speculative. Most remorins have a variable proline-rich N-half and a more conserved C-half that is predicted to form coils. A search of the wheat (Triticum aestivum L.) database revealed the existence of 20 different REM genes, which we classified into six groups on the basis of whether they shared a common phylogenetic and structural origin. Analysis of the physical genomic distributions demonstrated that REM genes are dispersed in the wheat genome and have one to seven introns. Promoter analysis of TaREM genes revealed the presence of putative cis-elements related to diverse functions like development, hormonal regulation, and biotic and abiotic stress responsiveness. Expression levels of TaREM genes were measured in plants grown under field and controlled conditions and in response to hormone treatment. Our analyses revealed that 12 members of the REM family are regulated during cold acclimation in wheat in four different tissues (roots, crowns, stems, and leaves), with the highest expression in roots. Differential gene expression was found between wheat cultivars with contrasting degrees of cold tolerance, suggesting the implication of TaREM genes in cold response and tolerance. Additionally, eight genes were induced in response to abscisic acid and methyl jasmonate treatment. This genome-wide analysis of TaREM genes provides valuable resources for functional analysis aimed at understanding their role in stress adaptation.