Agro-Physiological and DNA Methylation Responses to Salinity Stress in Wheat ( L.), Host, and Their Introgressed Lines.

Bottlenecks, including limited genetic variation and the ongoing loss of genetic diversity, have hindered the development of modern wheat cultivars., making it crucial to use genetic diversity from wild relatives to improve wheat's adaptation to abiotic stress, such as salinity. This study assessed the phenotypic and epigenetic variation of introgressed wheat lines (BCF) derived from hybridizing two wheat cultivars with (AC). This study assessed the phenotypic and epigenetic variation of 156 introgressed wheat lines (BCF) derived from hybridization between wheat cultivars "Chinese Spring" (CS) and "Roshan" (R) and (AC). These lines and their recurrent parents (total of 158) were evaluated under normal and saline field conditions for the agronomic traits and stress tolerance indices. The data were used to select the most tolerant and most sensitive lines. Then, the selected BCF lines and their parents (AC, CS, and R) were subjected to physiological, DNA cytosine methylation, and expression analysis of , , and genes under control and salt stress conditions. Agro-physiological, epigenetic, and gene expression analyses showed the significant effects of salt stress and genetic background, as well as the differential response of the BCF lines to salt stress. The variations in leaf and root K, Na, and K/Na ratios, and leaf Chla, Chlb, Car, and MDA levels, unlike DPPH radical scavenging levels, between salt-tolerant and salt-sensitive BCF lines under saline conditions indicated a substantial distinction in salinity tolerance responses. RT-qPCR indicated higher expression levels of and genes in the leaf and root tissues of tolerant lines than those of sensitive lines. Global leaf and root DNA methylation analysis revealed the significant effects of salinity on the methylation modifications and confirmed the successful introgression of the salt-tolerance epigenome from into wheat. Exploiting the genetic diversity of wild wheat relatives is a crucial goal for increasing genetic and epigenetic variation to enhance plant adaptation to salt stress.