Employment of Wheat-Rye 1RS Translocations in Improvement of Abiotic Stress Tolerance

Wheat-rye translocations have been successfully utilized in wheat breeding thanks to beneficial genes on rye chromosomes that confer resistance to biotic and abiotic stresses. However, huge and repetitive genome of rye has hindered discovering novel useful genes in rye and wheat-rye translocations. In this study, we investigated the transcripts of 1BL.1RS under drought or cold treatment, using near-isolines that lack or possess 1RS. First, cDNA-AFLP analysis was performed using root RNA from PEG-treated near-isolines. TDF (transcript-derived fragments) specific to 1BL.1RS were sequenced and categorized according to their biological functions. Chromosomal localization was conducted by BLASTn search against Wheat URGI CSS database. The expression of each TDF was verified via RT-PCR analysis. Furthermore, PCR markers specific to 1RS were developed, which could be utilized in wheat breeding. Secondly, survival rate of the near-isolines under freezing temperature with or without pre-acclimation was investigated. Non-translocation did not exhibit significant difference depending on the pre-acclimation, but 1BL.1RS showed much higher survival rate when the acclimation was preceded. Measuring abiotic stress related factors, MDA (malondialdehyde), proline and soluble sugar revealed that 1BL.1RS performed superior under freezing stress. Particularly, proline was highly accumulated during acclimation in 1BL.1RS. RNA-seq on the control and the acclimated plants unravelled thousands of differentially expressed genes. Further studies on these genes will help to understand the mechanism of freezing tolerance in 1BL.1RS. Acknowledgement: This work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ01103501)” Rural Development Administration. Republic of Korea.