Expression analysis of some transcription-factor genes related to endoplazmik reticulum stress signaling pathway in alfalfa (Medicago sativa L.)

Perception of biotic and abiotic stress conditions in plants and to provide tolerance carries a crucial importance in prevention of huge yield losses. Identification of genes playing a role in stress tolerance has a great importance in elucidation of stress pathways. In this study, the water potentials of the leaves of the plants grown under stress factors (DTT and PEG) were measured and the critical time intervals for the plant were obtained as physiological preliminary findings. Expression analysis of bZIP60 and bZIP28 genes involved at ER stress pathways were evaluated by RT-PCR assay at determined intervals of time, (in alfalfa cultivar Nimet) under the artificial ER stress implemented by DTT and drought stress (PEG). According to the results, it was determined that DTT reduced the function of these two genes involved in ER stress pathways. It was determined that the most critical time for plants in drought (PEG) tolerance was 8 hours after treatment, in which the expression of bZIP60 in leaves was increased more than other applications (about 42 times). Furthermore, according to the findings, of the two studied gene regions bZIP60 have a more active role in the stress pathways than bZIP28; and the leaf tissues were more affected than the root tissues under the stress conditions. This study is the first research on alfalfa expression of genes involved in ER stress mechanisms and it is thought that it will contribute to the future studies on ER stress mechanism. Key words: ER stress, Transcription factors expression, Alfalfa stress mechanism