Heat shock proteins (HSPs) are generally considered as important molecular chaperones; they are known to perform critical functions in plant development and abiotic stress response processes. | Turkish Journal of Biology Turk J Biol (2018) 42: 12-22 © TÜBİTAK doi: Research Article Overexpression of the alfalfa DnaJ-like protein (MsDJLP) gene enhances tolerance to chilling and heat stresses in transgenic tobacco plants 1, 1, 1 1 2 Ki-Won LEE *, Md. Atikur RAHMAN *, Ki-Yong KIM , Gi Jun CHOI , Joon-Yung CHA , 2 3 4 1, Mi Sun CHEONG , Abdullah Mohammad SHOHAEL , Chris JONES , Sang-Hoon LEE ** 1 Molecular Breeding Laboratory, Grassland and Forages Division, National Institute of Animal Science, Rural Development Administration, Cheonan, Republic of Korea 2 Division of Applied Life Science (BK21Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Republic of Korea 3 Department of Biotechnology & Genetic Engineering, Jahangirnagar University, Dhaka, Bangladesh 4 Feed and Forage Biosciences, International Livestock Research Institute, Addis Ababa, Ethiopia Received: Accepted/Published Online: Final Version: Abstract: Heat shock proteins (HSPs) are generally considered as important molecular chaperones; they are known to perform critical functions in plant development and abiotic stress response processes. In this study, we examined the role of a HSP, the Medicago sativa DnaJ-like protein (MsDJLP), in alfalfa and its potential application for the development of abiotic stress tolerance in plants. We found that expression of the MsDJLP gene was induced by chilling (4 °C) and heat (42 °C), but not by cadmium (500 µM) or arsenic (500 µM) stresses. We then cloned the MsDJLP gene downstream of the strong constitutive CaMV 35S promoter and transformed it into tobacco plants. Ectopic expression of MsDJLP conferred enhanced tolerance to both chilling and heat stresses in transgenic tobacco plants. Under chilling stress, the transgenic tobacco plants showed lower H2O2 accumulation and electrolyte leakage (EL) activity,