Small heat shock proteins （Small heat shock proteins， sHSPs） are a class of stress-induced proteins widely present in plants， play crucial roles in plant growth， development， and response to drought and salt stresses. To investigate the function of the MsHSP18.2 gene in Medicago sativa， bioinformatics tools were employed to predict and analyze its theoretical properties， structure， and function. Plants were treated with methyl jasmonate （MeJA）， salicylic acid （SA）， abscisic acid （ABA）， indole-3-acetic acid （IAA）， gibberellin （GA）， and cytokinin （6-BA）， as well as subjected to drought and salt stress. Gene expression levels were analyzed by qRT-PCR at 0， 0.5， 1， 3， 6， 9， and 12 hours post-treatment. Transcriptional autoactivation was examined by using a yeast expression system. The stress resistance function was verified using a heterologous yeast system. The results showed that this protein has a molecular weight of 18.18 KDa and a theoretical isoelectric point of 5.55， exhibiting relatively high instability （instability index： 54.67）. Its secondary structure was predominantly composed of random coils. Expression analysis demonstrated that MsHSP18.2 was upregulated under drought and salt stress treatments and displayed differential responses to various plant hormones. Yeast autoactivation assays confirmed its autoactivation activity. Heterologous overexpression of MsHSP18.2 gene significantly enhanced the salt tolerance （NaCl） and osmotic stress （PEG） tolerance of yeast cells.

MsHSP18.2  /  Medicago sativa  /  Bioinformatics analysis  /  Expression analysis  /  Self-activation detection