CDC48 is a conserved chaperone protein belonging to the AAA+ ATPase family (ATPase associated with various activities). This protein uses binding and hydrolysis of ATP to generate forces to affect the transformation of polypeptide substrate in numerous cellular processes. Studies on mammalian CDC48 orthologue revealed that it recognizes ubiquitylated polypeptides, directly or via partners, leading to substrate degradation or recycling. In plants, functions of CDC48 is less understood. The aim of my thesis, is to decipher the role of CDC48 in plant defense response context. First, I have to characterize NtCDC48 in tobacco (Nicotiana tabacum) suspension cells elicited by cryptogein, an elicitin produced by the oomycete Phytophthora cryptogea. Secondly, I have to confirm interactions with different partners previously established by the team, after that, I have to study involvement of those partners in plant immunity. As expected, those partners contribute in diverse cellular processes. Currently, I focus my attention on the interaction between NtCDC48 and the cytosolic ascorbate peroxidase (cAPX), a protein involved on the detoxification of reactive oxygen species. Our first results indicate that CDC48 protein and mRNA accumulate during cryptogein treatment, highlighting that the chaperone protein is involved in immune response. Then, thanks to a cell line overexpressing our protein of interest, we propose that NtCDC48 might have a function in the elicitor-triggered cell death.