MsTIFY10a gene from alfalfa negatively regulates drought and salt tolerance in transgenic tobacco

The JAZ protein family acts as a key negative regulator in the jasmonic acid signaling pathway, interacting with transcription factors and playing essential roles in plant growth, development, and abiotic stress responses. However, the specific function of JAZ transcription factors in mediating salt and drought stress tolerance in alfalfa (Medicago sativa) remains unclear. In this study, we cloned MsTIFY10a, a JAZ gene from alfalfa, and found that its expression was downregulated under salt and drought stresses. Heterologous expression of MsTIFY10a in tobacco significantly reduced tolerance to both drought and salt stresses in seedlings and mature plants. Physiological analysis revealed that MsTIFY10a overexpression suppressed the antioxidant system, including superoxide dismutase (SOD) and peroxidase (POD), compromised photosynthetic capacity, and exacerbated membrane damage, collectively leading to reduced stress tolerance. Moreover, under drought or salt treatment, MsTIFY10a overexpression downregulated the expression of several reactive oxygen species (ROS)-related and stress-responsive genes. In summary, MsTIFY10a may functions as a negative regulator in abiotic stress responses, providing a basis for further investigation into its mechanistic roles in alfalfa.