SSA4 Mediates Cd Tolerance via Activation of the Cis Element of VHS1 in Yeast and Enhances Cd Tolerance in Chinese Cabbage

Identifying key genes involved in Cadmium (Cd) response pathways in plants and developing low-Cd-accumulating cultivars may be the most effective and eco-friendly strategy to tackle the problem of Cd pollution in crops. In our previous study, <i>Stressseventy subfamily A 4</i> (<i>SSA4</i>) was identified to be associated with Cd tolerance in yeast. Here, we investigated the mechanism of <i>SSA4</i> in regulating Cd tolerance in yeast. ScSSA4 binds to POre Membrane 34 (POM34), a key component of nuclear pore complex (NPC), and translocates from the cytoplasm to the nucleus, where it regulates the expression of its downstream gene, <i>Viable in a Hal3 Sit4 background 1</i> (<i>VHS1</i>), resulting in reduced Cd accumulation in yeast cells. Additionally, we identified a Chinese cabbage <i>SSA4</i> gene, <i>BrSSA4c</i>, which could enhance the Cd tolerance in Chinese cabbage. This study offers new insights into the regulatory mechanisms of Cd tolerance in yeast, a model organism, and paves the way for the genetic enhancement of Cd tolerance in Chinese cabbage.