Cucumber (Cucumis sativus, Cucurbitaceae) is a widely used dicot model for silicon accumulation. However, little is known about the molecular mechanism of its silicon uptake. Sun et al. isolate a silicon efflux transporter gene, CsLsi2, from cucumber.
They demonstrate that CsLsi2 has efflux transport activity for silicon and that it is mainly localized on the plasma membrane of endodermal cells in roots. In combination with their previous work in CsLsi1, a silicon influx transporter gene from cucumber, Sun et al. propose a model for silicon uptake in cucumber roots.