Light-activated channelrhodopsins: a revolutionary toolkit for the remote control of plant signalling.

Channelrhodopsins (CHRs), originating within algae and protists, are membrane-spanning ion channel proteins that are directly activated and/or deactivated by specific wavelengths of light. Since 2005, CHRs have been deployed as genetically encoded optogenetic tools to rapidly advance understanding of neuronal networks. CHRs provide the opportunity to finely tune ion transport across membranes and regulate membrane potential.

Date palm diverts organic solutes for root osmotic adjustment and protects leaves from oxidative damage in early drought acclimation.

Date palm (Phoenix dactylifera L.) is an important crop in arid regions that is well-adapted to desert ecosystems. To understand the remarkable ability to grow and yield in water-limited environments, experiments with water-withholding for up to four weeks were conducted.

Guard cells count the number of unitary cytosolic Ca signals to regulate stomatal dynamics.

Transient stimulus-specific increases in the cytosolic Ca concentration ("calcium signatures") of guard cells have been proposed to regulate the opening and closure of stomatal pores on plant leaves. However, the mechanism by which these Ca signatures are generated and translated into stomatal movement is still largely unresolved. We used a light-gated, Ca-permeable variant of ChannelRhodopsin 2 (ChR2-XXM2.

Arabidopsis HAK5 under low K availability operates as PMF powered high-affinity K transporter.

Plants can survive in soils of low micromolar potassium (K) concentrations. Root K intake is accomplished by the K channel AKT1 and KUP/HAK/KT type high-affinity K transporters. Arabidopsis HAK5 mutants impaired in low K acquisition have been identified already more than two decades ago, the molecular mechanism, however, is still a matter of debate also because of lack of direct measurements of HAK5-mediated K currents.