A bi-kinase module sensitizes and potentiates plant immune signaling.

Systemic signaling is an essential hallmark of multicellular life. Pathogen encounter occurs locally but triggers organ-scale and organismic immune responses. In plants, elicitor perception provokes systemically expanding Ca and HO signals conferring immunity.

A salt stress-activated GSO1-SOS2-SOS1 module protects the Arabidopsis root stem cell niche by enhancing sodium ion extrusion.

Soil salinity impairs plant growth reducing crop productivity. Toxic accumulation of sodium ions is counteracted by the Salt Overly Sensitive (SOS) pathway for Na extrusion, comprising the Na transporter SOS1, the kinase SOS2, and SOS3 as one of several Calcineurin-B-like (CBL) Ca sensors. Here, we report that the receptor-like kinase GSO1/SGN3 activates SOS2, independently of SOS3 binding, by physical interaction and phosphorylation at Thr16.

Phosphatidic acid-regulated SOS2 controls sodium and potassium homeostasis in Arabidopsis under salt stress.

The maintenance of sodium/potassium (Na /K ) homeostasis in plant cells is essential for salt tolerance. Plants export excess Na out of cells mainly through the Salt Overly Sensitive (SOS) pathway, activated by a calcium signal; however, it is unknown whether other signals regulate the SOS pathway and how K uptake is regulated under salt stress. Phosphatidic acid (PA) is emerging as a lipid signaling molecule that modulates cellular processes in development and the response to stimuli.

A Ca-sensor switch for tolerance to elevated salt stress in Arabidopsis.

Excessive Na in soils inhibits plant growth. Here, we report that Na stress triggers primary calcium signals specifically in a cell group within the root differentiation zone, thus forming a "sodium-sensing niche" in Arabidopsis. The amplitude of this primary calcium signal and the speed of the resulting Ca wave dose-dependently increase with rising Na concentrations, thus providing quantitative information about the stress intensity encountered.

The potassium channel GhAKT2bD is regulated by CBL-CIPK calcium signalling complexes and facilitates K allocation in cotton.

Efficient allocation of the essential nutrient potassium (K ) is a central determinant of plant ion homeostasis and involves AKT2 K channels. Here, we characterize four AKT2 K channels from cotton and report that xylem and phloem expressed GhAKT2bD facilitates K allocation and that AKT2-silencing impairs plant growth and development. We uncover kinase activity-dependent activation of GhAKT2bD-mediated K uptake by AtCBL4-GhCIPK1 calcium signalling complexes in HEK293T cells.