Bacterial Quorum-Sensing Signal Molecule, N-Acyl-L-Homoserine Lactones Induce Intracellular Ca²⁺ Elevation In Arabidoposis Root Cells

The change of cytosolic calcium concentration induced by a bacterial quorum sensing signal, N-acyl-L-homoserine lactones and the origin of calcium in Arabidopsis root cells are measured. The changes of [Ca²⁺]cyt were studied by aequorin luminometers, and the origin of calcium using EGTA, verapamil, LaCl3 and LiCl. The addition of AHLs to root cells induced an instant increase in [Ca²⁺]cyt. The elevation of [Ca²⁺]cyt induced by treating with AHLs was suppressed after pretreated with EGTA, verapamil and LaCl3. Patch-clamp analysis revealed a Ca²⁺ influx in Arabidopsis root cells after incubation with AHLs. At the same time, the result of root growth showed that AHLs may obviously induce the lengthen of Arabidopsis root. As pretreated with EGTA, verapamil or LaCl3, lengthen of the root induced by AHLs was restrained. Taken together, the present results suggest that Arabidopsis respond to bacterial quorum sensing signal with the [Ca²⁺]cyt elevation and the increase of cytosolic calcium was mainly due to the influx of extracellular calcium. AHLs induced intracellular calcium signal in Arabidopsis root elongation related.