Lithium alters phosphoinosite signaling in rice roots under anoxia

The presence of lithium increased the level of η-aminobutyric acid (Gaba) and inositol 1,4,5-triphosphate (IP3) in rice roots during 3 h of anoxia. The IP3 increase induced by Li+ was abolished by the phospholipase C inhibitor neomycin. The effect of Li+ on Gaba accumulation was inhibited by the presence of the calmodulin antagonist trifluoperazine. These findings are consistent with an inhibitory effect of Li+ on inositol monophosphatase, which increased the IP3 level. This is further confirmation of the role of IP3 in the anaerobic signal transduction pathway.