Biotic and Abiotic Stresses Activate Different Ca(2+) Permeable Channels in Arabidopsis

To survive, plants must respond rapidly and effectively to various stress factors, including biotic and abiotic stresses. Salinity stress triggers the increase of cytosolic free Ca(2+) concentration ([Ca(2+)](i)) via Ca(2+) influx across the plasma membrane, as well as bacterial flg22 and plant endogenous peptide Pep1. However, the interaction between abiotic stress-induced [Ca(2+)](i) increases and biotic stress-induced [Ca(2+)](i) increases is still not clear. Employing an aequorin-based Ca(2+) imaging assay, in this work, we investigated the [Ca(2+)](i) changes in response to flg22, Pep1, and NaCl treatments in Arabidopsis thaliana. We observed an additive effect on the [Ca(2+)](i) increase which induced by flg22, Pep1, and NaCl. Our results indicate that biotic and abiotic stresses may activate different Ca(2+) permeable channels. Further, calcium signal induced by biotic and abiotic stresses was independent in terms of spatial and temporal patterning.