Functional Characterization of Arabidopsis thaliana Cyclic Nucleotide-Gated Ion

Abstract

Cyclic nucleotide-gated ion channels (CNGCs) are a recently identified group of plant ion channels. There are 20 members in the family, and their function in plants is only starting to be understood. In this study, seven of these ion channels were analyzed for their importance in both basal and R-gene mediated pathogen defense signaling in Arabidopsis thaliana. In order to assess functional characteristics of these channels, A. thaliana knockout lines of the seven ATCNGCs (ATCNGC 3, 6 , 11, 12, 13, 19, and 20) were obtained. Bacterial growth curve assays and ion leakage experiments were used to study the role of the studied ATCNGCs in terms of pathogen susceptibility and the hypersensitive response. Plants deficient for any of these channels exhibited increased susceptibility to avirulent pathogens, but showed wild type susceptibility to virulent pathogen infection. From these results, it appears that ATCNGC 3, 6 , 11, 12, 13, 19, and 20 play a critical role in the R gene mediated plant pathogen defense signaling pathway.