title: Crossroads of stress responses, development and flowering regulation--the multiple roles of Cyclic Nucleotide Gated Ion Channel 2.
abstract: The Arabidopsis autoimmune mutant, defense-no death 1 (dnd1) is a null mutant of CYCLIC NUCLEOTIDE-GATED ION CHANNEL2 (AtCNGC2). dnd1 exhibits constitutive pathogen resistance responses including higher levels of endogenous salicylic acid (SA), which is an important signaling molecule for pathogen defense responses. Recently we have reported that dnd1 exhibits a significantly delayed flowering phenotype, indicating the involvement of AtCNGC2 in flowering transition. However, since SA has been known to influence flowering timing as a positive regulator, the delayed flowering phenotype in dnd1 was unexpected. In this study, we have asked whether SA is involved in the dnd1-mediated delayed flowering phenotype. In addition, in order to gain insight into the involvement of SA and CNGCs in flowering transition, we analyzed the flowering transition of cpr22, another CNGC mutant with a similar autoimmune phenotype as dnd1 (including high SA accumulation), and null mutants of several other CNGCs. Our data suggest that dnd1 does not require SA or SA signaling for its delayed flowering phenotype, while SA was responsible for the early flowering phenotype of cpr22. None of the other CNGC mutants besides AtCNGC4 (1) displayed an alteration in flowering transition. This indicates that AtCNGC2 and AtCNGC4 have a unique role controlling flowering timing and this function is independent from its role in pathogen defense.
authors.affiliation: a Department of Cell and Systems Biology ; University of Toronto ; Toronto , Canada.
authors.forename: Alex
authors.initials: A
authors.lastname: Fortuna
authors.forename: Jihyun
authors.initials: J
authors.lastname: Lee
authors.forename: Huoi
authors.initials: H
authors.lastname: Ung
authors.forename: Kimberley
authors.initials: K
authors.lastname: Chin
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Moeder
authors.forename: Keiko
authors.initials: K
authors.lastname: Yoshioka
mesh_terms: D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics* / Q000378:metabolism; D060467:Disease Resistance; D035264:Flowers / Q000254:growth & development* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases; D010937:Plant Growth Regulators / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: C518230:ATCNGC4 protein, Arabidopsis; D029681:Arabidopsis Proteins; C518228:CNGC2 protein, Arabidopsis; D054815:Cyclic Nucleotide-Gated Cation Channels; D010937:Plant Growth Regulators; D020156:Salicylic Acid
keywords: CNGC; CNGC, cyclic nucleotide-gated ion channel; SA, salicylic acid; cpr22; cyclic nucleotide-gated ion channel; defense-no-death 1; dnd1; flowering; salicylic acid