| Abstract Detail
Plant-Pathogen Interactions Baxter, Joyce [1], Moeder, Wolfgang [1], Wang, Maggie [1], Urquhart, William [1], Christendat, Dinesh [1], Yoshioka, Keiko [2]. Identification of a functionally essential amino acid for the cyclic nucleotide gated ion channel ATCNGC11/12. To investigate the resistance signaling pathways activated by pathogen infection, we previously identified the Arabidopsis mutant constitutive expresser of PR genes22 (cpr22) (Yoshioka et al., 2001). The cpr22 mutation was identified as a 3-kb deletion that fuses two cyclic nucleotide-gated ion channel (ATCNGC)-encoding genes, ATCNGC11 and ATCNGC12, to generate a novel chimeric gene, ATCNGC11/12 (Yoshioka et al., 2006). Genetic, molecular, and complementation analyses suggest that ATCNGC11/12, as well as ATCNGC11 and ATCNGC12, form functional cAMP-activated CNGCs and that the phenotype conferred by cpr22 is attributable to the expression of ATCNGC11/12. Recently, a genetic screen for mutants that suppresses cpr22-conferred phenotypes identified one intragenic mutation of cpr22 (suppressor #73). This mutation locates within the cyclic nucleotide binding domain in ATCNGC11/12. The mutant suppressor #73 is morphologically identical to wild type and lost spontaneous cell death formation and enhanced pathogen resistance. Transient expression in Nicotiana benthamiana confirmed that this mutation is responsible for suppression of spontaneous cell death formation by ATCNGC11/12. Furthermore, heterologous expression using a K+ uptake deficient yeast mutant revealed that this amino acid change causes suppression of K+ channel function of ATCNGC11/12. Computational structural modeling suggests this position may be a key residue for functional channel formation. Log in to add this item to your schedule
1 - University of Toronto, Cell and Systems Biology 2 - University of Toronto, Cell and Systems Biology, 25 willcocks street, Toronto, ON, M5S3B2, Canada
Keywords: ion channel disease resistance CNGC.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P15080 Abstract ID:1924 |