MSc Exit Seminar – Alexander Fortuna (Yoshioka lab)

MSc Exit Seminar

Tuesday September 29th, 2:30 pm – Earth Sciences Centre, Rm. 3087

Alexander Fortuna (Yoshioka lab) 

“Investigating the Interplay of Cyclic Nucleotide Gated Ion Channel 2 and Auxin in Immunity Signaling”

Abstract

Cyclic nucleotide-gated channels (CNGCs) are non-selective, ligand-gated cation channels present across eukaryotes. CNGCs were first identified in animals, where their functions in vertebrate photo-sensory and olfactory neurons are well characterized. Comparably little is known about the physiological roles or biophysical properties of plant CNGCs. In Arabidopsis, the CNGC family contains 20 members, which are believed to play important roles in biotic and abiotic stress responses, ion homeostasis, and development through their Ca²⁺ conducting abilities. Several CNGCs have been implicated in plant-pathogen interactions through genetic studies. The defense, no death mutants dnd1 and hlm1/dnd2, which are null mutants of the closely related Arabidopsis CNGCs, CNGC2 and CNGC4 have distinct autoimmune phenotypes. This includes elevated levels of salicylic acid, constitutive expression of Pathogenesis Related genes and broad spectrum disease resistance. Though these mutants have been well characterized phenotypically, CNGC-mediated signal transduction is poorly understood.

In order to understand CNGC2-mediated defense signaling, I have investigated the first dnd1 suppressor mutant, repressor of defense no death 1 (rdd1-1D). In this work, I aimed to understand the molecular mechanism by which rdd1-1D is able to suppress dnd1-conferred phenotypes. Current data indicates that rdd1-1D is a loss-of-function mutation in the auxin biosynthesis gene YUCCA6.