Poster abstracts

Poster number 118 submitted by Katelyn Amstutz

Determining the role of a plant LINC complex in stomatal closure

Katelyn Amstutz (Molecular, Cellular, and Developmental Biology Graduate Program), Norman R. Groves (Department of Molecular Genetics, The Ohio State University), Iris Meier (Department of Molecular Genetics, The Ohio State University)

Abstract:
As climate change worsens, droughts across the globe have increased in frequency and severity. Understanding how plants regulate and resist drought stress will allow us to better create crops resilient to the changing climate. In response to drought, plants use the hormone Abscisic Acid to signal to pores called stomata, which are formed from two guard cells surrounding a central pore, to close. Loss of the Arabidopsis Klarsicht/ANC-1/Syne Homology (KASH) proteins AtSINE1 or AtSINE2 inhibits ABA-induced stomatal closure due to a decrease in calcium fluctuations and defects in actin reorganization. KASH proteins are outer nuclear membrane (ONM) members of the Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes, and interact with inner nuclear membrane SUN proteins. KASH proteins have a cytoplasmic region which interacts with the cytoskeleton, while SUN proteins can interact with the nuclear lamina. However, whether these interactions are important for SINE1 or SINE2 function during stomatal closure is unknown. In addition, the role of SUN proteins and the nuclear lamina in stomatal closure has not been determined.
Here, we have asked whether (a) nuclear envelope association, (b) membrane association, and (c) cytoplasmic regions are involved in SINE1 and SINE2 function in stomatal closure. Protein fragments with respective domain deletions have been tagged with GFP and placed under native promoters into sine1-1 and sine2-1 mutants. Subcellular localizations have been confirmed, and the effect of these associations and interactions on stomatal closure has been examined. We further examined whether SUN and nuclear lamina components are required for stomatal closure by examining ABA-induced stomatal closure in a sun double mutant, sun1-KO sun2-KD, and two nuclear lamina mutants, crwn1 and crwn4.

Keywords: LINC complex, Stomata, Nucleus