Transcriptome analysis of cell-specific JAZ4 regulation of plant responses in Arabidopsis
L. DEMOTT (1), P. Oblessuc (1), M. Melotto (1) (1) University of California - Davis, U.S.A.

Phytohormone signaling pathways mediate many plant responses to both biotic and abiotic stimuli.  The vast complexity of interconnection between these pathways is still being resolved.  Our previous work has shown that the bacterial phytotoxin coronatine (COR) produced by Pseudomonas syringae pv. tomato (Pst) DC3000 requires a functional JAZ4 (Jasmonate-ZIM Domain 4) protein to overcome stomatal immunity, while a functional JAZ4 contributes to apoplastic immunity towards this pathogen.  In order to understand what mechanisms are mediated by JAZ4 in these different cell types, we compared the baseline transcriptome profiles of wild-type (Col-0) Arabidopsis and jaz4 null mutant in both guard cells (GC) and whole leaf (WL) samples, as well as their transcriptional changes in response to COR treatment.  Based on gene ontology (GO) analysis, JAZ4 seems to control genes involved in plant response to different stimuli, such as light, temperature, acid compounds, as well as phytohormones. The jaz4 GC treated with COR showed differential expression of genes related to stomatal movement and cell division, correlating with previous data showing reduced stomatal aperture size in jaz4 plants in relation to Col-0. Finally, GO analysis showed that COR regulates a different set of genes in GC as compared to WL. These results revealed a complex JAZ4-mediated regulatory network, which seems to differ among cell types suggesting the existence of multiple molecular functions for this protein.

Abstract Number: P16-447
Session Type: Poster