Colorful Signaling: Resolving cellular salicylic acid and jasmonate/ethylene responses during Hyaloperonospora arabidopsidis-Arabidopsis thaliana interactions
S. LAUKAMM (1), V. Lipka (2), O. Tetyuk (2), A. von Hoyningen-Huene (2), M. Pound (3), K. Hanika (4), H. Ghareeb (2) (1) Georg-August-University Göttingen, Germany; (2) Georg-August-Universität Göttingen, Germany; (3) University of Nottingham, England; (4) University of Wageningen, Netherlands

The interaction between Hyaloperonospora arabidopsidis and Arabidopsis has been a valuable model for understanding biotrophy and R gene-mediated immune responses. Several approaches, such as hormone quantification, measurement of marker gene expression as well as mutant analysis have been used to investigate the fundamental role of salicylic acid in mediating defense responses against H. arabidopsidis. However, these approaches are invasive and largely constrained to tissue levels. To better understand hormone signaling dynamics during the H. arabidopsidis-Arabidopsis interactions at cellular resolution, we used our recently established fluorescent proteins-based hormone biosensors called ‘COLORFUL biosensors’ in combination with a high-throughput imaging platform. Our results show that during incompatible interactions with the isolate Emwa1 SA signaling is limited to confined areas surrounding the infection sites. Interestingly, we observed spatio-temporally controlled SA response gradients within and between the epidermal and mesophyll cell layers. Reporters for JA/ET signaling show similar but reciprocal JA/ET response gradients, likely reflecting the antagonistic activities of the two signaling pathways. These findings suggest that our ‘COLORFUL biosensors’ system provides a valuable tool to resolve cell autonomous and non-autonomous signaling pathways as well as the dynamics of hormone-dependent intercellular communication processes during plant-microbe interactions.

Abstract Number: C12-4, P15-436
Session Type: Concurrent