Abstract
Plant flotillins, a subgroup of the SPFH domain protein superfamily, consist of three proteins, AtFLOT1, AtFLOT2, and AtFLOT3 in Arabidopsis thaliana. The exact functions of flotillins in plant cell has not been established yet.
In this study we focused on the role of flotillins in response to both abiotic and biotic stresses and on the response to phytohormones abscisic acid and 1-naphthalene acetic acid (NAA) in A. thaliana. We observed transcriptomic changes of AtFLOT genes in response to high salinity and cold, treatment with 22-amino acid peptide from N-terminal part of flagellin (flg22), and after infection with Botrytis cinerea.
Transcription of AtFLOT2 increased up to 60 times after flg22 treatment. Also, treatment with B. cinerea increased transcription of AtFLOT1 10 times and of AtFLOT3 14 times.
Furthermore, we used T-DNA knock-out single mutants for all three A. thaliana flotillins and we measured root growth in response to high salinity, cold, phosphate starvation, nitrogen starvation, and abscisic acid and NAA treatments. Subsequently, we measured the reactive oxygen species production and callose accumulation after the treatment with flg22.
Next, we performed resistance assays to Pseudomonas syringae pv. tomato DC3000 and B. cinerea. In contrast to transcriptomic changes, knocking-out of only single FLOT gene did not lead to significant changes in response to all tested stresses.