Vol.:(0123456789) 1 3 J Plant Res DOI 10.1007/s10265-017-0923-7 REGULAR PAPER Synthesis and degradation of long-chain base phosphates affect fumonisin B 1 -induced cell death in Arabidopsis thaliana Daiki Yanagawa 1,2  · Toshiki Ishikawa 3  · Hiroyuki Imai 1,2   Received: 10 October 2016 / Accepted: 7 December 2016 © The Botanical Society of Japan and Springer Japan 2017 LCBK1-OX and -KD plants showed resistance and sensi- tivity to FB 1 , respectively, whereas free LCB and LCBP levels in FB 1 -treated LCBK1-OX and -KD plants were moderately different to those in FB 1 -treated WT plants. Overall, the findings described here suggest that LCBP/ LCB homeostasis is an important topic that participates in the tolerance of plant cells to FB 1 . Keywords Fumonisin B 1  · Long-chain base kinase · Long-chain base phosphates · LC-MS/MS · Sphingolipid catabolism Abbreviations CaMV35S Cauliflower mosaic virus 35S Cer Ceramide DPL LCBP lyase d17:1 C 17 -E-4-sphingenine d17:1-P C 17 -E-4-sphingenine-1-phosphate d18:0 Sphinganine (dihydrosphingosine) d18:0-P Sphinganine (dihydrosphingosine)-1-phosphate d18:1(4E) E-4-sphingenine (sphingosine) d18:1(4E)-P E-4-sphingenine (sphingosine)-1-phosphate d18:1(8Z) Z-8-sphingenine d18:1(8Z)-P Z-8-sphingenine-1-phosphate d18:1(8E) E-8-sphingenine d18:1(8E)-P E-8-sphingenine-1-phosphate ESI Electrospray ionization FB 1 Fumonisin B 1 GlcCer Glucosylceramide GIPC Glycosyl inositolphosphoceramide HPLC High-performance liquid chromatography HR Hypersensitive response LC Liquid chromatography LCB Long-chain base Abstract Fumonisin B 1 (FB 1 ), an inducer of cell death, disrupts sphingolipid metabolism; large accumulations of de novo synthesized free long-chain bases (LCBs) are observed. However, it remains unclear whether tolerance to FB 1 toxicity in plants is connected with preventing the accumulation of free LCBs through their phosphorylation. Here a workflow for the extraction, detection and quantifi- cation of LCB phosphates (LCBPs) in Arabidopsis thaliana was developed. We studied the effect of expression of genes for three enzymes involved in the synthesis and degrada- tion of LCBPs, LCB kinase (LCBK1), LCBP phosphatase (SPP1) and lyase (DPL1) on FB 1 -induced cell death. As expected, large accumulations of saturated free LCBs, dihydrosphingosine and phytosphingosine, were observed in the FB 1 -treated leaves. On the other hand, a high level of sphingenine phosphate was found in the FB 1 -treated leaves even though free sphingenine was found in low amounts in these leaves. In comparison of WT and spp1 plants, the LCBP/LCB ratio is likely to be correlated with the degree of FB 1 -induced cell death determined by trypan blue stain- ing. The FB 1 -treated leaves in dpl1 plants showed severe cell death and the elevation of free LCBs and LCBPs. Electronic supplementary material The online version of this article (doi:10.1007/s10265-017-0923-7) contains supplementary material, which is available to authorized users. * Hiroyuki Imai imai@konan-u.ac.jp 1 Department of Biology, Graduate School of Natural Science, Konan University, Kobe 658-8501, Japan 2 The Institute for Integrative Neurobiology, Konan University, Kobe 658-8501, Japan 3 Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan