Involvement of sphingosine kinase in plant cell signalling

摘要: In mammalian cells sphingosine-1-phosphate (S1P) is a well-established messenger molecule that participates in wide range of signalling pathways. The objective the work reported here was to investigate extent which phosphorylated long-chain sphingoid bases, such as and phytosphingosine-1- phosphate (phytoS1P) are used plant cell signalling. To do this, we manipulated Arabidopsis genes capable metabolizing these molecules. We show Sphingosine kinase1 (SPHK1) encodes an enzyme phosphorylates sphingosine, phytosphingosine other bases. stomata SPHK1-KD plants were less sensitive, whereas SPHK1-OE more than wild type ABA. rate germination enhanced, converse true for seed. Reducing expression either putative S1P phosphatase (SPPASE) or DPL1 gene, with lyase activity, individually, had no effect on guard-cell ABA signalling; however, stomatal responses SPPASE RNAi compromised. germination; seeds sensitive applied also found evidence SPHK1 coordinately regulated, discuss how this might contribute robustness summary, our data establish component two separate systems, opening possibility bases phytoS1P ubiquitous messengers plants.