Distribution of glycosylinositol phosphoceramide-specific phospholipase D activity in plants

Previously, we detected an unknown sphingophospholipid in cabbage leaves and identified it as phytoceramide-1-phosphate (PC1P). We also found an enzyme activity that produces PC1P by glycosylinositol phosphoceramide (GIPC)-specific hydrolysis in cabbage leaves. To characterize the GIPC-specific phospholipase D (GIPC-PLD) activity, we investigated distributions of GIPC-PLD activity in 25 tissues of 10 plants. In most plants, the GIPC-PLD activity was the highest in roots. Young leaves of cabbage and Welsh onion had higher activities than corresponding aged outer leaves. The GIPC-PLD activities in leaves, stems and roots of mung bean were higher in the sprouting stage than in more mature stages. We also examined distribution of substrate GIPC and product PC1P, and found that GIPC was ubiquitously distributed at 50-280 nmol/g (wet wt) in tissues of plants, whereas PC1P was detectable (3-60 nmol/g wet wt.) only in tissues showing considerable GIPC-PLD activity. These results suggest a possibility that GIPC-PLD activity is involved in plant growth.

This is a pre-copyedited, author-produced version of an article accepted for publication in The Journal of Biochemistry following peer review. The version of record Takashi Kida, Aoi Itoh, Akari Kimura, Hisatsugu Matsuoka, Hiroyuki Imai, Kentaro Kogure, Akira Tokumura, Tamotsu Tanaka, Distribution of glycosylinositol phosphoceramide-specific phospholipase D activity in plants, The Journal of Biochemistry, Volume 161, Issue 2, February 2017, Pages 187–195, is available online at: https://doi.org/10.1093/jb/mvw060.