Expression Profiles of 2 Phosphate Starvation-Inducible Phosphocholine/Phosphoethanolamine Phosphatases, PECP1 and PS2, in Arabidopsis

Abstract

Phosphorus is essential for plant viability. Phosphate-starved plants trigger membrane lipid remodeling to replace membrane phospholipids by non-phosphorus galactolipids presumably to acquire scarce phosphate source. Phosphoethanolamine/phosphocholine phosphatase 1 (PECP1) and phosphate starvation-induced gene 2 (PS2) belong to an emerging class of phosphatase induced by phosphate starvation and dephosphorylates phosphocholine and phosphoethanolamine (PEtn) in vivo . However, detailed spatiotemporal expression pattern as well as subcellular localization has not been investigated yet. Here, by constructing transgenic plants harboring functional translational promoter–reporter fusion system, we showed the expression pattern of PECP1 and PS2 in different tissues and in response to phosphate starvation. Besides, the Venus fluorescent reporter revealed that both are localized at the ER. Characterization of transgenic plants that overexpress PECP1 or PS2 showed that their activity toward PEtn may be different in vivo . We suggest that PECP1 and PS2 are ER-localized phosphatases that show similar expression pattern yet have a distinct substrate specificity in vivo.

Growth and bioactive phytochemicals of Panax ginseng sprouts grown in an aeroponic system using plasma-treated water as the nitrogen source

“…For P. ginseng growth, the P-starved root might require some metabolism of P-containing proteins to cope with the P starvation. Under a P-starved condition, a slight but significant reduction of phosphoethanolamine was detected in Arabidopsis roots; this result indicates that phosphoethanolamine can be dephosphorylated in the phospholipids under P starvation 40,41 .…”

“…The P. ginseng sprouts might respond to the P deficiency in our study even though N and K were readily available for rapid growth. Under the P-starved condition, metabolic conversion of phosphoethanolamine to 2-aminoethanol occurs in the phospholipids to cope with the P starvation 40 , 41 . Following the decrease of phosphoethanolamine, methionine might be required less in P. ginseng sprouts as a methyl group donor for phosphoethanolamine.…”

Rice ACID PHOSPHATASE 1 regulates Pi stress adaptation by maintaining intracellular Pi homeostasis

“…AtPECP1 displayed significant specific activity for PEA and PCho in vitro (May et al, 2012). A subsequent study showed that both AtPECP1 and AtPECP2 are involved in PEA and PCho metabolism in vivo (Angkawijaya et al, 2019; Angkawijaya & Nakamura, 2017; Hanchi et al, 2018). Although the recombinant OsACP1 protein shows the highest activity for PEA as AtPECP1 does, OsACP1 can also effectively hydrolase several other kinds of Po (Figure 3).…”

“…OsHAD1 , which is renamed as OsHAD12 by phylogenetic analysis, is proposed to regulate Pi acquisition by dephosphorylation of downstream target proteins in the cytosol (Pandey et al, 2017). AtPECP1 and AtPECP2 (also name as AtPS2/AtPPsPase1), are reported to hydrolyse phosphocholine (PCho) and phosphoethanolamine (PEA) under Pi starvation conditions in Arabidopsis (Angkawijaya & Nakamura, 2017; Angkawijaya, Ngo, Nguyen, Gunawan, & Nakamura, 2019; Hanchi et al, 2018; Tannert et al, 2018).…”

At4g29530 is a phosphoethanolamine phosphatase homologous to PECP1 with a role in flowering time regulation

“…Further in vitro studies revealed that another phosphatase, PPsPase1/PS2/PECP2 (phosphate starvation gene 2; At1g73010), exhibited the highest substrate activity for pyrophosphate, but also showed activity for PEtn and PCho (May et al, 2011). It is assumed that PPsPase1/PS2/ PECP2 also functions as PEC-phosphatase and uses PEtn/ PCho as substrates in vivo, because both phosphatases belong to the same HAD-like phosphatase family and are co-expressed under phosphate starvation (Angkawijaya et al, 2019;Hanchi et al, 2018). Recently, a gene sequence homologous to PECP1 and PPsPase1/PS2/PECP2 was described.…”