Arabidopsis non-specific phospholipase C1: characterization and its involvement in response to heat stress

Abstract

The Arabidopsis non-specific phospholipase C1 (NPC) protein family is encoded by the genes NPC1 – NPC6. It has been shown that NPC4 and NPC5 possess phospholipase C activity; NPC3 has lysophosphatidic acid phosphatase activity. NPC3, 4 and 5 play roles in the responses to hormones and abiotic stresses. NPC1, 2 and 6 has not been studied functionally yet. We found that Arabidopsis NPC1 expressed in Escherichia coli possesses phospholipase C activity in vitro. This protein was able to hydrolyse phosphatidylcholine to diacylglycerol. NPC1-green fluorescent protein was localized to secretory pathway compartments in Arabidopsis roots. In the knock out T-DNA insertion line NPC1 (npc1) basal thermotolerance was impaired compared with wild-type (WT); npc1 exhibited significant decreases in survival rate and chlorophyll content at the seventh day after heat stress (HS). Conversely, plants overexpressing NPC1 (NPC1-OE) were more resistant to HS compared with WT. These findings suggest that NPC1 is involved in the plant response to heat.

Non‐specific phospholipase C1 affects silicon distribution and mechanical strength in stem nodes of rice

“…NPC1 protein was found in the plasma and intracellular membranes with most being associated with the intracellular membranous fraction (Figure S2c). Subcellular localization using NPC1:GFP fusion indicated that NPC1 in Arabidopsis is mostly associated with the intracellular membranes (Krčková et al ., ).…”

“…The amino acid sequences of NPC4 and NPC5 are more closely related to one another than to NPC1. A recent study found that NPC1 from Arabidopsis hydrolyzed PC and its activity to other lipids were not tested (Krčková et al ., ). The present results indicate that NPC1 hydrolyzes both phospholipids and galactolipids.…”

“…In terms of gene structure and amino acid sequences, NPC3, NPC4, and NPC5 are more closely related to each other than to other NPCs. A recent study indicated that NPC1 positively mediates Arabidopsis response to heat stress (Krčková et al ., ).…”

Nonspecific phospholipase C6 increases seed oil production in oilseed Brassicaceae plants

“…NPC6 hydrolyzed PC in vitro , and in vivo labelling indicates that NPC6 ‐KO reduces, but OE accelerates, PC and galactolipids turnover to TAG production in seeds. Among the six NPCs in Arabidopsis, NPC6 was unique, being associated with both the chloroplast and microsomal membrane fractions, whereas other NPCs are associated with cytosol (NPC5), the plasma membrane (NPC4), tonoplasts (NPC3) and endomembranes (NPC1 and NPC2) based on experimental data and sequence predictions (Carter et al , 2004; Peters et al , 2010; Peters et al , 2014; Krčková et al , 2015, 2017; Ngo et al , 2018). In addition, NPC6 hydrolyzes galactolipids (monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG)), and its association with chloroplasts suggests that NPC6 has the access to plastidic galactolipids to release DAG.…”

“…The Arabidopsis genome has six NPCs involved in various plant processes. NPC1 and NPC2 were involved in response to heat and P. syringae attack, respectively (Krčková et al , 2015, 2017). NPC3 and NPC4 had roles in root development and brassinolide signalling (Wimalasekera et al , 2010), and NPC4 plays a role in response to salt, abscisic acid (Peters et al , 2010), phosphate starvation (Nakamura et al , 2005; Su et al , 2018) and aluminum toxicity (Pejchar et al , 2015).…”