Arabidopsis phosphatidylglycerophosphate phosphatase 1 involved in phosphatidylglycerol biosynthesis and photosynthetic function

Abstract

Phosphatidylglycerol (PG) is an indispensable lipid constituent of photosynthetic membranes, whose function is essential in photosynthetic activity. In higher plants, the biological function of the last step of PG biosynthesis remains elusive because an enzyme catalyzing this reaction step, namely phosphatidylglycerophosphate phosphatase (PGPP), has been a missing piece in the entire glycerolipid metabolic map. Here, we report the identification and characterization of AtPGPP1 encoding a PGPP in Arabidopsis thaliana. Heterologous expression of AtPGPP1 in yeast Δgep4 complemented growth phenotype and PG-producing activity, suggesting that AtPGPP1 encodes a functional PGPP. The GUS reporter assay showed that AtPGPP1 was preferentially expressed in hypocotyl, vasculatures, trichomes, guard cells, and stigmas. A subcellular localization study with GFP reporter indicated that AtPGPP1 is mainly localized at chloroplasts. A T-DNA-tagged knockout mutant of AtPGPP1, designated pgpp1-1, showed pale green phenotype with reduced PG and chlorophyll contents but no defect in embryo development. In the pgpp1-1 mutant, ultrastructure of plastids indicated defective development of chloroplasts and measurement of photosynthetic parameters showed impaired photosynthetic activity. These results suggest that AtPGPP1 is a primary plastidic PGPP required for PG biosynthesis and photosynthetic function in Arabidopsis.

Non‐specific phospholipases C, NPC2 and NPC6, are required for root growth in Arabidopsis

“…In the root tip, abnormally divided columella cells were frequently observed (Figure e–h). Although this phenotype is similar to the short roots with abnormal shape of columella cells observed in the pgpp1‐1 mutant, a knock‐out mutant of phosphatidylglycerophosphate phosphatase 1 (PGPP1) (Lin et al ., , ; Zhou et al ., ), a distinct phenotypic feature of the amiNPC2 npc6 ‐2 knock‐down lines is the chemical complementation of the phenotype by PCho supplementation. In plants, PCho is produced from PEtn by PMTs.…”

Arabidopsis Phosphatidic Acid Phosphohydrolases Are Essential for Growth under Nitrogen-Depleted Conditions

“…Moreover, the labeling percents were increased only in PAH1OE and PAH2OE throughout the time course. Thus, it may be that the plants are dying under N starvation but manage to maintain PG synthesis because PG is the essential lipid for photosynthesis ( Hagio et al, 2002 ; Kobayashi et al, 2015 , 2016 ; Lin et al, 2016 ). In pah1 pah2 , the labeling percent of PG and the other chloroplast lipids was significantly lower than WT, possibly because of the enhanced PC synthesis in pah1 pah2 and the decrease in PC breakdown even under N starvation.…”

High spatial resolution mass spectrometry imaging reveals the genetically programmed, developmental modification of the distribution of thylakoid membrane lipids among individual cells of maize leaf

“…GRMZM2G175401 and GRMZM2G097509, and both of them are expressed in shoots, especially at the tip of stage-2 leaves of V5 and V7, respectively (Sekhon et al, 2011). Furthermore, GRMZM2G175401 is shown to have a higher expression in M cells than BS cells, according to the supplementary data of Li et al (2010); however, the correlation between the content of 16:1t in PGs and FAD4 is obscure, as the reduction of 16:1t has been also reported for other mutants in PG biosynthesis such as pgpp1-1 and pgp1 (Babiychuk et al, 2003;Kobayashi et al, 2015;Lin et al, 2016).…”

“…Furthermore, GRMZM2G175401 is shown to have a higher expression in M cells than BS cells, according to the supplementary data of Li et al . (); however, the correlation between the content of 16:1t in PGs and FAD4 is obscure, as the reduction of 16:1t has been also reported for other mutants in PG biosynthesis such as pgpp1‐1 and pgp1 (Babiychuk et al ., ; Kobayashi et al ., ; Lin et al ., ).…”