Phospholipase Dε and phosphatidic acid enhance Arabidopsis nitrogen signaling and growth

• Published in: The Plant journal : for cell and molecular biology Vol. 58; no. 3; pp. 376 - 387
• Main Authors: Hong, Yueyun, Devaiah, Shivakumar P, Bahn, Sung Chul, Thamasandra, Bharath N, Li, Maoyin, Welti, Ruth, Wang, Xuemin
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.05.2009; Blackwell Publishing Ltd; Blackwell
• Subjects: Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; biomass; Cell physiology; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Gene Knockout Techniques; Genes, Plant; Molecular and cellular biology; Mutagenesis, Insertional; Nitrates - metabolism; Nitrogen - metabolism; nitrogen signaling; phosphatidic acid; Phosphatidic Acids - metabolism; phospholipase D; Phospholipase D - metabolism; plant growth; Plant Roots - enzymology; Plant Roots - genetics; Plant Roots - growth & development; RNA, Plant - metabolism; Signal Transduction; plant growth; Vegetals; Enzyme; Growth; Esterases; Phosphoric diester hydrolases; Biomass; Nitrogen; Phospholipase D; Cell signaling; Arabidopsis thaliana; Plant; Cruciferae; Dicotyledones; Angiospermae; Hydrolases; Spermatophyta; nitrogen signaling; Phosphatidic acid
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2009.03788.x

Activation of phospholipase D (PLD) produces phosphatidic acid (PA), a lipid messenger implicated in cell growth and proliferation, but direct evidence for PLD and PA promotion of growth at the organism level is lacking. Here we characterize a new PLD gene, PLDε, and show that it plays a role in promoting Arabidopsis growth. PLDε is mainly associated with the plasma membrane, and is the most permissive of all PLDs tested with respect to its activity requirements. Knockout (KO) of PLDε decreases root growth and biomass accumulation, whereas over-expression (OE) of PLDε enhances root growth and biomass accumulation. The level of PA was higher in OE plants, but lower in KO plants than in wild-type plants, and suppression of PLD-mediated PA formation by alcohol alleviated the growth-promoting effect of PLDε. OE and KO of PLDε had opposite effects on lateral root elongation in response to nitrogen. Increased expression of PLDε also promoted root hair elongation and primary root growth under severe nitrogen deprivation. The results suggest that PLDε and PA promote organism growth and play a role in nitrogen signaling. The lipid-signaling process may play a role in connecting membrane sensing of nutrient status to increased plant growth and biomass production.