Phospholipase Dε and Phosphatidic Acid Enhance Arabidopsis 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, SungChul, Thamasandra, Bharath N., Li, Maoyin, Welti, Ruth, Wang, Xuemin
• Format: Journal Article
• Language: English
• Published: 08.01.2009
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2009.03788.x

The activation of phospholipase D (PLD) produces phosphatidic acid (PA), a new lipid messenger implicated in cell growth and proliferation, but direct evidence for PLD and PA promotion of growth at an organismal level is lacking. Here we characterized a new PLD, PLDε , and show that PLDε plays a role in promoting Arabidopsis growth. PLDε is mainly associated with the plasma membrane and is the most permissive of all PLDs tested in activity requirements. Knockout (KO) of PLDε decreases, whereas overexpression (OE) of PLDε enhances root growth and biomass accumulation. The level of PA was higher in OE, but lower in KO 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 the opposite effect on lateral root elongation in response to nitrogen (N). Increased expression of PLDε also promoted root hair elongation and primary root growth at severe N deprivation. The results suggest that PLDε and PA promote organismal growth and play a role in N response. The lipid signaling process may play a role in translating the membrane sensing of nutrient status to increasing plant growth and biomass production.