ARS | Publication request: Suppression of phospholipase D,gammas confers increased aluminum resistance in Arabidopsis thaliana

Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 31, 2011
Publication Date: December 7, 2011
Repository URL: http://handle.nal.usda.gov/10113/55214
Citation: Zhao, J., Wang, C., Welti, R., Bedair, M., Sumner, L., Baxter, I.R., Wang, X. 2011. Suppression of phospholipase D,gammas confers increased aluminum resistance in Arabidopsis thaliana. PLoS One. 6(12):e28086. Available: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0028086.

Interpretive Summary: Aluminum (Al) toxicity is the major stress in acidic soil that comprises about 50% of the world’s arable land. Al has the potential to affect multiple different cellular systems controlling many different plant processes. As a result, it has been difficult to determine which processes are most susceptible to Al toxicity. One such property is the lipid composition of the membranes of the plant cell which effects the properties of the membrane and therefore it’s ability to mediate many different processes. We studied the affects of Al treatment on plants where enzymes that are involved in the proccessing of these lipids were genetically impeded. We showed that altering the levels of these enzymes alters the ability of the plants to withstand Al stress. These findings offer a novel strategy to improve tolerance to acid soils and aluminum toxicity of all major crops thus impacting world food security in a positive fashion.

Technical Abstract: Aluminum (Al) toxicity is the major stress in acidic soil that comprises about 50% of the world’s arable land. The complex molecular mechanisms of Al toxicity have yet to be fully determined. As a barrier to Al entrance and attack, plant cell membranes play essential roles in Al toxicity, as lipid composition and membrane integrity change significantly under Al stress. We have shown that phospholipase D's (PLD's) are induced by Al stress and play a role in Al-induced membrane lipid alterations. RNAi suppression of PLD' resulted in a decrease in both PLD'1 and PLD'2 expression and an increase in Al resistance. Genetic disruption of PLD'1 also led to an increased tolerance to Al while knockout of PLD'2 did not. Both RNAi-suppressed and pld'1-1 mutants displayed better root growth than wild-type under Al stress conditions, and PLD'1-deficient plants had less accumulation of callose, less oxidative damage, and less lipid peroxidation compared to wild-type plants. Most phospholipids and glycolipids were altered in response to Al treatment of wild-type plants, whereas fewer changes in lipids occurred in response to Al stress in PLD' mutant lines. Our results suggest that PLD's play a role in membrane lipid modulation under Al stress and that high activities of PLD's negatively modulate plant tolerance to Al.