Effects of phenol on the phospholipid turnover and phospholipase D activity in transgenic tobacco hairy roots

SOSA ALDERETE, LG; RACAGNI, G; AGOSTINI E.; MEDINA, MI

Mérida

Congreso; Cell Signalling Network, 13th Internacional Union of Biochemistry and Molecular Biology (IUBMB) Conference, 1st Panamerican Association of Biochemistry and Molecular Biology (PABMB). Conference and 3rd meeting of Signal transduction and Oxidative Stress B; 2011

Effects of phenol on the phospholipid turnover and phospholipase D activity in transgenic tobacco hairy roots Sosa Alderete L. G., Racagni G., Agostini E. and Medina M.I. Departamento de Biología Molecular, FCEFQyN, Universidad Nacional de Río Cuarto (UNRC), Ruta Nacional 36 Km 601, CP 5800 Río Cuarto, Córdoba, Argentina. E-mail: mmedina@exa.unrc.edu.ar The increased release of different organic pollutants to the ecosystem, such as phenol, can produce a stressful condition affecting the development and plant growth. In this work, we studied the effects of phenol on the [32P]phospholipid turnover and phospholipase D (PLD) activity, using tobacco hairy roots (HRs), double transgenic (DT) for two peroxidase genes from tomato (tpx1 and tpx2). Differences in the [32P]phospholipid turnover of minor phospholipids (PLs) were observed in DT HRs compared to wild type (WT) ones. In the latter, phenol exposure significantly increases the turnover of phosphatidic acid (PA) and phosphatydilinositol (PI), whereas in DT HRs, significant increase in the turnover of PI, lisophosphatidic acid (LPA), diacylglycerolpyrophosphate (DGPP) and PA with a concomitant decrease in the phosphatidylinositol monophosphate (PIP) were detected. In addition, phosphatidylinositol bisphosphate (PIP2) was identified, but its level did not change in the presence of the pollutant. The turnover of the most abundant PLs, such as phosphatidylcholine (PC), phosphatydilethanolamide (PE), phosphatydilglycerol (PG) and cardiolipin (CL), from both HRs, did not show any changes after pollutant exposure. Phenol treatment significantly increased the PLD activity in WT and DT HRs, being 100% and 50% higher than the controls, respectively. These results suggest the participation of minor PLs, like PA, and the PLD pathway, as one active source of PA production, in the activation of intracellular mechanisms that may be involved in the response of these plant tissues to phenol exposure.