PLD/PA MODULATES PROLINE AND H2O2 LEVELS IN BARLEY EXPOSED TO SHORT-AND LONG-TERM CHILLING STRESS

PEPPINO MARGUTTI, MICAELA; REYNA, MATIAS; RACAGNI, GE; VILLASUSO, ANA LAURA

Córdoba

Congreso; SAIB.52 th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016

PLD/PA MODULATES PROLINE AND H2O2 LEVELS IN BARLEY EXPOSED TO SHORT-ANDLONG-TERM CHILLING STRESSPeppino Margutti MY, Reyna M, Racagni GE, VillasusoAL.Dpto de Biología Molecular. Universidad Nacional de Río Cuarto. E-mail: mpeppino@exa.unrc.edu.arPLD hydrolyses phospholipids to produce PA and a head groupand it is involved in the response to various environmental stresses. Inthis work, we investigated the roles of PLD/PA inresponse to short and long-termchilling stress through theregulation of proline andROS levels in barley. Seedling grown at 25ºC for 4d were maintained at 4ºC for 0.536h. Short-termchilling stress increased rapidly andtransiently the PLD activityand modulated proline and ROS levels in young leaves. Pre-treatmentwith 1-butanolaugmented the prolinesynthesis, andthe treatment with PA exogenous amplified H2O2formation. In contrast, long-term chilling stress reduced enzymaticactivity ofPLD; while the proline synthesis and the ROS signal were stimulated in roots. H2O2 application stimulated the prolinelevelwhile the exogenous proline decreased the ROS level.Bioinformatic search of the barley database revealed thepresence of highlyhomologous sequences of P5CS and ProDHArabidopsis protein. Ours results indicate that PLD contributesto the signalling pathwayduring 0.53hat 4°C through theregulation of balance between P5CS activity and H2O2 level.On the contrary, reduced enzymaticactivity of PLD during 2436hat 4°C could not contribute to the proline level. Thissuggests that PLD/PA signal is involved in therelationshipbetween ROS signalling and proline metabolism.