Potato stolons: Lipid molecular species

CENZANO A, RACAGNI G, ABDALA G.

Huerta Grande, Córdoba, Argentina

Jornada; XVII Annual Scientific Meeting of Córdoba Biology Society; 2009

Sociedad de Biología de Córdoba

Phospholipids, galactolipids and fatty acids esterified are involved in signaling pathways triggered by biotic and abiotic stress. However, their participation in the process of plant development, such as tuberization of Solanum tuberosum L. is still limited. Therefore, we evaluated by ESI-MS/MS the lipid composition and molecular species of potato stolons, controls and stimulated with jasmonic (JA), abscisic and gibberellic acid. In control stolons, phosphatidic acid (PA) was the majority, followed by digalactosyldiacylglicerol (DGDG) and phosphatidylinositol (PI); monogalactosyldiacylglicerol (MGDG), phosphatidylcholine (PC), phosphatidylglycerol (PG) had intermedia levels, and phosphatidylethanolamine (PE), phosphatidylserine (PS) and the lysophospholipids exhibited the lowest levels. The hormonal treatment produced no significant changes. The presence of 34:2 in PE, PC, PI and PA supports the hydrolysis of PC and PE by phospholipase D and the hydrolysis of PI by phospholipase C, leading both to 34:2 PA production. In MGDG and DGDG 36:6 was abundant and their hydrolysis could release the substrate (18:3) for the biosynthesis of JA. The identity of the molecular species allows us inference the lipid metabolism pathways activated at the start of potato tuber formation and the prevalence of PA and DGDG as constituents of photosynthetic membranes and nonphotosynthetic plastid.