METABOLIC CHANGES OF Portulaca oleracea UNDER DROUGHT STRESS CONDITIONS

D'ANDREA, RODRIGO MATIAS; ANDREO, CARLOS SANTIAGO; LARA, MARÍA VALERIA

San Miguel de Tucumán, Tucumán, Argentina

Congreso; XLV Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Portulaca oleracea is a C4 plant; however, under severe droughtstress conditions it can change its carbon fixation metabolism into aCAM-like one. This work was carried out to answer whether thelevels of small molecule metabolites such as osmoprotectants, freeamino acids, organic acids and sugars are affected by strict droughtstress in P. oleracea. Metabolic profile of this species under wateredconditions and after withholding water during 21 days wasperformed in leaves through gas chromatography coupled withmass spectrometry (GS-MS). Several metabolites were identifiedin compositional analyses, such as organic acids; sugars;aminoacids; alcohols; and urea. However, only four analytes, urea,phenylalanine, pinitol and xilitol showed a significant droughtinduceddifference between well-watered and water-restrictedsamples, and other metabolites, such as malate, glutamine, alanine,galactose, glucose, fructose showed a significant differencebetween well-watered and water-restricted samples only atdifferent time during the day, in agreement with the change in thetype of photosynthetic metabolism. This work provides evidencesuggesting that the change in the levels of several metabolites isimportant to resist drought stress conditions and to maintain CAMlikemetabolism in P. oleracea.