Deciphering the mechanisms involved in Portulaca oleracea (C4) response to drought: metabolic changes including crassulacean acid-like metabolism induction and reversal upon re-watering.

摘要: Portulaca oleracea is a C(4) plant; however, under drought it can change its carbon fixation metabolism into crassulacean acid (CAM)-like one. While the C(3) -CAM shift well known, transition has only been described in Portulaca. Here, CAM-like was induced P. by and then reversed re-watering. Physiological biochemical approaches were undertaken to evaluate recovery responses. In plants, chlorophyll fluorescence parameters transitory affected non-radiative energy dissipation mechanisms induced. Induction of flavonoids, betalains antioxidant machinery may be involved photosynthetic protection. Metabolic analysis highlights clear metabolic shift, when reversed. Increases nitrogenous compounds like free amino acids urea, pinitol could contribute withstand drought. Reciprocal variations arginase urease drought-stressed re-watered plants suggest urea synthesis strictly regulated. Recovery accounted CO(2) assimilation pattern malate levels. glycerol polyamines would importance plants. Collectively, multiple strategies, from induction several metabolites development metabolism, participate enhance adaptation