Changes in biomass allocation and phenolic compounds accumulation due to the effect of light and nitrate supply in Cecropia peltata plants

• Published in: Acta physiologiae plantarum 2011, Vol.33 (6), p.2135-2147
• Main Authors: Mora Izquierdo, Alejandro, Nicasio Torres, María del Pilar, Sepúlveda Jiménez, Gabriela, Cruz Sosa, Francisco
• Format: Article
• Language: English
• Subjects: aerial parts; Agriculture; antioxidant activity; biomass production; Biomedical and Life Sciences; carbon; Cecropia peltata; chlorogenic acid; dry matter partitioning; leaves; Life Sciences; light intensity; nitrates; nutrient balance; Original Paper; oxidative stress; phenolic compounds; phenylalanine ammonia-lyase; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; root growth; root shoot ratio; roots; soil nutrients
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-011-0753-5

Cecropia peltata is popularly known as “guarumbo” in Mexico and is used in traditional medicine for treatment of diabetes mellitus. C. peltata plants were cultivated in a hydroponic system under controlled conditions. Gradients of light (20, 30 and 100 μmol m−2 s−1) and nitrate concentrations (13, 2 and 0.2 mM) were applied to estimate their effect on biomass allocation and accumulation of bioactive (chlorogenic acid and isoorientin) phenolic compounds over a 28-day period. According to carbon nutrient balance (CNB) hypothesis predictions, biomass accumulation in foliage was stimulated by the highest irradiance (100 μmol m−2 s−1); similarly, at highest irradiance in combination with lowest nitrate concentration (0.2 mM), root growth was stimulated (root-to-shoot ratio increased twofold with respect to the control). In these conditions, total phenolics (TP) and chlorogenic acid (CGA) contents were higher in aerial parts than in roots, with a 3.8-fold increase in TP and a 7.7-fold increase in CGA in foliage with respect to the control plants. Isoorientin was accumulated at very low levels. Antioxidant activity and total phenolic content showed a strong positive correlation. Phenylalanine ammonia-lyase activity (PAL) in aerial parts exhibited significant changes (>twofold) by highest irradiance. C. peltata plants allocate biomass and/or phenolic compounds to compensate the oxidative damage (increase in MDA levels) due to changes in light and nitrate restriction. The results are the basis for the establishment of a system of C. peltata culture in view of the potential use of C. peltata in therapeutic preparations for the treatment of diabetes mellitus.