Zinc and Iron Biofortification and Accumulation of Health-Promoting Compounds in Mycorrhizal Cichorium intybus L.

Abstract

The positive impact of arbuscular mycorrhizal symbionts on plant growth and health has been reported for many species, and supports their use as biofertilizers and bioenhancers. Here, the potential role of the arbuscular mycorrhizal symbiont Funneliformis mosseae in the improvement of chicory (Cichorium intybus L.) nutritional value, in terms of nutrient uptake and accumulation of health-promoting compounds, was studied using an in vivo whole-plant system, allowing both plant and fungal tissue collection. Biomass and nutrient distribution were determined in plant and extraradical mycelium, and photosynthetic pigments and fructooligosaccharide concentrations were evaluated in chicory shoots and roots. Zinc shoot concentration of mycorrhizal chicory was significantly increased, as well as the whole-plant Fe uptake, while root Cu concentration was decreased, compared with uninoculated controls. F. mosseae extraradical mycelium accumulated Cu, Zn, Mn, and Fe at high concentrations, compared with those of the host plant tissues, suggesting that it plays a double functional “scavenging-filtering” role, by its ability to balance the uptake of microelements or to limit their translocation depending on plant-soil concentrations. The higher Zn and Fe uptake by mycorrhizal plants was significantly correlated with higher carotenoid, inulin, and fructose levels, suggesting a relationship among the modulation of micronutrient uptake by mycorrhizal symbionts and the biosynthesis of health-promoting molecules by the host. Overall, data from this work may boost the implementation of arbuscular mycorrhizal fungal inoculation aimed at inducing plant biofortification and enhancement of nutritional value of plant-derived food.