Bénard, C.; Bourgaud, F.; Gautier, H. Impact of Temporary Nitrogen Deprivation on Tomato Leaf Phenolics. Int. J. Mol. Sci. 2011, 12, 7971-7981.
Abstract
Reducing the use of pesticides represents a major challenge of modern agriculture. Plants synthesize secondary metabolites such as polyphenols that participate in the resistance to parasites. The aim of this study was to test: (1) the impact of nitrogen deficiency on tomato (Solanum lycopersicum) leaf composition and more particularly on two phenolic molecules (chlorogenic acid and rutin) as well as on the general plant biomass; and (2) whether this effect continued after a return to normal nitrogen nutrition. Our results showed that plants deprived of nitrogen for 10 or 19 days contained higher levels of chlorogenic acid and rutin than control plants. In addition, this difference persisted when the plants were once again cultivated on a nitrogen-rich medium. These findings offer interesting perspectives on the use of a short period of deprivation to modulate the levels of compounds of interest in a plant.
Conclusions
The present work reveals part of the tomato plant strategy when submitted to a temporary nitrogen deprivation. A nitrogen deprivation period of 10 or 19 days induced a persistent effect on the phenolics content in leaves of tomato plants. Indeed we quantified a higher content of phenolics in leaves of tomato plants grown with no nitrogen in comparison to control plants grown with 7 mM NO3 −. Moreover, the content of chlorogenic acid and rutin remained higher in plants that had previously been deprived compared to the control when all these plants were further cultivated on a nitrogen-rich medium for 5 days.
Furthermore, during these experiments, the duration of nitrogen stress (10 to 19 days) engendered a marked reduction in plant biomass production. It would therefore be interesting to test the impact of occasional nitrogen deprivation on plants that have already developed larger leaf area in order to determine whether such nitrogen stresses are sufficient to enhance the defenses of vegetative plant parts without affecting fruit yield.
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