Red leaf plants have aroused intriguing scientific debates over the last few years, not only to investigate their ecological role but especially to assess and improve their nutritional value as food plants. In most species, red colour in leaves is due to the accumulation of anthocyanins, the red pigment known for its antioxidant properties and therefore considered as an additional high nutritional value of red-leaf food plants. New research projects aimed at producing high quality food plants are supported by both Italian (ASI) and European Space Agencies (ESA) because plants represent a key element in bioregenerative life support systems, such as MELiSSA (Micro-Ecological Life Support System Alternative), not only for the water/air/waste recycling but also for the production of high quality plant food. Increasing attention is paid at such features in the selection of crop species aimed to become fresh food for astronauts in Space environment. Previous studies indicate that anthocyanins carry out several functions in plants, representing the nature’s Swiss army knife. A role in photoprotection is widely accepted, although this hypothesis is not always applicable and several exceptions are mostly explained ecologically by considering plant/herbivores interactions or various stress responses (1, 2). From a chemical and physical point of view, these watersoluble pigments, generally located within cellular vacuoles of epidermal and/or external mesophyll cells (Fig. 1), strongly absorb light in ultraviolet, blue and green wavelengths. The hypothesis was that highenergy wavelengths stimulate anthocyanins production to protect photosynthetic tissues, thus chloroplasts, from energizing wavelengths that commonly induce inhibition phenomena of the photosynthetic apparatus. Interestingly, green crop species grown under different light spectra are reported to modulate the synthesis of various compounds, including anthocyanins (3, 4). The general aim of our work was to apply the LED-based plant cultivation systems to maximise nutritional value of red-leaf plant food. More specifically, we grew green and red cultivars of Atriplex hortensis L. under different combination of light wavelengths (Fig. 2) to evaluate whether and how leaf anthocyanins content varies depending on light spectra. Our purpose was to understand plant’s response to different light wavelengths, especially in this valuable microgreens species intended for human diet. Our results showed that there is an increase in the foliar anthocyanins amount related to the amount of blue light within the incident light spectrum, especially in red leaf cultivar. Moreover, the combination of red and blue wavelengths stimulates biomass production and photochemical efficiency in both varieties of Atriplex hortensis L. These results provide useful informations to improve quality of plant food, without neglecting plant productivity, by using specific light spectra. Considering that anthocyanins content is significantly influenced by light quality, red leaf plants grown with adjustable lighting systems represent a promising biological system for high quality food production.

Light quality enhances anthocyanins modulation in red and green cultivars of Atriplex hortensis L.

IZZO, LUIGI;Arena C.;De Micco V;Aronne G.
2017

Abstract

Red leaf plants have aroused intriguing scientific debates over the last few years, not only to investigate their ecological role but especially to assess and improve their nutritional value as food plants. In most species, red colour in leaves is due to the accumulation of anthocyanins, the red pigment known for its antioxidant properties and therefore considered as an additional high nutritional value of red-leaf food plants. New research projects aimed at producing high quality food plants are supported by both Italian (ASI) and European Space Agencies (ESA) because plants represent a key element in bioregenerative life support systems, such as MELiSSA (Micro-Ecological Life Support System Alternative), not only for the water/air/waste recycling but also for the production of high quality plant food. Increasing attention is paid at such features in the selection of crop species aimed to become fresh food for astronauts in Space environment. Previous studies indicate that anthocyanins carry out several functions in plants, representing the nature’s Swiss army knife. A role in photoprotection is widely accepted, although this hypothesis is not always applicable and several exceptions are mostly explained ecologically by considering plant/herbivores interactions or various stress responses (1, 2). From a chemical and physical point of view, these watersoluble pigments, generally located within cellular vacuoles of epidermal and/or external mesophyll cells (Fig. 1), strongly absorb light in ultraviolet, blue and green wavelengths. The hypothesis was that highenergy wavelengths stimulate anthocyanins production to protect photosynthetic tissues, thus chloroplasts, from energizing wavelengths that commonly induce inhibition phenomena of the photosynthetic apparatus. Interestingly, green crop species grown under different light spectra are reported to modulate the synthesis of various compounds, including anthocyanins (3, 4). The general aim of our work was to apply the LED-based plant cultivation systems to maximise nutritional value of red-leaf plant food. More specifically, we grew green and red cultivars of Atriplex hortensis L. under different combination of light wavelengths (Fig. 2) to evaluate whether and how leaf anthocyanins content varies depending on light spectra. Our purpose was to understand plant’s response to different light wavelengths, especially in this valuable microgreens species intended for human diet. Our results showed that there is an increase in the foliar anthocyanins amount related to the amount of blue light within the incident light spectrum, especially in red leaf cultivar. Moreover, the combination of red and blue wavelengths stimulates biomass production and photochemical efficiency in both varieties of Atriplex hortensis L. These results provide useful informations to improve quality of plant food, without neglecting plant productivity, by using specific light spectra. Considering that anthocyanins content is significantly influenced by light quality, red leaf plants grown with adjustable lighting systems represent a promising biological system for high quality food production.
978-88-85915-21-3
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11588/752421
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