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Sequential light programs shape kale (Brassica napus) sprout appearance and alter metabolic and nutrient content.

Carvalho SD, Folta KM - Hortic Res (2014)

Bottom Line: Different light wavelengths have specific effects on plant growth and development.Sequential treatments of darkness, blue light, red light and far-red light were applied throughout sprout development to alter final product quality.These results indicate that sequential treatment with narrow-bandwidth light may be used to affect key economically important traits in high-value crops.

View Article: PubMed Central - PubMed

Affiliation: Horticultural Sciences Department, University of Florida , Gainesville, FL, USA ; Plant Molecular and Cellular Biology Program, University of Florida , Gainesville, FL, USA.

ABSTRACT
Different light wavelengths have specific effects on plant growth and development. Narrow-bandwidth light-emitting diode (LED) lighting may be used to directionally manipulate size, color and metabolites in high-value fruits and vegetables. In this report, Red Russian kale (Brassica napus) seedlings were grown under specific light conditions and analyzed for photomorphogenic responses, pigment accumulation and nutraceutical content. The results showed that this genotype responds predictably to darkness, blue and red light, with suppression of hypocotyl elongation, development of pigments and changes in specific metabolites. However, these seedlings were relatively hypersensitive to far-red light, leading to uncharacteristically short hypocotyls and high pigment accumulation, even after growth under very low fluence rates (<1 μmol m(-2) s(-1)). General antioxidant levels and aliphatic glucosinolates are elevated by far-red light treatments. Sequential treatments of darkness, blue light, red light and far-red light were applied throughout sprout development to alter final product quality. These results indicate that sequential treatment with narrow-bandwidth light may be used to affect key economically important traits in high-value crops.

No MeSH data available.


Related in: MedlinePlus

Chlorophyll levels in 4-day-old Red Russian kale seedlings under selective light conditions. (a) Chlorophyll content after 4 days of exposure to white, far-red, red or blue light with the indicated fluence rates; (b) 1 day of darkness and 3 days of light; (c) 2 days of darkness and 2 days of light; (d) 3 days of darkness and 1 day of light. Results represent the average of three independent experiments. Means±s.e. s.e., standard error.
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fig4: Chlorophyll levels in 4-day-old Red Russian kale seedlings under selective light conditions. (a) Chlorophyll content after 4 days of exposure to white, far-red, red or blue light with the indicated fluence rates; (b) 1 day of darkness and 3 days of light; (c) 2 days of darkness and 2 days of light; (d) 3 days of darkness and 1 day of light. Results represent the average of three independent experiments. Means±s.e. s.e., standard error.

Mentions: The combination of different treatments of altered darkness/light periods and/or different light wavelengths and fluence rates not only represses stem elongation to different extents but also promotes additional different phenotypic behaviors (Figure 1). The typical seedling response to light is seen in all four conditions tested, but appears to be stronger under 96 h of light (Figure 1a), with seedlings exhibiting the most cotyledon expansion, and all appearing greener compared to other time points. In addition, generally, higher fluence rates promote darker colors, independently of the wavelength, whereas lower fluence rates result in greener seedlings. These observations suggested that kale seedlings were accumulating different pigments, namely, anthocyanins and chlorophyll, hallmarks of photomorphogenic development. Having in mind consumer-desired colors and potential nutraceutical content, it is important to understand the parameters of pigmentation upon specific light conditions. Therefore, seedlings were grown as described in Figure 1 and anthocyanins and chlorophyll were extracted and measured. The quantitative results from three independent trials of 18 seedlings are shown in Figures 3 and 4. In all cases, the pigments increased with fluence rate, as expected. Anthocyanins accumulated to similar levels under white, red and blue light, but reached much higher levels under the exposure of any fluence rate of far-red light (Figure 3). Chlorophyll accumulated to approximately the same levels in each seedling set (Figure 4). The exception was that accumulation in red light was higher at 25 μmol m−2 s−1 than at an intermediate rate in any other light quality (Figure 4).


Sequential light programs shape kale (Brassica napus) sprout appearance and alter metabolic and nutrient content.

Carvalho SD, Folta KM - Hortic Res (2014)

Chlorophyll levels in 4-day-old Red Russian kale seedlings under selective light conditions. (a) Chlorophyll content after 4 days of exposure to white, far-red, red or blue light with the indicated fluence rates; (b) 1 day of darkness and 3 days of light; (c) 2 days of darkness and 2 days of light; (d) 3 days of darkness and 1 day of light. Results represent the average of three independent experiments. Means±s.e. s.e., standard error.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591675&req=5

fig4: Chlorophyll levels in 4-day-old Red Russian kale seedlings under selective light conditions. (a) Chlorophyll content after 4 days of exposure to white, far-red, red or blue light with the indicated fluence rates; (b) 1 day of darkness and 3 days of light; (c) 2 days of darkness and 2 days of light; (d) 3 days of darkness and 1 day of light. Results represent the average of three independent experiments. Means±s.e. s.e., standard error.
Mentions: The combination of different treatments of altered darkness/light periods and/or different light wavelengths and fluence rates not only represses stem elongation to different extents but also promotes additional different phenotypic behaviors (Figure 1). The typical seedling response to light is seen in all four conditions tested, but appears to be stronger under 96 h of light (Figure 1a), with seedlings exhibiting the most cotyledon expansion, and all appearing greener compared to other time points. In addition, generally, higher fluence rates promote darker colors, independently of the wavelength, whereas lower fluence rates result in greener seedlings. These observations suggested that kale seedlings were accumulating different pigments, namely, anthocyanins and chlorophyll, hallmarks of photomorphogenic development. Having in mind consumer-desired colors and potential nutraceutical content, it is important to understand the parameters of pigmentation upon specific light conditions. Therefore, seedlings were grown as described in Figure 1 and anthocyanins and chlorophyll were extracted and measured. The quantitative results from three independent trials of 18 seedlings are shown in Figures 3 and 4. In all cases, the pigments increased with fluence rate, as expected. Anthocyanins accumulated to similar levels under white, red and blue light, but reached much higher levels under the exposure of any fluence rate of far-red light (Figure 3). Chlorophyll accumulated to approximately the same levels in each seedling set (Figure 4). The exception was that accumulation in red light was higher at 25 μmol m−2 s−1 than at an intermediate rate in any other light quality (Figure 4).

Bottom Line: Different light wavelengths have specific effects on plant growth and development.Sequential treatments of darkness, blue light, red light and far-red light were applied throughout sprout development to alter final product quality.These results indicate that sequential treatment with narrow-bandwidth light may be used to affect key economically important traits in high-value crops.

View Article: PubMed Central - PubMed

Affiliation: Horticultural Sciences Department, University of Florida , Gainesville, FL, USA ; Plant Molecular and Cellular Biology Program, University of Florida , Gainesville, FL, USA.

ABSTRACT
Different light wavelengths have specific effects on plant growth and development. Narrow-bandwidth light-emitting diode (LED) lighting may be used to directionally manipulate size, color and metabolites in high-value fruits and vegetables. In this report, Red Russian kale (Brassica napus) seedlings were grown under specific light conditions and analyzed for photomorphogenic responses, pigment accumulation and nutraceutical content. The results showed that this genotype responds predictably to darkness, blue and red light, with suppression of hypocotyl elongation, development of pigments and changes in specific metabolites. However, these seedlings were relatively hypersensitive to far-red light, leading to uncharacteristically short hypocotyls and high pigment accumulation, even after growth under very low fluence rates (<1 μmol m(-2) s(-1)). General antioxidant levels and aliphatic glucosinolates are elevated by far-red light treatments. Sequential treatments of darkness, blue light, red light and far-red light were applied throughout sprout development to alter final product quality. These results indicate that sequential treatment with narrow-bandwidth light may be used to affect key economically important traits in high-value crops.

No MeSH data available.


Related in: MedlinePlus