Effects of LEDs on Photosynthesis andSecondary Metabolites in Roses,

Chrysanthemums, and Campanulas

1 Department of Chemical Engineering, Biotechnology and Environmental Technology,University of Southern Denmark, Odense, Denmark

2 Department of Agriculture and Ecology, Crop Science, University of Copenhagen,Taastrup, Denmark

3 Department of Food Science, Aarhus University, Aarslev, Denmark

Theoharis Ouzounis1, Xavier Fretté1, Eva Rosenqvist2, Carl Otto Ottosen3

Concept

Objectives

Results

Conclusions

Presentation Outline

Concept

Objectives

To characterize the effect of LED lighting

in horticultural ornamentals grown ingreenhouse facilities

on the photosynthetic characteristics and thephysiological mechanisms of selected plantspecies

on secondary metabolites which play a crucialrole in the biochemical defense of the plant

Concept

Plant material

Roses (Rosa hybrida ‘Scarlet’)

Chrysanthemums (Chrysanthemum morifolium ‘Coral

Charm’)

Campanulas (Campanula portenschlagiana ‘BluOne’)

The plants were grown to flowering (except chrysanthemums) andplant growth was recorded at the end of the experimentConce

pt

(1) 40% Blue 60% Red (2) 20% Blue 80% Red (3) 100% Red (4) 100% Whiteor Control (C)

Greenhouse Setup

LED array yielding approximately 200 µmol m-2s-1 for 16 hours per day

The temperature in the greenhouse compartments was set to 24 oC and 18 oCduring the day and night, respectively

Concept

Photosynthetic measurements

Open gas exchange systemsCIRAS-2. Real-time measurementsof CO2 uptake, transpiration,stomatal conductance (gs), andintercellular CO2

Fresh and dry weight of the stemsand leaves, leaf area, and plantheight

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Chemical analysis

Leaf samples are taken randomly forlater analysis by HPLC/LCMS

Samples were ground with liquidnitrogen and 80% MeOH was used forextraction

Separations with a Zorbax EclipseXDB-C18 column (5μm, 150 X 4.6 mm;Agilent)

Phenolic acids and flavonoids will bequantified in extracts by HPLC andLCMS at 320 nm and 360 nm,respectively

Concept

Growth parameters

ROSESTotal FW and DW: Highest percentage in the 100%R

(up to 15% increase compared the Control)Leaf area: 40%B/60%R, 20%B/80%R, and 100%R

treatments (up to 30% higher than the Control)Plant height: Not affectedNumber of color buds: Not affected

Pure RED demonstratedmorphological abnormalities

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Growth parameters

CHRYSANTHEMUMSTotal FW, DW, and Leaf Area: Higher for both

BLUE/RED treatments with NO significant differenceamong treatmentsPlant height: Not really affected

CAMPANULASTotal FW and DW: NO difference among treatmentsLeaf Area: Higher for 20%B/80%R and the Control with

NO significant difference between themPlant height: Not affected

Concept

Net photosynthesis and stomatalconductance

Pn: NO effect among treatments *Same for all 3 plants

gs: Higher for 40%B/60%R and 20%B/80%R *Same for all 3 plants

PAR (mol m-2 s-1)

0 100 200 300 400 500

Pn

(mm

ol

m-2

s-1

)

-10

-5

0

5

10

15

20

25Chrysanthemums40% B / 60% R

20% B / 80% R100%RControl

PAR (mol m-2

s-1

)

0 100 200 300 400 500

gs

(mm

ol

m-2

s-1

)

100

150

200

250

300

350

400

450

500Chrysanthemums40% B / 60% R

20% B / 80% R100%R

Control

Concept

Roses – HPLC and LCMS

40%B/60%R: Highestamount of phenolicacids and flavonoids

Same forneochlorogenic acid,quercetin, and others

Treatments

40%B / 60%R 20%B / 80%R 100%R C

PeakAre

a

0

500

1000

1500

2000

2500

3000

3500Roses - Chlorogenic acid

a

ab

b b

Treatments

40%B / 60%R 20%B / 80%R 100%R C

PeakAre

a

0

500

1000

1500

2000

2500Roses - Rutin

a

b

bb

64%82% 81%

68% 76% 75%

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Chrysanthemum – HPLC and LCMS

40%B/60%R and20%B/80%R: Highestamount of flavonoidsNO Phenolics detected

Same for kaempferolglucoside, apigeninglucuronide, and others

Treatments

40%B / 60%R 20%B / 80%R 100%R C

Peak

Are

a

0

100

200

300

400

500

600Chrysanthemums - Apigenin derivativea

ab

b

ab

Treatments

40%B / 60%R 20%B / 80%R 100%R C

PeakAre

a

0

100

200

300

400

500Chrysanthemums - Acacetina

ab

b

b

22%48% 24%

19%

64% 66%Concept

Campanulas – HPLC and LCMS

40%B/60%R and20%B/80%R: Highestamount of phenolicacids and flavonoids

Same forneochlorogenic acid,rutin, and others

Treatments

40%B / 60%R 20%B / 80%R 100%R C

PeakAre

a

0

500

1000

1500

2000

2500

3000

3500

4000Campanulas - Flavonoid unknown

a

b

b

b

Treatments

40%B / 60%R 20%B / 80%R 100%R C

Peak

Are

a

0

2000

4000

6000

8000

10000

12000Campanulas - Chlorogenic acid

a

ab

b

a

41%

66% 53%

54%

3%15%Conce

pt

Conclusions

The combination of RED and BLUE LED lighting has a positiveeffect on growth and development of roses, chrysanthemumand campanulas

Pure RED light increases total fresh and dry weight BUTdemonstrates the most extensive abnormalities

BLUE/RED lighting treatment seem to have no significanteffect on photosynthesis

Stomatal conductance increases with increasing amount ofBLUE light

The amount of secondary metabolites increases withadditional of BLUE light

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Acknowledgements

Dr Xavier Fretté – University of Southern Denmark

Dr Carl Otto Ottosen – University of Aarhus

Dr Eva Rosenqvist – University of Copenhagen

University of Southern Denmark

Fionia Lighting

EUDP

GreenGrowing ERDF Project

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Ευχαριστώ για την προσοχή σαςTak for jeres opmærksomhedThank you for your attention

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