Gene Lester, Ph.D.U.S.D.A.

Agricultural Research ServiceBeltsville, MD

‘Samish’ ‘Lazio’

Dry Weight20DarkLight

15

%

10

5

0

Days Storage at 4oC

0 2 4 6 8 100

Loss of Turger10

Loss of Turger

o

0

ne fr

om 0

-10

es d

eclin -20

Deg

ree

40

-30Dark Light

-50

-40

Days Storage at 4oC

0 2 4 6 8 1050

Plant &Human Benefits of:Plant &Human Benefits of:Vitamin C (ascorbic acid) ( )

Plant scavenges reactivePlant – scavenges reactive oxygen species in Ps-II

Human – supports the immune system & scavenges ROSsystem & scavenges ROS

Ascorbic Acid10

Ascorbic Acid

8

DarkLight

ry w

t.)

6

g/ 1

00g

d

4

(mg

2

0

Days Storage at 4oC

0 2 4 6 8 100

Pant & Human Benefits of:Pant & Human Benefits of:Vitamin B9 (Folate) ( )

Plant – remethylates RuBP in Calvin CycleCalvin Cycle

Human – remethylateshomocysteine to methioninehomocysteine to methionine

50

Folic Acid - Vit. B9

40 Dark

wt.) 30

Light

ug/g

dry

20(

10

0

Days Storage at 4oC

0 2 4 6 8 100

Plant & Human Benefits of:Plant & Human Benefits of:Vitamin K1 (phylloquinone)Vitamin K1 (phylloquinone)

Plant – electron carrier in Ps-I

Human – blood vessels, diabetes & bone health.

60

Phylloquinone - vit. K50 Dark

Light

y w

t.)

40

ug/ g

dry 30

(u

10

20

0

10

DaysStorage at 4oC

0 2 4 6 8 100

Plant & Human Benefits of:Plant & Human Benefits of:CarotenoidsCarotenoids

Plants– light electron collector in Ps-IIPs II

Humans- age related blindness & skin cancerskin cancer

50

Lutein & Zeaxanthin40

DarkLight

dry

wt.)

30

g/ 1

00g

d

20

(mg

10

0

Days Storage at 4oC

0 2 4 6 8 100

Plant & Human Benefits of:Plant & Human Benefits of:Vitamin EVitamin E

(alpha tocopherol)

Plants electron transfer in Ps IIPlants – electron transfer in Ps-II

Human– powerful antioxidant

40

α-tocopherol - Vit. E

30

DarkLight

dry

wt.)

30

g/ 1

00g

d

20

(mg

10

0

Days Storage at 4oC

0 2 4 6 8 100

Total Antioxidants

20Dark Total Antioxidants

wt.) 15

Light

./g d

ry w

ox e

quiv

.

10

(trol

o

5

0

Days Storage at 4oC

0 2 4 6 8 100

ConclusionsExposure to continuous light1. increases vitamin and antioxidant concentrations.2. promotes leaf wilting in flat-leaf cultivars.p g

Exposure to continuous darkExposure to continuous dark1. decreases vitamin and antioxidant concentrations.concentrations.2. maintains leaf turgidity.