sucrose metabolism in developing northern red oak ( quercus rubra ) acorns

Sucrose metabolism in developing northern red oak (Quercus rubra)

acorns

Shi-Jean Susana Sung and Paul P. Kormanik

Institute of Tree Root Biology

USDA Forest Service, Athens, GA

Sink Strength (J Warren-Wilson, 1967)

Sink Strength (g d ) = Sink Size (g) x Sink Activity (g g d )

-1

-1-1

Sink size: weight, volume, length, number of sinksSink type: vegetative, reproductive

Sink activity: import of C-14, turgor pressure, growth rate, respiration rate, enzyme activity

SucroseUDP

Glc + Fru Glc + Fru Fru + UDP-Glc

123

Glc-6-P Fru-6-P

ATPADP

Glc-1-P

Glc-6-P

Fru-6-P

Fru-1,6-P2

Pyruvate

PPi

UTP

ATP

ADP

PPi

Pi

456

7

8

7

109

Enzymes

1) Sucrose synthase

2) Acid invertase

3) Neutral invertase

4) UDPglucopyrophosphorylase

5) Fructokinase

6) Glucokinase

7) Phosphoglucoseisomerase

8) Phosphoglucomutase

9) PPi-phosphofructokinase

10) ATP-phosphofructokinase

ATPADP

S.S. Sung et al.

Plant Cell Environ (1994) 17, 419

Time course of Phaseolus vulgaris seed development

S.S. Sung et al.

Plant Cell Environ (1994) 17, 419

Time course of development of a typical Phaseolus vulgaris fruit (one pod plus five seeds)

Northern red oak seed orchard at Flint River Nursery, GAMay 2002

June 7, 2002

6-7 7-11 8-6 9-3 10-10

Outside crownInside crown

undeveloped

July 11, 2002

aborted

July 11, 2002

12 acorns

acorn dropped

Most acorns loose/dropped

June 7, 2002: Acorns branches without leaves

Acorn branches without leaves

Acorn branches without leaves

6-7 7-11 8-6 9-3 10-10

5

10

15

20

25

Dia

me

ter,

mm

June July Aug Sept Oct

2002

Diameter Development ofNorthern Red Oak Acorns

Fruit

Cup

Dry

We

igh

t, g

June July Aug Sept Oct

Dry Weight Development of Northern Red Oak Acorns

2002

FruitPericarpSeedCup

5

4

3

2

1

0

0

20

40

60

80

100

PericarpSeedCup

June July Aug Sept Oct

2002

%

Fin

al

Dry

We

igh

tDry Weight Development of Northern Red Oak Acorns

30

40

50

60

70

80CupPericarp

CotyledonsSeed coat

Mo

istu

re C

on

ten

t, %

June July Aug Sept Oct2002

Moisture Contents of DevelopingNorthern Red Oak Acorns

0

20

40

60

80

100

% F

ruit

Dry

Wei

gh

t

June July Aug Sept Oct

2002

Dry Weight Allocation (%) in DevelopingNorthern Red Oak Acorns

Seed coat

Cotyledons

Pericarp

0

20

40

60

80

100

% S

eed

Dry

Wei

gh

t

June July Aug Sept Oct

2002

Dry Weight Allocation (%) in DevelopingNorthern Red Oak Acorns

Seed coat

Cotyledons

Date June 7 June 21 July 11 June 21 July 11

Tissue Pericarp Pericarp Pericarp Seed Seed

Avg DW, g 0.12 0.28 0.72 0.007 0.071

Avg MC, % 68 69 68 77 79

SS* 24 27 1 30 51UDPG PPiase 4488 4312 3265 938 2667

PPi-PFK 122 95 73 130 32ATP-PFK 68 57 97 16 27FK 64 73 59 46 47

GK 72 88 42 48 20

PGM 1262 1038 843 815 508

PGI 1241 1056 826 1215 508

* Enzyme specific activity: nmol min mg protein-1 -1

Sucrose metabolizing enzyme activities in developing northern red oak acorns

May 2002

July 26, 2002

July 26, 2002