Methodology and scientific achievements of 2003,

planning for 2004

Participant 4/Rennenberg

Subcontractor 2/Sandermann

Freiburg meets Kranzberg forestExperiences of 2003

Field campaigns 2003

JuneJuly-AugustSeptember

leavesapoplastic solution

xylem/phloem

rootssoilsoil waterrain water

wood

Contribution of work

Participant 4/Rennenberg Subcontractor 2/Sandermann

WP1 WP2 WP2

isotopes (Kris)starch (Kris)sugar (Maria)

ascorbate (Kris)glutathione (Maria)

salicylic acid (Sascha)gene level (Sascha)ACC (GSF)macro arrays (2004)

histochem. analyses (2004)

Links to the other work groups

Participant 4WP1

Participant 4WP2

Subcontractor2

WP2

Antioxidants/injury amplification reactions

Participant 8WP2

antioxidants

Participant 5WP2

Participant 6WP2

Fine-root functionality

Participant 2WP1

Rubisco/PEPC-activitystarch

Participant1Participant7

WP1

TranspirationgH2O

Participant 3Subcontractor 1

AWF extracted in the laboratory after sampling, N2

ascorbate, redox state

leaves N2 ascorbate, glutathione, redox state, salicylic acid, ACC, gene expression

δ13C; Δ18O; δ15N, total C/N;

starch, sugar

xylem Scholander bomb, N2glutathione, ascorbate, redox state

δ13C; Δ18O, δ15N, total C/N, sugar

phloem exudated from bark, N2glutathione, ascorbate, redox state

δ13C; Δ18O, δ15N, total C/N, starch, sugar

wood collected from single twigs ascorbate, redox state

δ13C; Δ18O, δ15N, total C/N, starch

roots digged out, washed,N2ascorbate, redox state,

gene expression

δ13C; Δ18O, δ15N, total C/N, starch, sugar

rainwater collected from a rain barrel, N2δ13C; Δ18O, δ15N, total C/N

soil water will be provided by δ13C; Δ18O, δ15N, total C/N

soil

was collected in different height levels (0,5,10,15,20,25 cm), dried

δ13C, δ15N, total C/N

Objectives (Kris)

δ 13C: assessment of relative activity changes between C-fixing enzymes (Rubisco/PEPC)

δ 13C is dependent from the CO2-concentration in the gaseous phase of the apoplast.

The CO2-concentration is dependent from assimilation and gH2O.

Δ18O: stomatal conductance

WUE: assimilation/transpiration WUEintr: assimilation/gH2O

14N/15N: information about translocation of sugars.

total C/N: C/N changes of the whole plant : seasonal/annual time scale

starch: carbon fixation through carbohydrates/transport

ascorbate: antioxidant status in the whole tree, direct reaction with ROS in the apoplastic solution (hear also Karin)

Few scientific achievements......

1 x O3 2 x O30,00

0,02

0,04

0,06

0,08

0,10

0,12

0,14

0,16

Ascorbate content in the apoplastic washing fluid (sun crown, 16.06.03)

µm

ol/g

fw

reduced Asc total Asc

Objectives (Maria)

Total sugar in:

Leaves Fine roots Phloem Xylem

GSH GSSG Redox status of

glutathione in:

Leaves Fine roots Phloem Xylem

Role of Glutathione

Glutathione-tripeptide

-formed in the leaves-multiple function

Effects: activity and expression of genes

• pool and transport formof reduced S• takes part in regulation/assimilation S

• important antioxidative substance• defense against pathogens, heavy metals, etc.

SOME EFFECTS OF OXIDATIVE STRESS ON THE PHYSIOLOGY OF PLANTS:

Degradation of:ProteinsAmino acidsLipids

Products of photosynthesisdecrease

Respiration increases

Redox status of GSH and Ascorbate and other antioxidants change

Effect on allocation

Glucose in leaves

Glucose in leaves

0

50

100

150

200

250

300

350

400

1xO3 Light 1xO3 Shade 2xO3 Light 2x O3Shade

sp

µmol

/fg

Aug 02

J uly03

Sep 03

Glucose in leaves

0

50

100

150

200

250

300

350

J uly02 J uly03 Sep 03

µmol

/gr fw

1xO3 Light

1xO3 Shade

2xO3 Light

2x O3Shade

Glutathione

Redox status of Glutathione 8/02GSSG/total

0%

10%

20%

30%

40%

50%

60%

70%

80%

Light Shade Fineroots

1xO3

2xO3

Conclusions so far

-Light decrease of sugar

-Increase of GSSG