1. How Space constraints can trigger positive outcomes
UNIVERSITY OF NAPLES FEDERICO II
DEPT. AGRICULTURAL AND FOOD SCIENCES
Does ionizing radiation influence nutritional value of fruits in dwarf tomato?
How Space constraints can trigger positive outcomes
De Micco V., Aronne G., De Pascale S., Paradiso R., Vitaglione P., Arena C.

2. Space constraints Stress conditions Radiation Gravity Genetics
Structure and function
Physiology and biochemistry

3. Plants versus animals
Arena et al Acta astronautica 104: 419–431
De Micco et. Al Radiat Environ Biophys 50: 1-19

4. Aims Tomato: candidate species for BLSSs
To evaluate the effect of different X-rays doses on fruit traits of
Solanum lycopersicum L. ‘Microtom’ plants
irradiated at different phases of the life cycle
Tomato: candidate species for BLSSs
FOOD as countermeasure
Foods derived from plants are rich in antioxidants which
decrease or prevent the oxidation of other substances
Candidate cultvar: Solanum lycopersicum L. ‘Microtom’
Compact size
Short production cycle
High yield
Good nutritional value of the fruits

5. Phenological phases (I, II, III, IV IR)
Experimental design
X-rays doses
0 Gy (control)
1 Gy
0.3 Gy
10 Gy
50 Gy
100 Gy
Dose rate
1 Gy/min
Phenological phases (I, II, III, IV IR)

6. Analyses Fruit development Anatomical traits Nutritional traits
Reproductive phenology (Number of blossoms, flowers and fruits)
Size of fruits
Fruit development
Resin embedding and tissue thin sectioning
Light and fluorescence microscopy
Digital Image Analysis
Anatomical traits
Carotenoids
Phenolic compounds
Weights
Sugar content
Nutritional traits

7. Completion of the life cycle
I IR
II IR
IV IR
III IR
Formed fruits after IR do not show differences in size but are characterised by lower fresh and dry weight at high X-rays doses when irradiated at early stages of development (I, II)

8. Reproductive phenology
Number of ovaries
Number of fruits

9. Fruit anatomy
Anatomical responses are dependent on dose and phenological phase at irradiation
Radiation-induced increased thickness of sub-epidermal layers rich in phenolics
III IR similar to II
IV IR: n.s

10. Autofluorescence of phenolics
0.3 10
100
Fluorescence due to phenolics increases according to the stage of development at the time of irradiation and according to the dose

11. Carotenoids and phenolics

12. Conclusions
Radioresistence is strictly dependent on the dose and the phenological phase at the time of irradiation
Very high doses in peculiar stages of plant development can be responsible for reproductive failure
X-rays generally induce either an increase or decrease in cartenoids depending on single compounds
Apart from a few compounds, X-rays induce an increase in phenolic compounds
The results strengthen the hypothesis
Can fresh tomatoes produced in Space help maintain a good state of health in astronauts thanks to the antioxidant components (increased by the exposure to radiation) which play a protective role on human organism?

13. General perspective Aims
How to make more from less or from too much
How to transform a constraint into an opportunity

14. Many thanks!