Impact of pre-irradiation of lettuce seeds on the effect of space-related low dose radiation-induced changes on crop growth and nutritional value
Introduction
This topic is written for a student of the University of Naples, Sara Defrancesco, who is in her final year of her PhD on the use of plants as food for astronauts in long term space exploration. In the framework of the MELiSSA space research program, of which SCK CEN is part, Sara wants to join our group for a long term low dose irradiation experiment. She works on two varieties of lettuce (one green variety and one red variety with is rich in additional antioxidants) and has seeds of these plants that have previously been exposed to a high dose of radiation. The working hypothesis is that pre-irradiation of the lettuce seeds hardens (primes) the plants to space radiation resulting in a changed growth, photosynthesis as well as nutritional value and that this priming signature is molecular in nature. Sara would bring her own plant material as well as has her own budget for this internship.
Objectives & learning goals:
- setting up a long term irradiation experiment and following growth and photosynthesis: plants will be germinated in our growth chambers and after germination transferred to the LNK facility in which they will be exposed to 12-125 µGy/h (dose rates resembling space flight conditions) until harvest (50 days). Growth and photosynthesis will be followed up non-destructively (with pictures and handheld devices) on a routine basis until harvest.
- measuring molecular markers in a non-molecular model species: To this end Sara will learn how to develop primers of genes of interest to study the impact of radiation on lettuce, isolation of RNA from lettuce leaves and convert this to cDNA. The response of the genes of interest will be measured by RT-PCR and compared to the control samples
- After harvest additional nutritional related parameters (protein, sugar, starch, lipids) will be measured
Finally, data will be compiled in a finishing report that will be included as part of her PhD mansucript and ideally is ready to send out as a scientific paper.