This summer I finally started my own research project. I spent the summer working in the Caylor Lab in Princeton, helped by Craig Sinkler, a student from Rider University who did an internship in our lab this summer. We planted six large bulbs of Colocasia esculenta that we watered until the plants reached maturity. After about 4 weeks of growth, we stopped watering the plants. Every two days, we sprayed the leaves of half of the plants with isotopically spiked water, while the other half of the plants did not get any water. We collected leaves from each treatment and looked at the spatial distribution of water isotopes in the leaf using the Picarro Induction Module. I then built maps of the leaf isotopes for leaves collected at different times within a 4 week long treatment.
In order to help us interpret the evolution of the spatial patterns of the leaf isotopes, I also started running a water potential experiment in which I leave a leaf dry out under a heat lamp over a period of 10 hours and collect samples every half hour that I run on the WP4C to measure leaf water potential. I have been running the same experiment but spraying the leaf with ultra pure water every hour to look at whether foliar uptake is actually happening in Colocasia esculenta and how it improves water potential. Preliminary results show that foliar uptake is indeed happening!