Carotenoids are 40- carbon lipid-soluble terpenoid molecules which are present in most tissues of higher plants. Carotenoids are strong antioxidants that protect the plant from harmful reactive oxygen species (ROS) and protect plastids from photo-oxidation from excess light energy. Carotenoids also play a role in human health. Studies show that carotenoids such as lutein, lycopene, and b-carotene can lower the risk of certain types of cancer and prevent blindness and diseases of the eye. Carotenoids are also a precursor to the hormone abscisic acid (ABA) in plants, which is important in protecting the plant from abiotic stresses (i.e. drought, water stress, etc.). Galpaz et. al (2008) showed that the loss of ABA in developing fruit leads to increased chloroplast division. In this study we wanted to explore this relationship further by comparing the ABA deficient mutant, notabilis (not/not) and two independent transgenic ZDS-RNAi lines, which present a block at zeta-carotene desaturase (ZDS) in the carotenoid biosynthesis pathway and low ABA levels, to wild type (Solanum lycopersicum, cv. Ailsa craig (AC)). ZDS is located upstream of the photoprotecting carotenoids and ABA biosynthesis, whilenot does not affect carotenoid biosynthesis directly and is specific to ABA biosynthesis, therefore physiological changes in these lines are very different from each other and from AC. Our goal was to compare the type and amount of carotenoids, chlorophyll, and hormones produced in each of the three genotypes throughout the stages of fruit development and to see how changes in these biochemical profiles affect the fruit as it proceeds to ripening.
My 10 week experience with the Giovannoni Lab at BTI was very beneficial in a few different ways. After my time here, I feel much more confident in my abilities to work in a lab, conduct research, and apply to graduate schools that I never thought I would have had a chance of getting into before. My mentor was very helpful when I needed guidance, but was also gracious enough to let me work alone when I was comfortable with a protocol so as to help build my confidence in my abilities. I was also able to truly see what it is like to work in a lab environment on a 9-5 basis, and have a much more positive attitude towards doing this in the future. I came into this internship as a full-fledged environmental science major, not very comfortable with, or excited about, molecular biology. However, I honestly have to say that after this summer, I am considering a future career in something more lab-oriented and molecular-based.