“Assessment of the Role of the NOR and NOR-LIKE 1 Genes in Tomato Ripening”
During the internship, we studied the function of NOR (NON-RIPENING) and NOR-LIKE 1 genes and their effect on tomato ripening. Tomatoes are a crucial cash crop to the world economy, however much of the fruit produced never reaches its destination because of rotting. Using manipulated versions of the NOR and NOR-LIKE 1 genes in tomato crops would increase tomato sales significantly, as more tomatoes would reach their destination without spoiling.
The NOR mutation is a naturally occurring loss of function gene mutation that no longer acts as a major ripening regulator as when mutated it blocks all ripening related processes. The NOR-LIKE1 gene shares 72% homology to the NOR gene. To explore the function of the NOR-LIKE 1 gene, an RNAi approach was previously used by others in the lab to downregulate expression. A possible redundant function of these two very similar genes was tested by over expressing (OE) the NOR gene in the NOR-LIKE1 RNAi repression line to see if NOR could recover any of the ripening deficiencies resulting from NOR-LIKE 1 repression. Three transgenic lines for each construct were available in the green house at the start of my internship. In order to identify plants that contain transgenes DNA extractions and PCR using gene specific primers was performed. Plants that had positive PCR amplifications for the transgene were selected and transplanted for further analysis of fruit ripening phenotypes. Downregulation of the NOR-LIKE1 gene results in yellow-orange-fruit that partially ripens suggesting a role of this gene in fruit ripening. Overexpression of the NOR gene in the NOR-LIKE1 RNAi line produced plants that present NOR-LIKE1 plant and fruit phenotypes, suggesting that the NOR gene is not able to complement the NOR-LIKE1 gene and therefore that while both related genes influence ripening, the functions of these two genes are distinct.
This research project taught me many important lessons, not only about research but about work and even life in general. I learned a lot about what research is like as well as molecular techniques used to perform that research. Additionally, we were taught not only lab tools and techniques but also how to make connections between experimental results and the objective of our projects. I also learned about the laboratory environment and how important is interaction with the mentor and other people in a lab in order to perform successful experiments and correct mistakes. Finally, I learned important life lessons about work. This internship was my first job, and it made me realize that hard work is necessary to accomplish anything in the work world.