Rey Cotto is an entomology Ph.D. student working under Professor Ping Wang at Cornell AgriTech. He first met Wang in 2016, while he was an undergraduate at the University of Puerto Rico, Mayagüez, when he had the opportunity to come to the Geneva, New York campus as part of our Summer Research Scholar Program.
Recently, I talked with Rey to learn more about his graduate research, which examines how insects process certain bacterial toxins in the soil and how scientists can use this knowledge to develop crops that are more resistant to pests.
1. What project were you working on as an undergraduate in the Summer Research Scholar program?
In Ping Wang’s lab, I researched DNA and protein sequence variations of a specific Bt-toxin receptor in the cabbage looper midguts from different populations. While working in this research experience I developed more interest in this field for insect pest control and ultimately motivated me to apply to graduate school at Cornell.
Bt-toxins are produced by Bacillus thuringiensis (Bt), a soil-dwelling bacterium, and are used for insect pest control. The midgut is a tissue by which arthropods acquire nutrients. Once Bt-toxins are absorbed in the midgut, the toxins are activated. The activated toxin breaks down the gut, and the insects die of infection and starvation. This toxin can also be used in the production of genetically engineered crops known as Bt-crops. The crops, which contain the toxin, are naturally resistant to a number of specific pests and cause no harm to non-target organisms, including humans, wildlife, and most beneficial insects.
Fast forward five years, and I am now a Ph.D. candidate in the field of entomology at Cornell AgriTech where I am furthering my research to support sustainable crop production worldwide.
2. What is the current focus of your research at Cornell AgriTech?
The Wang Laboratory studies the biochemical and molecular basis of insect midgut physiology, as well as how the midgut interacts with host plants and microbial pathogens. My own research focuses on understanding the evolution of insect resistance to Bt-toxins in Bt-crops. Through this work, I hope to acquire knowledge to help develop novel pest management technologies.
More specifically, I work on the molecular mechanism of resistance of the three most widely used Bt-toxins. We use the cabbage looper pest as our model organism to investigate and identify novel midgut receptors involved in Bt-toxin toxicity, to then understand how we can use these factors for controlling insect pests.
3. How could your work help solve critical problems that growers face?
So far, Bt-resistance has been reported in five countries and in seven populations of their major agricultural pests. Additionally, this resistance is tied to each of the nine Cry toxins produced by widely-grown Bt crops. Through our research, we hope to better understand how insects have developed resistance to these Bt-toxins.
It is important to understand this resistance because Bt-crops across the world contribute significantly to food security, sustainability and climate change mitigation. These crops keep food on the table by allowing farmers everywhere to successfully manage pests in a sustainable way. Genetically engineered crops with Bt genes have been used for commercialized cultivation in maize, cotton, soybean, rice, potato, eggplant, tomato and sugarcane.
