A juicy burger stacked with the works, a light, fresh salad, or a late night pizza delivery. Besides being common meals for college students, what do these foods have in common? All of them can be made with tomatoes. When people think about Kansas agriculture, tomatoes aren’t usually the first crop that comes to mind, but for two researchers at Kansas State University, that is exactly what they think of.

     Horticulture and natural resources faculty members, Sunghun Park and C.B. Rajashekar, have been studying tomatoes for most of their respective careers.

     In a state known for conventional row crops and wheat, Park prefers to work with tomatoes.

     “Tomatoes are the best crop for sequencing,” Park says. “The entire tomato genome has already been sequenced, so it’s easier to research.”

     Sequencing is the precise order of nucleotides that are in a DNA molecule. Park says he also likes that tomatoes are a popular consumer product. From ketchup to pizzas, tomatoes can be seen across U.S. kitchen tables.

Tomatoes and Calcium

     Park has been doing research on tomatoes for 20 years. His first project consisted of increasing calcium in tomatoes to prevent osteoporosis, a weakening of the bones in humans caused by low calcium. By increasing calcium in tomatoes, it helps osteoporosis bones, Park says. He discovered that increasing SCAX1, a calcium transporter, causes the increase in calcium levels in tomatoes. Research is still being conducted, but preliminary tests show a correlation in increased calcium in tomatoes and decreases in osteoporosis.

      Presently, Park is researching blossom-end rot on tomatoes, which is caused by calcium deficiency. Blossom-end rot is a water-soaked spot at the blossom end of a tomato and can cause a significant economic impact on tomato producers and the industry, which is an estimated $2.5 billion in the U.S. each year, according to data from the USDA.

     His most important conclusion was genetically engineering a higher calcium tomato. Through this, he discovered that having a lack of calcium content in the fruit causes the blossom-end rot.

     “One hundred percent of tomatoes get blossom-end rot. If you increase the calcium, the blossom-end rot will decrease,” Park says.

Powercat Tomatoes

     Another study Park worked on was developing a purple tomato. Park says his greatest achievement was working on the first genetically engineered tomato, which happened to be purple. During his research, he increased the anthocyanin phytochemical nutrients, which can help with fighting against diseases and cancers. Anthocyanin is a water-soluble pigment that can change the color of an item to either red, purple or blue.

     Without changing the taste, Park and his colleagues on the project were able to increase this cancer-fighting nutrient. The end result of increasing the anthocyanin, was a purple tomato.

     “My most important accomplishment in tomato research was the first developed genetically engineered tomato, which reliably mimics the symptoms of blossom-end rot,” Park says.

Light and Tomatoes

     Rajashekar also has a past with tomatoes. He has worked on increasing the mineral nutrients of tomatoes by comparing tomatoes being grown in a high tunnel to those grown in the open field. The goal was to see which method was better for growing more nutritional tomatoes. Rajashekar found that the high tunnel produced a tomato with a higher nutritional value than the open field.

     Rajashekar is currently researching how light influences tomato quality at the K-State Olathe campus.

     Across the country tomatoes sell well, which is what makes them so interesting to Rajashekar. Similar to Park, he also likes that tomatoes are popular among consumers. One reason Rajashekar believes tomatoes are such great sellers is because they have health benefits. Tomatoes reduce the risk of heart disease and different cancers along with being a great source of vitamin C, potassium, folate and vitamin K, Rajashekar says.

     The research has contributed to the rest of the literature on tomatoes because Park and Rajashekar improved the tomato in a positive way by making it better for human consumption.

     “Tomatoes do very well in warm growing conditions like Kansas in the summer,” Rajashekar says. “There is no reason not to grow tomatoes in Kansas.”