(Radio Iowa) – An Iowa State University horticulture professor is trying to find out how some plants are able to endure cold winter temperatures and start growing again in the spring. Professor Rajeev Arora says research is showing there’s not one single factor involved the hardening of plants to the cold. “Freezing tolerance or the acquiring of freezing tolerance is not a single factor phenomenon. In other words, several things are changing, and logistically they work together to put the plant in the hardest state,” he says. Arora says one thing he’s studied is a protein called dehydrin, which helps keep plants from losing water in a process called desiccation.”What happens is that when the ice forms inside these tissues, it is never inside the cells, but outside the cells between the cells,” he says.

Arora says ice in the cells causes plants to loose all their water, which leads to their deaths. “It is the desiccation part of the stress that plant actually ultimately succumbs to and gets injured. It is not so much the cold itself, but the desiccating effect of the freezing is what kills the plant,” Arora says. “And so these dehydrants, they prevent that desiccation or do not let all the water to be pulled out, maintain some hydration so that cells can survive.” Arora says he’s also studying the way some plants roll up their leaves to help them survive the cold in what is called “thermonasty.”

He says there’s no one clear process for plants to survive. “Many, many genes are involved, it’s not just one or two, and those have to collaboratively together also. So, it becomes very complicated,” Arora says, “these things have limits.” Arora says there has been some breeding of plants to better survive the cold, and he hopes his research will lead to more information on how to do just that.