A Tennessee Tech professor said that yellow coat on your car is one of the biological necessities of our world, ensuring plant survival and genetic diversity.
Hannah Kinmonth-Schultz is an assistant professor in Plant Physiological Ecology in Tech’s Biology Department. Kinmonth-Schultz said pollen acts as a vector for sperm to reach female reproductive structures so that a seed can form.
“Plants don’t move,” Kinmonth-Schultz said. “So they have to be able to get their pollen to the female reproductive structures, usually on another plant. And in order for that to happen it’s really kind of by happenstance, by chance. And so in order for that to happen they have to produce a lot, and so it’s only some of the pollen that really kind of gets lucky that lands on the female reproductive structures that finishes the cycle. And so in order for that to happen plants have to increase their odds by producing a whole bunch of pollen.”
Kinmonth-Schultz said the pollen causing allergy problems comes specifically from wind-pollinated plants rather than animal-pollinated varieties. She said pollen carried by animal vectors is heavy and sticky, whereas wind-carried pollen is smaller and easily goes airborne.
“And so pollen ensures that plants are able to reproduce the same way animals can, but they have to do it because they’re not mobile, so they have to do it either with wind or animal vectors and it ensures that there is that genetic mixing so that there continues to be that genetic diversity that allows them to adapt to their environments,” Kinmonth-Schultz said.
Kinmonth-Schultz said a warming climate and increasing day length cue plants to flower and release pollen. She said rising atmospheric carbon dioxide acts as food for the plants, which can impact how fast they develop and cause them to release pollen at different times of the year.
“But a lot of our trees, which are important, like oaks and maples and nut trees, they are wind-pollinated and you’re right, like we want them to hang around,” Kinmonth-Schultz said.
Kinmonth-Schultz said spring is a highly favorable time for reproduction because plants are ramping up photosynthesis and seeds that set now can take advantage of the growing season. She said many essential agricultural crops, including grains and corn, also rely entirely on wind pollination to survive.
“And I guess another thing that is important is so a lot of the showy flowers are not wind-pollinated,” Kinmonth-Schultz said. “They are animal-pollinated, so bees or bats or butterflies or hummingbirds. And so those are not the kinds of pollens that cause us allergens. They are heavier and sticky and so they aren’t the ones that are going to go up into the air and then get into our bodies when we breathe them in.”