Researchers have studied the growth of roots into the soil through a time-lapse video. The research was carried out by a team from Duke University. A team of biologists from Philip Benfey's lab in the varsity set up a camera in germinated rice seed in a clear gel. The camera was installed to take a new picture every 15 minutes to capture the process of germination over several days.
Upon compressing the 100 hours clip into less than a minute, the researchers observed that rice roots use a trick to grow into the soil. They make spiral motions, growing in a helical path.
A study published by Eurekalert suggests that the researchers gained new insights into the reason behind the twirling of plant roots as they grow. They also observed that not all the roots can do the corkscrew dance as they carry HK 1 mutation. The study revealed that the mutant grew twice deeper than normal ones.
The experiments performed in physics professor Daniel Goldman's lab at Georgia Tech suggested that normal spiralling roots were three times more likely to find a hole and grow to the other side. The team planted the normal as well as mutant rice seeds in a dirt mix to observe the obstacles encountered by a root inside the soil. They observed that the mutants had trouble growing deeper,while the normal roots with spiral-growing tips were able to bore deeper.
As per the report, researchers think that the plant hormone auxin is responsible for the growth, which might move around the tip of the roots in a wave-like pattern. However, in roots carrying HK1 mutant has a defect in the way auxin is being carried out the cell to cell. Their hormones get blocked and eventually lose their ability to twirl. A postdoctoral associate in Benfey's lab at Duke named Isaiah Taylor said that the spiral growth of root tips is perhaps a search strategy to find the best path forward.