Watching plants grow has never been this exciting

It’s hard to take a picture of something that’s always moving—just ask anyone who’s had to photograph a child. Now, one team of researchers has solved the problem on a tiny scale, with a program that lets microscopes automatically track objects invisible to the human eye. Normally, recording something like a growing plant root would mean days of constant adjustments to a microscope. But with their program, researchers were able to watch the cells in root tips of plants (Arabidopsis thaliana) growing and splitting in 3D over the course of days, they report this month on the preprint server bioRxiv. That required some special equipment: a microscope that uses lasers and fluorescent lights to piece together 3D images, a special lighting system to keep the plants healthy during their longer-than-usual time in the spotlight, and a microscope setup flipped entirely on its side so the plants could grow upright instead of growing horizontally along a slide. The team even placed the plants within a rotating plate to study how gravity changes root growth, which could one day help scientists understand the best ways to grow plants in space. To show their program’s promise beyond plant roots, the researchers also used it with a different microscope to watch groups of cells move around in growing zebrafish (Danio rerio) embryos. And because they released their program for free, other scientists can use it to make videos of just about anything that moves.