Watching a plant grow and develop roots can be a long and tiresome process. But seeing plant development, as it unfolds, can expose to what happens to a genetically modified organism and how certain plant gene modifications can make plants do certain things. Robotic cameras and computerized motion control systems are making this process easier.
Plant physiology researchers at the Univ. of Wisconsin-Madison designed an automated image acquisition system, using robotic camera CCD imagers and XYZ vertical robotic gantry system "PhytoBot", to create time-lapse movies of plant growth in action. The system collects images of the plants that have been genetically altered with the intention of understanding of how the genetic manipulation affects their growth and development.
Researchers placed plant samples in an LED-illuminated 6xx6 grid of Petri plates, mounted on a vertical tubular aluminum frame, to conduct 36 experiments in parallel. IntelLiDrives’ robotically controlled vertical XYZ gantry moves a pair of cameras between samples of growing plants. An array of infrared light-emitting diodes were mounted behind the fixture to provide illumination for the imaging system.
The XYZ gantry consists of computer-controlled linear actuators, each integrating brushless linear servo motor with high resolution linear encoder, moves the CCD cameras over a 1-m by 1-m area with a positioning resolution of 10 micrometers. Additional linear axis allows change of camera's field of view to acquire well focused images of seedlings in Petri plates. Robotic camera snaps pictures every 30 secs, capturing the curling, twisting motion of germinating seeds putting out new roots.
After capture, the images were analyzed to determine cellular growth rates in the root as well as the angle and curvature of the root tip. Computer vision algorithms studied the camera's time-lapse videos and measured the sizes of seeds, plants' cellular growth rates, the angle and curvature of the roots and more.
The XYZ robot with the computer vision system gave researchers the ability to automate the plant growth time-lapse image acquisition and processing and to increase throughput of experiments to track the plants growth and development. Researchers were able to quickly find the genes that control plant's root growth and have fundamental importance to crop improvement. The system helps lay the foundation for discoveries that will help improve plants for human purposes.