Protocol for producing three-dimensional infrared video of freezing in plants

Authors: LIVINGSTON, DAVID; Tuong, Tan; HOFFMAN, MARK - NORTH CAROLINA STATE UNIVERSITY; FERNANDEZ, GINA - NORTH CAROLINA STATE UNIVERSITY

Submitted to: Journal of Visualized Experiments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2018
Publication Date: 4/16/2018
Citation: Livingston, D.P., Tuong, T.D., Hoffman, M., Fernandez, G. 2018. Protocol for producing three-dimensional infrared video of freezing in plants. Journal of Visualized Experiments. 139:e58025. https://doi.org/10.3791/58025.
DOI: https://doi.org/10.3791/58025

Interpretive Summary: Infrared analysis has revolutionized how researchers understand freezing in plants because when water freezes it gives of heat which is visible in the infrared spectrum. Observations of the world we live in are always in 3 dimensions, but it is difficult to accurately represent those observations using only 2D images. In this study plants were frozen and video-taped with 2 infrared cameras slightly different angles. Screen capture software precisely synchronized the right-left images and Adobe After Effects was used to create an anaglyph video that allowed observation of the freezing process in 3D for first time. The procedure can be used with any camera in any laboratory that uses visual data to understand biological processes.

Technical Abstract: Freezing in plants can be monitored using infrared (IR) thermography, because when water freezes, it gives off heat. However, problems with color contrast make 2-dimensions (2D) infrared images somewhat difficult to interpret. Viewing an IR image or the video of plants freezing in 3 dimensions (3D) would allow a more accurate identification of sites for ice nucleation as well as the progression of freezing. In this paper, we demonstrate a relatively simple means to produce a 3D infrared video of a strawberry plant freezing. Strawberry is an economically important crop that is subjected to unexpected spring freeze events in many areas of the world. An accurate understanding of the freezing in strawberry will provide both breeders and growers with more economical ways to prevent any damage to plants during freezing conditions. The technique involves a positioning of two IR cameras at slightly different angles to film the strawberry freezing. The two video streams will be precisely synchronized using a screen capture software that records both cameras simultaneously. The recordings will then be imported into the imaging software and processed using an anaglyph technique. Using red-blue glasses, the 3D video will make it easier to determine the precise site of ice nucleation on leaf surfaces.