This detailed 3D representation of a developing soy flower was created using a new X-ray microscopy method. It enables sharp images from the cell to the whole plant.
To research and improve crops, researchers study certain traits. For example, the number of grains in maize or the seed size in wheat are important for breeding. However, these features that are visible to us are controlled by molecular processes in the plant cells that take place on a microscopic level. In the meantime, 3D imaging methods are used in biology to record such characteristics on all size scales of the plant: from the small cells to leaves and flowers.
For this, a 3D volume model is created from many individual recordings. So far, only layers with the thickness of a few cells of plant tissue and a small section of the relevant macrostructure could be displayed. However, the biologist Christopher Topp and his group at the Donald Danforth Plant Science Center in the US state of Missouri have developed a new 3D X-ray microscopy method. The scientists can use it to image plant cells in high resolution even deep in tissues and organs.
The process now opens up new possibilities for research on plants: cells of entire plant organs or in thick tissues can be sharply imaged with the aid of improved 3D X-ray microscopy. The better the resolution or the greater the magnification in X-ray microscopy, the more the sample will be damaged by the radiation used. To make the sample more robust and thus increase resolution and magnification, the researchers developed a new sample preparation process.
In addition to improved X-ray microscopy technology, a combination of X-ray microscopy for larger and scanning electron microscopy for more detailed sections contributes to good resolution in different size scales. The resulting recordings enable a more detailed analysis of the 3D representations calculated from them. The scientists optimized the acquisition parameters for a large number of plant tissues, whereas previously used methods could only be used for a limited area of ​​application.
In the future, the new imaging method will be used to examine, among other things, the natural interaction of roots and microbes underground. “Until recently, we didn’t have any tools to understand these interactions,” says Topp. “3D X-ray microscopy can help unlock the potential for restoring these natural alliances in our agricultural systems.” The research could help reduce the need to use artificial fertilizers in the future and thus contribute to environmental protection.