X-ray analysis reveals the inner life of leaves while advancing engineering efforts to reduce 'crop sweat'

X-ray analysis of sorghum leaves has unveiled intricate details of a plant's internal system that could lead to drought-resistant crops. Researchers at the University of Illinois Urbana-Champaign, in collaboration with Argonne National Laboratory, used advanced micro-computed tomography imaging to study how air pathways, photosynthetic centers, and veins within the leaf connect to the tiny pores called stomata.

These stomata play a crucial role in plant respiration, allowing carbon dioxide to enter for photosynthesis while water escapes as a byproduct. This natural process, however, can be detrimental during hot and humid conditions, causing plants to lose significant amounts of water, much like "sweating." The study, published in Plant Physiology, led by postdoctoral researcher James Fischer, aimed to understand the relationship between stomata and the leaf's internal structure to develop crops that could maintain photosynthesis while minimizing water loss.

The researchers discovered that leaves with fewer stomata had larger air spaces beneath them, allowing for efficient CO2 distribution without excessive water loss. This finding suggests that engineering crops with fewer stomata could enhance drought resistance without compromising photosynthesis. Additionally, the study revealed that stomata on the upper surface of the leaf were positioned over veins, providing a more efficient route for CO2 to reach photosynthetic cells while facilitating cooling through reduced water loss.

These insights could pave the way for the development of crops that are better equipped to withstand drought stress, ultimately contributing to more sustainable agricultural practices.