A group of scientists have found the real mechanism on how plants add new cell layers that help them resist climate stressors like drought or flooding. The research funded by the US National Science Foundation focused on corn — a critically important crop around the world — to create a cell-by-cell map of the plant’s root system, which mediates drought stress and absorbs nutrients and fertilizer from the soil.
Senior author of the study Kenneth Birnbaum (New York University) said that they detected how corn expands its cortex tissue, which makes up much of the crop’s root system. The analysis was published in the journal Science. “Adding layers to the cortex tissue is a key evolutionary feature that generates ways for plants to tolerate drought and flooding and improve nutrient uptake,” the author noted.
The traits are “critical targets to allow plants to withstand global warming and reduce the carbon footprint of crops,” said Birnbaum. The research was held in collaboration with Cold Spring Harbor Laboratory and the University of Pennsylvania To create a single-cell map of the corn root, the researchers first broke apart the root using cell-wall digesting enzymes to generate single, free-floating cells.
New approaches then allowed them to analyze the mRNA content of individual cells, distinguishing molecular features that lead to specific types of specialized cells. They next mapped the cells back to their location in the corn root, akin to assembling a 10,000-piece jigsaw puzzle without a guide. To solve the puzzle, the researchers used fluorescent dyes that penetrated root tissues at variable depths to label and isolate different layers, like separating the layers of an onion, giving them gene landmarks. “The ability to leverage advances in genomics technologies allowed this research team to distinguish and spatially map individual cell types in the corn root, leading to significant new clues about how plants can adapt and survive in the face of fluctuations in environmental conditions due to climate change,” said Diane Okamuro, a program director in NSF’s Division of Integrative Organismal Biology.