Middle layers of cortex create air tunnels that enable gas exchange during flooding, while on-demand expansion of the cortex can reduce water loss during drought stress. For example, the inner cortex layer is where symbiotic fungi exchange nutrients with the plant, and increased cooperation could help lessen the carbon footprint of agriculture.

In addition, the cortex cellular subtypes are of critical importance for traits that help crop plants cope with environmental stressors. The cortex is particularly important because it comprises the bulk of the early corn root and has more than 10 layers. The new map of the corn root revealed previously undescribed cellular specialization in the cortex of the root. 'This second layer of information essentially gave us the puzzle box that allowed us to precisely map cells to their appropriate location in order to recreate a 3D model of gene expression throughout the entire corn root,' said Carlos Ortiz Ramirez of the NYU Center for Genomics and Systems Biology and UGA Laboratorio Nacional de Genómica para la Biodiversidad in Mexico, who was the first author of the study. To solve the puzzle, the researchers used fluorescent dyes that penetrated into root tissues at variable depths to label and isolate different layers, like separating the layers of an onion, giving them gene landmarks to map the single 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. New approaches then allowed them to analyze mRNA content of individual cells-distinguishing molecular features that lead to specific types of specialized cells-using miniaturized droplet-based single cell-sequencing techniques.

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. 'These traits will be critical targets to allow plants to withstand global warming and reduce the carbon footprint of crops,' added Birnbaum, whose lab at NYU led the project in collaboration with researchers at Cold Spring Harbor Laboratory and the University of Pennsylvania. 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,' said Kenneth Birnbaum, a professor in New York University's Department of Biology and Center for Genomics and Systems Biology and the senior author of the paper, which appears in the journal Science. 'We discovered how corn expands its cortex tissue, which makes up much of the crop's root system.

Honey select corn