The article “Maize genetic diversity identifies moisture-dependent root-branch signaling pathways” published on BioRxiv by the Hydrosensing team.
This article investigates hydropatterning, the process by which plant root tips sense soil moisture gradients and pattern new branches toward water, focusing on its genetic basis in maize; it reveals significant differences between tropical and temperate varieties, highlights the roles of auxin and ethylene hormones in regulating root branching, and underscores the agricultural importance of this adaptive behavior.
Full reference: Scharwies, J. D., Clarke, T., Zheng, Z., Dinneny, A., Birkeland, S., Veltman, M. A., … & Dinneny, J. R. (2024). Maize genetic diversity identifies moisture-dependent root-branch signaling pathways. bioRxiv, 2024-08. https://doi.org/10.1101/2024.08.26.609741
Image: Hydropatterning responses revealed in public sector breeding lines of Zea mays (maize). (A and B) Schematic of the (A) hydropatterning response in (B) our custom-built hydropatterning assay. Primary roots of maize seedlings are grown in a vertical position along moist paper while being prevented from growing off the paper by a mesh cover. Lateral root (LR) primordia are preferentially induced towards the water-saturated paper (contact-side) and suppressed on the air-exposed side (air-side). Longitudinal cross-section of maize root (B73 inbred) stained with Calcofluor White (cell walls; gray) and SYBR Green (LRs; green). (C and D) Distribution of (C) contact-(blue) and air-side (white) LR densities from 250 maize inbred lines characterized using the hydropatterning assay and calculated (D) percent air-side LRs (purple). Each inbred line is represented by its median value (n = 1-3 seedlings/inbred) (data S2). Gray lines connect corresponding inbred lines. Population median (white circles). (E) X-ray Computed Tomography showing LR patterning on primary roots of strong (CI64) and weak (OH7B) hydropatterning inbred lines grown through an air-filled macropore in soil.
