Seedling root system adaptation to water availability during maize domestication and global expansion

20 páginas.- 6 figuras.- 44 y 83 referencias.- The online version contains supplementary material available at https://doi.org/10.1038/s41588-024-01761-3

The maize root system has been reshaped by indirect selection during global adaptation to new agricultural environments. In this study, we characterized the root systems of more than 9,000 global maize accessions and its wild relatives, defining the geographical signature and genomic basis of variation in seminal root number. We demonstrate that seminal root number has increased during maize domestication followed by a decrease in response to limited water availability in locally adapted varieties. By combining environmental and phenotypic association analyses with linkage mapping, we identified genes linking environmental variation and seminal root number. Functional characterization of the transcription factor ZmHb77 and in silico root modeling provides evidence that reshaping root system architecture by reducing the number of seminal roots and promoting lateral root density is beneficial for the resilience of maize seedlings to drought.

This work was supported by the Deutsche Forschungsgemeinschaft (DFG) grants HO2249/22-1 to F.H. and YU272/1-1 to P.Y., the DFG Emmy Noether Programme (444755415 to P.Y.), the DFG SPP2089 “Rhizosphere spatiotemporal organisation—a key to rhizosphere functions” (403671039 to F.H. and P.Y., 403641034 to A.S.), the USDA National Institute of Food and Agriculture and Hatch Appropriations (PEN04734 and 1021929 to R.J.H.S.), Consejo Nacional de Ciencia Tecnologia (FOINS-2016-01 to R.J.H.S.), National Science Foundation (1546719 to R.J.H.S.), the National Key Research and Development Program of China (2021YFD1200700, 2016 YFD0100103 and 2020YFE0202300 to T.W.), the Innovation Program of Chinese Academy of Agricultural Sciences to T.W., the Innovation Research 2035 Pilot Plan of Southwest University (SWU-XDZD22001 to X.C.), the US Department of Agriculture, Agricultural Research Service (USDA-ARS) to V.B., the TED2021-130908B-C41/AEI/10.13039/501100011033/Unión Europea NextGenerationEU/PRTR and the Spanish Ministry of Science and Innovation for the I + D + i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033 to M.D. This work was partially funded by the DFG under Germany’s Excellence Strategy–EXC 2070 (390732324 to P.Y. and A.S.). R.K., D.v.D., R.M. and D.P. acknowledge support from the Helmholtz Association for the Forschungszentrum Jülich GmbH and thank A. Chlubek, G. Huber and J. Bühler for technical support with MRI and PET. The germplasm propagation is funded by the TRA Sustainable Futures (University of Bonn) as part of the Excellence Strategy of the federal and state governments.

Peer reviewed