Evolution of Root Phenotypes in Maize Domestication Reveals Key Adaptations

Strategic Insights -

Researchers at the Gregor Mendel Institute of Molecular Plant Biology in Wien, Austria, have made a groundbreaking discovery in the field of agriculture, shedding light on the evolution of root phenotypes in maize domestication over the past 18,000 years. By analyzing ancient DNA, paleobotany, and functional-structural modeling, the team reconstructed the root phenotypes of maize and teosinte, uncovering significant adaptations that enabled maize to thrive in changing environments. The findings suggest that increasing atmospheric CO concentrations, irrigation, and human population growth influenced the evolution of root phenotypes, ultimately leading to deeper root systems and enhanced plant performance under nitrogen stress.

Key Takeaways:

  • The study examined the evolution of root phenotypes from teosinte to maize, a transition resulting in reduced nodal root number (NRN), multiseriate cortical sclerenchyma (MCS), and increased seminal root number (SRN).
  • The researchers reconstructed the root phenotypes of maize and teosinte, as well as the environments of the Tehuacan Valley over the last 18,000 years using a combination of ancient DNA, paleobotany, and functional-structural modeling.
  • The analysis revealed that increasing Holocene atmospheric CO concentrations favored the appearance of reduced NRN and MCS between 12,000 and 8,000 years before present (yrBP), promoting deeper root systems.
  • The advent of irrigation by 6,000 yrBP switched nitrogen distribution from topsoil to subsoil domains, increasing the utility of reduced NRN and MCS.
  • Comparison of allelic frequencies among ancient samples suggests that increased SRN may have appeared around 3,500 yrBP, coinciding with a period of increased human population, agricultural intensification, and soil degradation.
  • The research concluded that root phenotypes that enhance plant performance under nitrogen stress are crucial for maize adaptation to changing agricultural practices in the Tehuacan Valley.
  • The study's findings have significant implications for crop domestication and breeding, particularly in regions with limited water resources and high levels of soil degradation.

Statistics:

  • 18,000 years: The time period over which the team reconstructed the root phenotypes of maize and teosinte.
  • 12,000 - 8,000 years before present (yrBP): The period during which increasing Holocene atmospheric CO concentrations favored the appearance of reduced NRN and MCS.
  • 6,000 yrBP: The time when irrigation was introduced, switching nitrogen distribution from topsoil to subsoil domains.
  • 3,500 yrBP: The estimated time when increased SRN may have appeared, coinciding with a period of increased human population and agricultural intensification.
  • 5500 - 500 yrBP: The time range of ancient samples analyzed for allelic frequencies.
  • 3500 yrBP: The estimated time when increased SRN may have appeared, leading to deeper root systems and enhanced plant performance under nitrogen stress.

Sources:

  • In silico analysis of the evolution of root phenotypes during maize domestication in Neolithic soils of Tehuacan. New Phytologist, 2025.
  • Miguel Vallebueno-Estrada, Gregor Mendel Institute of Molecular Plant Biology GmbH: Vienna, Wien, 1030, Austria.
  • Ivan Lopez-Valdivia, Harini Rangarajan, Kelly Swarts, Bruce F. Benz, Michael Blake, Jagdeep Singh Sidhu, Sergio Perez-Limon, Ruairidh J. H. Sawers, Hannah Schneider, Jonathan P. Lynch, and others (2025). In silico analysis of the evolution of root phenotypes during maize domestication in Neolithic soils of Tehuacan. New Phytologist, 2025.
  • NewsRx. Gregor Mendel Institute of Molecular Plant Biology Reports Findings in Agriculture (In silico analysis of the evolution of root phenotypes during maize domestication in Neolithic soils of Tehuacan). Agriculture Week. June 12, 2025; p 1385.