Patompong SaengwilaiChristopher StrockHarini RangarajanJoseph ChimunguJirawat SalungyuJonathan P. LynchThailand Ministry of EducationMahidol UniversityPennsylvania State University2022-08-042022-08-042021-11-09Annals of Botany. Vol.128, No.7 (2021), 849-85810958290030573642-s2.0-85121139352https://repository.li.mahidol.ac.th/handle/123456789/75538Background and Aims: The utility of root hairs for nitrogen (N) acquisition is poorly understood. Methods: We explored the utility of root hairs for N acquisition in the functional-structural model SimRoot and with maize genotypes with variable root hair length (RHL) in greenhouse and field environments. Key Results: Simulation results indicate that long, dense root hairs can improve N acquisition under varying N availability. In the greenhouse, ammonium availability had no effect on RHL and low nitrate availability increased RHL, while in the field low N reduced RHL. Longer RHL was associated with 216 % increase in biomass and 237 % increase in plant N content under low-N conditions in the greenhouse and a 250 % increase in biomass and 200 % increase in plant N content in the field compared with short-RHL phenotypes. In a low-N field environment, genotypes with long RHL had 267 % greater yield than those with short RHL. We speculate that long root hairs improve N capture by increased root surface area and expanded soil exploration beyond the N depletion zone surrounding the root surface. Conclusions: We conclude that root hairs play an important role in N acquisition. We suggest that root hairs merit consideration as a breeding target for improved N acquisition in maize and other crops.Mahidol UniversityAgricultural and Biological SciencesArticleSCOPUS10.1093/aob/mcab104