Background 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.

中文翻译：

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根毛表型影响玉米的氮获取

背景和目的 对根毛用于氮 (N) 获取的效用知之甚少。方法 我们探索了在功能结构模型 SimRoot 和具有可变根毛长度 (RHL) 的玉米基因型中，在温室和田间环境中根毛在 N 获取中的效用。主要结果 模拟结果表明，长而密的根毛可以在不同的 N 可用性下提高 N 的获取。在温室中，铵的有效性对 RHL 没有影响，低硝酸盐的有效性增加了 RHL，而在田间低氮降低了 RHL。与短 RHL 表型相比，在温室中低氮条件下，较长的 RHL 与生物量增加 216% 和植物 N 含量增加 237% 相关，并且与短 RHL 表型相比，田间生物量增加 250% 和植物 N 含量增加 200% . 在低 N 场环境中，具有长 RHL 的基因型的产量比具有短 RHL 的基因型高 267%。我们推测，长根毛通过增加根表面积和扩大根表面周围 N 耗竭区以外的土壤勘探来改善 N 捕获。结论 我们得出结论，根毛在氮的获取中起重要作用。我们建议根毛值得考虑作为改善玉米和其他作物氮获取的育种目标。