Background and Aims Root proliferation is a response to a heterogeneous nutrient distribution. However, the growth of root hairs in response to heterogeneous nutrients and the relationship between root hairs and lateral roots remain unclear. This study aims to understand the effects of heterogeneous nutrients on root hair growth and the trade-off between root hairs and lateral roots in phosphorus (P) acquisition. Methods Near-isogenic maize lines, the B73 wild type (WT) and the rth3 root hairless mutant, were grown in rhizoboxes with uniform or localized supply of 40 (low) or 140 (high) mg P kg−1 soil. Results Both WT and rth3 had nearly two-fold greater shoot biomass and P content under local than uniform treatment at low P. Significant root proliferation was observed in both WT and rth3 in the nutrient patch, with the WT accompanied by an obvious increase (from 0.7 to 1.2 mm) in root hair length. The root response ratio of rth3 was greater than that of WT at low P, but could not completely compensate for the loss of root hairs. This suggests that plants enhanced P acquisition through complementarity between lateral roots and root hairs, and thus regulated nutrient foraging and shoot growth. The disappearance of WT and rth3 root response differences at high P indicated that the P application reduced the dependence of the plants on specific root traits to obtain nutrients. Conclusions In addition to root proliferation, the root response to a nutrient-rich patch was also accompanied by root hair elongation. The genotypes without root hairs increased their investment in lateral roots in a nutrient-rich patch to compensate for the absence of root hairs, suggesting that plants enhanced nutrient acquisition by regulating the trade-off of complementary root traits.

中文翻译：

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异质养分供应促进玉米生长和磷获取：侧根和根毛的加性和补偿作用

背景和目的 根系增殖是对异质养分分布的一种反应。然而，对异质营养物质的响应根毛的生长以及根毛与侧根之间的关系仍不清楚。本研究旨在了解异质营养素对根毛生长的影响以及根毛和侧根在磷 (P) 获取方面的权衡。方法 近等基因玉米品系，B73 野生型 (WT) 和 rth3 根无毛突变体，在均匀或局部供应 40（低）或 140（高）mg P kg-1 土壤的 rhizoboxes 中生长。结果 WT 和 rth3 在局部处理下的枝条生物量和 P 含量是低 P 下均匀处理的近两倍。在营养斑块中，WT 和 rth3 均观察到显着的根系增殖，WT 伴随着根毛长度的明显增加（从 0.7 到 1.2 毫米）。rth3在低磷下的根系响应比大于WT，但不能完全弥补根毛的损失。这表明植物通过侧根和根毛之间的互补性增强了磷的获取，从而调节了养分觅食和枝条生长。WT 和 rth3 在高磷下根系响应差异的消失表明磷的施用降低了植物对特定根系获得养分的依赖。结论 除根系增殖外，根系对营养丰富的斑块的反应还伴随着根毛伸长。没有根毛的基因型在营养丰富的斑块中增加了对侧根的投资，以弥补根毛的缺失，