Heterogeneous Nutrient Supply Promotes Maize Growth and Phosphorus Acquisition: Additive and Compensatory Effects of Lateral Roots and Root Hairs

The study investigated the effects of heterogeneous nutrient supply on maize growth, focusing on the roles of lateral roots and root hairs in phosphorus acquisition. Using near-isogenic maize lines, including a wild type (WT) and a root hairless mutant (rth3), researchers found that both lines showed increased shoot biomass and phosphorus content when nutrients were localized rather than uniformly distributed, especially at low phosphorus levels. The WT exhibited significant root hair elongation, while the rth3 line compensated for the lack of root hairs by increasing lateral root growth. This indicated that maize plants enhanced phosphorus acquisition through a complementary relationship between lateral roots and root hairs. At high phosphorus levels, the differences in root responses between the genotypes disappeared, suggesting reduced reliance on specific root traits for nutrient uptake.