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Localized micronutrient patches induce lateral root foraging and chemotropism in Nicotiana attenuata
Author(s) -
Ferrieri Abigail P.,
Machado Ricardo A. R.,
Arce Carla C. M.,
Kessler Danny,
Baldwin Ian T.,
Erb Matthias
Publication year - 2017
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12566
Subject(s) - micronutrient , biology , nutrient , lateral root , jasmonic acid , foraging , botany , ecology , chemistry , biochemistry , organic chemistry , arabidopsis , gene , mutant
Nutrients are distributed unevenly in the soil. Phenotypic plasticity in root growth and proliferation may enable plants to cope with this variation and effectively forage for essential nutrients. However, how micronutrients shape root architecture of plants in their natural environments is poorly understood. We used a combination of field and laboratory‐based assays to determine the capacity of Nicotiana attenuata to direct root growth towards localized nutrient patches in its native environment. Plants growing in nature displayed a particular root phenotype consisting of a single primary root and a few long, shallow lateral roots. Analysis of bulk soil surrounding the lateral roots revealed a strong positive correlation between lateral root placement and micronutrient gradients, including copper, iron and zinc. In laboratory assays, the application of localized micronutrient salts close to lateral root tips led to roots bending in the direction of copper and iron. This form of chemotropism was absent in ethylene and jasmonic acid deficient lines, suggesting that it is controlled in part by these two hormones. This work demonstrates that directed root growth underlies foraging behavior, and suggests that chemotropism and micronutrient‐guided root placement are important factors that shape root architecture in nature.