Localized micronutrient patches induce lateral root foraging and chemotropism in Nicotiana attenuata

查看全文 作　　者：Abigail P. [1]Ferrieri;Ricardo A. R. [1,2]Machado;Carla C. M. [1,2]Arce;Danny [1]Kessler;lan T. [1]Baldwin;Matthias [1,2]Erb 机构地区：[1]Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany;[2]Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland 出　　处：《Journal of Integrative Plant Biology》索引2017年第59卷第10期,共13页 基　　金：the Max Planck Society,European Research Council Advanced Grant(No.293926 to ITB);Alexander von Humboldt Postdoctoral Research Fellowship (to APF);Brazilian National Council for Research (CNPq; grant no.237929/2012-0 to CCMA) for financial support 摘　　要：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. 关 键 词：LOCALIZED MICRONUTRIENT PATCHES NICOTIANA attenuata