Split-root system as a useful tool to study woody plant biology

Abstract

The split-root system technique has been used to analyse plant biology for several decades, but woody plants have not received enough attention in this experimental approach. Historically, several methods have been developed, ranging from the simplest method of dividing a root into two parts and placing them in separate containers to more complex methods, such as grafting a second root from another plant. Each method has advantages and disadvantages that determine the goals of the experiment. Thus far, research using the split-root system has covered only 62 species of woody plants, mainly to investigate the water shortage effect on water acquisition. Many studies have also considered the significance of functional root-system diversity for plant fertilisation, which allows a better understanding of ion transport regulation mechanisms and some anatomical and functional features of woody plants. Ion uptake and transport have been studied frequently using isotope labelling. The split-root system method also offers interesting possibilities for studying the interactions of plants with other organisms. For example, this method was used to study root colonization strategies by mycorrhizal fungi. The comprehensive analysis of the split-root system technique in this review provides fine-scale information on the future concepts needed to study root-system biology, as the ability of roots to play a range of functions in the plant remains largely untested.

Neighbour-induced changes in root exudation patterns of buckwheat results in altered root architecture of redroot pigweed

“…This enables the application of differential treatments to each compartment (e.g., different plant neighbours can be present or absent in each compartment). There are different ways to set up a split-root system depending on the factors such as the aim of the study, plant age required for the treatment, and/or the type plant and its root system 35 , 36 . The availability of such diverse techniques to establish split-root systems in different plant species while treating evenly divided parts of a single root system differentially is useful for various research topics (e.g., plant nutrient uptake and transport 37 – 39 , abiotic and biotic stress 40 – 43 , hormone signalling 44 – 46 , and symbioses with soil microbes 47 ).…”