Split‐root system optimization based on the survival, growth and development of the model Poaceae Brachypodium distachyon

Abstract

Split‐root system has been developed to better understand plant response to environmental factors, by exposing two separate parts of a single root system to heterogeneous situations. Surprisingly, there is no study attempting to maximize plant survival, growth and root system structure through a statistically sound comparison of different experimental protocols. Here, we aim at optimizing split‐root systems on the model plant for Poaceae and cereals Brachypodium distachyon in terms of plant survival, number of roots and their equal distribution between the two compartments. We tested the effect of hydroponic or soil as growing media, with or without change of media at the transplantation step. The partial or total cutting of roots and/or shoots was also tested in different treatments as it could have an influence on plant access to energy and water and consequently on survival, growth and root development. Growing plants in soil before and after transplantation in split‐root system was the best condition to get the highest survival rate, number of coleoptile node axile roots and growth. Cutting the whole root system was the best option to have a high root biomass and length at the end of the experiment. However, cutting shoots was detrimental for plant growth, especially in terms of root biomass production. In well‐watered conditions, a plant submitted to a transfer in a split‐root system is thus mainly lacking energy to produce new roots thanks to photosynthesis or adaptive autophagy, not water or nutrients.

Conserved, divergent and heterochronic gene expression during Brachypodium and Arabidopsis embryo development

“…Thus, it represents a “wild” grass model. The Brachypodium genome has been sequenced (The International Brachypodium Initiative 2010 ), and the species is being used as model for bioenergy (Cass et al 2016 ), root development (Agapit et al 2020 ) and flowering (Qin et al 2017 ), among others. Given that closely related crop relatives, such as wheat, are seed crops, there is an interest in understanding the control of embryo and grain development.…”

Specialized Plant Growth Chamber Designs to Study Complex Rhizosphere Interactions

“…In essence, the split-root system directs the growth of the roots to generally two different growth conditions and enables the investigation of whether a local stimuli (microbial interactions, nutrient limitations, etc.) have a local or global response which can be observed at the root or shoot level (Agapit et al, 2020). Split-root systems are widely studied (Larrainzar et al, 2014;Saiz-Fernández et al, 2021) and have been adapted to rhizoboxes (Zhu and Yao, 2004;Mitchell et al, 2018) as well as to pots and tubes (Kosslak and Bohlool, 1984;Marschner and Baumann, 2003).…”

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 ).…”