Dissecting the role of root exudates in root density growth responses in plants

Lead Research Organisation: University of Leeds
Department Name: Sch of Biology

Abstract

Background
Plants can detect the density of roots in the rhizosphere and use this information to determine the spatio-temporal allocation of root and shoot growth. The mechanisms by which plants detect and respond to root density remain unclear, but biochemical root exudates are likely to play an important role. Strigolactones are hormones that inhibit root and shoot system growth, but which are also exuded into the soil; they are therefore an excellent candidate signalling molecule for root density perception.

Objectives
1. Assess the role of strigolactones in root density perception and response.
2. Identify novel exudates that act in plant communication in the rhizosphere.
3. Understand the mechanisms by which plants respond to high root density.

Novelty
Although plant communication in the rhizosphere is a long-recognized phenomenon, very little work has been undertaken to uncover the molecular signalling mechanisms that underlie it. This project thus represents a novel line of investigation into an important biological phenomenon.

Timeliness
Inhibition of shoot growth by high root density in agricultural contexts likely acts as a major limit on crop yield. This project is thus highly timely, as understanding this phenomenon could unlock rapid increases in yield.

Experimental Approach
To assess the role of strigolactone in root density perception, we will use existing molecular genetic tools in the model plant Arabidopsis and in the crop species pea and barley, including strigolactone mutants and reporter lines. To identify new exudates that regulate plant-plant communication, we will collect exudates from barley and fractionate them, and use mass spectrometry to identify possible candidate signalling molecules. To understand the mechanisms by which plants to respond these signals, we will screen a barley diversity panel to perform QTL mapping for genes that regulate the response to root density. We will then identify and characterise the function of these genes.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M011151/1 30/09/2015 29/09/2023
2272100 Studentship BB/M011151/1 30/09/2019 29/09/2023 Cara Wheeldon