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

点击翻译按钮获取中文摘要

BackgroundPlants 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.Objectives1. 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.NoveltyAlthough 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. TimelinessInhibition 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 ApproachTo 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.