From wild to crop: unravelling the impact of root domestication on drought tolerance

Introduction

Crop domestication revolutionised human life. This process induced changes in plant traits that produced plants that grew faster and generated higher yields. However, remarkably little is known about how plant roots have changed throughout the domestication process.

Climate Change and Drought

Climate change is causing increasing droughts in many parts of the world. Given that roots are the way that water enters the plant, they are key for understanding drought tolerance. Root traits from crop ancestors could offer a route to increasing drought tolerance of modern crops.

Focus of the Study

To do this, we need to focus our efforts on the impact of domestication on roots and the rhizosphere (the zone around the root including microbes), rather than only aboveground traits as traditionally done.

Hypothesis

WILD-ROOTS will therefore test the overall hypothesis that crop domestication led to changes in root and rhizosphere traits which decreased the drought tolerance of crops compared to their wild relatives.

Methodology

WILD-ROOTS will make a holistic study of the roots and rhizospheres of a wide range of crops from diverse origins. There will be a focus on:

• Root exudation
• Volatile organic compound (VOC) emission

These are vital root processes that are crucial for many types of interactions with plants, animals, microbes, and the soil itself. Changes in root exudates and VOCs have been observed during drought conditions, but their roles in the drought tolerance of plants remain unclear.

Objectives

WILD-ROOTS will:

1. Evaluate domestication effects on the roots and rhizosphere.
2. Elucidate the mechanisms relating belowground traits to drought tolerance.
3. Use this knowledge to modernise crop models and identify belowground traits to be exploited for drought-proofing current crops.

Expected Outcomes

The results will reshape our fundamental knowledge of both the crop domestication process and how root exudation influences drought tolerance, as well as offering new approaches to boost the food security of current and future agricultural systems.