Discovering How Root Sense Hard Soils

Lead Research Organisation: University of Nottingham
Department Name: Sch of Biosciences

Abstract

Soil compaction represents a major challenge facing modern agriculture. When combined with other stresses
like drought, soil compaction can reduce crop yields by up to 75% and causes billions of Euros in losses
annually. The GROUNDBREAKING project addresses how plant roots sense different levels of soil
compaction and modify their growth. This Project builds on my recent discovery that root responses to a
high level of soil compaction are controlled by the gaseous signal "ethylene" (Pandey et al., 2021, Science,
Huang et al., 2022, PNAS). However, agriculture soils vary greatly in terms of their hardness. Europe, in
addition to 36-million hectares of highly compacted soil, contains 25-million-hectares of soil prone to medium
compaction. Therefore, discovering which signalling pathways control root sensing of low to medium and
high to very high levels of soil compaction is vital for developing more climate resilient crops.
I hypothesise that roots employ novel volatile signals to sense medium levels of soil compaction, and
mechanical signalling pathways to sense very high level of soil compaction. The premise of this novel
signalling paradigm is based on the size of volatile signalling molecules and soil pores that impact the ability
of gaseous signals to diffuse through compacted soil. However, when soil pore size is too small to allow
gaseous exchange for even small signals like ethylene, mechanical signalling will take over to control root
responses in very highly compacted soil.

The GROUNDBREAKING project will pioneer the characterisation of novel volatile and mechanical
signalling pathways I have recently identified control root compaction responses, revealing their underlying
molecular, cellular and tissue-scale mechanisms, then creating a new paradigm for root-soil signalling. To
realise these ambitious goals, I will integrate interdisciplinary expertise in soil physics, state-of-the-art non-invasive imaging,
cutting edge molecular biology and genetic approaches under natural soil conditions.
The GROUNDBREAKING project is also very timely as the new knowledge generated about compaction
responses will underpin efforts to engineer crop roots to grow deeper and access more reliable water resources.

Publications

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