The role of microbial activity on crop’s tolerance to drought stress

To cope with drought, plants employ a range of strategies to reduce water loss and enhance water uptake. They may close their stomata, produce waxes, or roll their leaves to reduce transpiration rates. Solute concentration within cells may increase to sustain water extraction at lower soil water potentials, exodermis bands and lamellae help limit water loss from the root. Deep rooting growth and adjustments to the photosynthetic pathway are other strategies for coping with reduced water availability.

Just as plants have mechanisms to prevent water loss from their tissues, they must also possess strategies to retain water within the soil environment. Hydrologists have long recognized that vegetation facilitates the movement of water in soil, but understanding the specifics of how water moves around plant roots has been particularly challenging. Microorganisms are known to significantly enhance a plant's resistance to water stress ¹, yet the underlying mechanisms remain elusive.

In the laboratory, we have developed numerous technologies for studying biological processes within the soil structure. These include an environmental microscopy platform dedicated to studying microscale movements in the pore space surrounding plant roots ^2,3, various custom-made transparent soils and microcosm systems ⁴, techniques for optical manipulation of single bacterial cells in situ ⁵, label-free imaging of biological samples using the dynamics of laser speckles ⁶, and advanced microfluidic techniques ⁷. These innovations enable detailed investigation of the interactions between plants, soil, and microorganisms.

The project aims to combine these innovations to unlock the mysteries of microbial’s role as a facilitator of water movement in soil. Laboratory experiments will characterize the effects of bacterial secretions and various motility traits on the biophysics of water transport in soil. Hypotheses on water movement in the rhizosphere will be tested in microfluidic and mesocosm systems using custom-made live imaging platforms. Additionally, the project will involve collaboration with mathematicians to develop models that explore how these mechanisms can reduce water losses in the rhizosphere during drought.

Many experimental backgrounds interest us!

Observing biophysical processes in the pore spaces of granular media presents significant challenges and often necessitates a multidisciplinary approach. Our laboratory tackles these challenges with a diverse team comprising microbiologists, plant biologists, biophysicists, and mathematicians. Consequently, we welcome individuals with backgrounds in microbiology, plant biology, engineering, physics, or environmental sciences. Our primary focus is on motivation and excellence within an individual's field of expertise.

Additional details

Funder: Spanish Ministry of Science, Innovation and Universities

Location: NEIKER, Basque Institute for Agricultural Research and Development (Derio, Spain).

Supervisor: Prof Lionel DUPUY.

Duration: 4 years.

Stipend: circa €21,000 p/a after tax. 

Deadline: August / September 2024

About the supervisor

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