Periodic Reporting for period 1 - HYDROSENSING (DISCOVERING HOW PLANTS SENSE WATER STRESS)
Période du rapport: 2024-05-01 au 2025-10-31
Plants and agriculture worldwide are increasingly exposed to periods of insufficient or irregular water, a problem intensified by climate change. Yet, despite its importance, scientists still do not know exactly how plants sense when water becomes scarce and convert that information into growth and survival responses, such as changes in root architecture or the closing of leaf pores. HYDROSENSING tackles this fundamental question by focusing on how plants detect changes in water availability at the cellular level and how this information is translated into the movement of the stress hormone abscisic acid (ABA) from inner vascular tissues to outer target cells in roots and leaves.
The overall objective of HYDROSENSING is to build a mechanistic “blueprint” of plant water sensing, from biophysical changes in cell walls and membranes through hormone synthesis, transport, and perception, up to whole-organ responses such as root branching and stomatal regulation. To achieve this, the consortium combines complementary expertise in genetics, structural biology, biophysics and advanced imaging. The project develops new tools, including next-generation CRISPR libraries that can simultaneously inactivate multiple related genes, cell-type specific genome editing and activation systems, and real-time imaging of water flow and cell wall dynamics at cellular resolution. These approaches are applied first in the model plant Arabidopsis and then extended to crops such as tomato and rice to test how conserved the water-sensing mechanisms are.
The expected impact of HYDROSENSING is twofold. Scientifically, the project will provide the first integrated, experimentally validated model of how plants sense and respond to water stress, revealing key molecular components and design principles that underlie root and shoot adaptation. Societally and economically, this knowledge will deliver new, well-defined targets and tools for breeding and engineering crops that use water more efficiently and maintain yield under fluctuating water conditions. At the same time, the innovative genetic and imaging platforms developed here will form a long-lasting resource for the wider life-science community, enabling researchers and breeders to interrogate complex traits that depend on water transport and signalling in many plant species.
The overall objective of HYDROSENSING is to build a mechanistic “blueprint” of plant water sensing, from biophysical changes in cell walls and membranes through hormone synthesis, transport, and perception, up to whole-organ responses such as root branching and stomatal regulation. To achieve this, the consortium combines complementary expertise in genetics, structural biology, biophysics and advanced imaging. The project develops new tools, including next-generation CRISPR libraries that can simultaneously inactivate multiple related genes, cell-type specific genome editing and activation systems, and real-time imaging of water flow and cell wall dynamics at cellular resolution. These approaches are applied first in the model plant Arabidopsis and then extended to crops such as tomato and rice to test how conserved the water-sensing mechanisms are.
The expected impact of HYDROSENSING is twofold. Scientifically, the project will provide the first integrated, experimentally validated model of how plants sense and respond to water stress, revealing key molecular components and design principles that underlie root and shoot adaptation. Societally and economically, this knowledge will deliver new, well-defined targets and tools for breeding and engineering crops that use water more efficiently and maintain yield under fluctuating water conditions. At the same time, the innovative genetic and imaging platforms developed here will form a long-lasting resource for the wider life-science community, enabling researchers and breeders to interrogate complex traits that depend on water transport and signalling in many plant species.
During the first 18 months, the consortium has established the experimental, computational and organizational foundations of HYDROSENSING and begun to generate new data on how plants sense water availability. We have set up and optimized state-of-the-art imaging pipelines, including stimulated Raman scattering microscopy to visualize water movements in living roots and leaves, and high-resolution reporters for the stress response and cell wall integrity in plants. These platforms now allow us to monitor, in real time, how hydraulic changes and ABA production or release are coupled at the level of specific cell types. In parallel, physiologically relevant perturbation systems have been implemented to impose controlled changes in water potential and cell wall viscosity, providing the experimental conditions required for Work Package 1.
Within Work Package 2, we have designed and built next-generation genetic tools to identify the “hydro-genes” that control water sensing and ABA export. This includes a transportome-scale, multi-target CRISPR library for Arabidopsis, cell-type specific CRISPR and CRISPR-activation vectors, and barcoded mutant collections that allow efficient mapping of genotype–phenotype relationships. These resources are already being used in genetic screens for altered root branching and ABA responses under fluctuating water supply, and the first candidate gene families have been identified for detailed follow-up. Several of the underlying methods and concepts have been published in leading journals such as Nature, Science Advances, Nature Photonics, and The Plant Journal, where HYDROSENSING support is acknowledged.
Work Package 3 has begun integrating emerging data into quantitative models and extending key tools to crops. We are working towards translating the genetic and imaging platforms developed in Arabidopsis into tomato and rice. A first demonstration of the work in tomato has been published in Nature Communications. Taken together, the work performed so far has delivered the main technical capabilities promised in the proposal and has begun to reveal new components and principles of plant water sensing, positioning the project well for the mechanistic and translational objectives of the remaining period.
Within Work Package 2, we have designed and built next-generation genetic tools to identify the “hydro-genes” that control water sensing and ABA export. This includes a transportome-scale, multi-target CRISPR library for Arabidopsis, cell-type specific CRISPR and CRISPR-activation vectors, and barcoded mutant collections that allow efficient mapping of genotype–phenotype relationships. These resources are already being used in genetic screens for altered root branching and ABA responses under fluctuating water supply, and the first candidate gene families have been identified for detailed follow-up. Several of the underlying methods and concepts have been published in leading journals such as Nature, Science Advances, Nature Photonics, and The Plant Journal, where HYDROSENSING support is acknowledged.
Work Package 3 has begun integrating emerging data into quantitative models and extending key tools to crops. We are working towards translating the genetic and imaging platforms developed in Arabidopsis into tomato and rice. A first demonstration of the work in tomato has been published in Nature Communications. Taken together, the work performed so far has delivered the main technical capabilities promised in the proposal and has begun to reveal new components and principles of plant water sensing, positioning the project well for the mechanistic and translational objectives of the remaining period.
HYDROSENSING has already generated several results that go beyond the current state of the art in plant biology and technology. On the technological side, the project has delivered a suite of tools that did not previously exist in plants: transportome-scale, multiplex CRISPR libraries that simultaneously inactivate several related genes; cell–type–specific genome-editing and CRISPR-activation systems; and double-barcoded mutant collections that enable efficient reverse and forward genetics. In parallel, we have implemented live imaging pipelines that, for the first time, combine quantitative measurements of water fluxes with high-resolution reporters for plant stress and shifts in cell wall integrity. Together, these platforms provide an unprecedented ability to link biophysical changes in water status with physiological dynamics and gene function.
Scientifically, the first screens and imaging experiments are revealing previously unknown components and principles of water sensing and ABA movement in roots, including candidate transporters and regulators that operate at specific boundaries between tissues. These findings open new research directions on how hydraulic signals and hormones are integrated to control root branching. In the longer term, an additional impact will come from translating these mechanistic insights into strategies to improve water-use efficiency and crop yield stability. To support further uptake, key needs include continued investment in adapting the genetic and imaging tools to major crop species and strengthening collaborations with breeding programs.
Scientifically, the first screens and imaging experiments are revealing previously unknown components and principles of water sensing and ABA movement in roots, including candidate transporters and regulators that operate at specific boundaries between tissues. These findings open new research directions on how hydraulic signals and hormones are integrated to control root branching. In the longer term, an additional impact will come from translating these mechanistic insights into strategies to improve water-use efficiency and crop yield stability. To support further uptake, key needs include continued investment in adapting the genetic and imaging tools to major crop species and strengthening collaborations with breeding programs.