Project acronym CELLONGATE
Project Unraveling the molecular network that drives cell growth in plants
Researcher (PI) Matyas FENDRYCH
Host Institution (HI) UNIVERZITA KARLOVA
Call Details Starting Grant (StG), LS3, ERC-2018-STG
Summary Plants differ strikingly from animals by the almost total absence of cell migration in their development. Plants build their bodies using a hydrostatic skeleton that consists of pressurized cells encased by a cell wall. Consequently, plant cells cannot migrate and must sculpture their bodies by orientation of cell division and precise regulation of cell growth. Cell growth depends on the balance between internal cell pressure – turgor, and strength of the cell wall. Cell growth is under a strict developmental control, which is exemplified in the Arabidopsis thaliana root tip, where massive cell elongation occurs in a defined spatio-temporal developmental window. Despite the immobility of their cells, plant organs move to optimize light and nutrient acquisition and to orient their bodies along the gravity vector. These movements depend on differential regulation of cell elongation across the organ, and on response to the phytohormone auxin. Even though the control of cell growth is in the epicenter of plant development, protein networks steering the developmental growth onset, coordination and termination remain elusive. Similarly, although auxin is the central regulator of growth, the molecular mechanism of its effect on root growth is unknown. In this project, I will establish a unique microscopy setup for high spatio-temporal resolution live-cell imaging equipped with a microfluidic lab-on-chip platform optimized for growing roots, to enable analysis and manipulation of root growth physiology. I will use developmental gradients in the root to discover genes that steer cellular growth, by correlating transcriptome profiles of individual cell types with the cell size. In parallel, I will exploit the auxin effect on root to unravel molecular mechanisms that control cell elongation. Finally, I am going to combine the live-cell imaging methodology with the gene discovery approaches to chart a dynamic spatio-temporal physiological map of a growing Arabidopsis root.
Summary
Plants differ strikingly from animals by the almost total absence of cell migration in their development. Plants build their bodies using a hydrostatic skeleton that consists of pressurized cells encased by a cell wall. Consequently, plant cells cannot migrate and must sculpture their bodies by orientation of cell division and precise regulation of cell growth. Cell growth depends on the balance between internal cell pressure – turgor, and strength of the cell wall. Cell growth is under a strict developmental control, which is exemplified in the Arabidopsis thaliana root tip, where massive cell elongation occurs in a defined spatio-temporal developmental window. Despite the immobility of their cells, plant organs move to optimize light and nutrient acquisition and to orient their bodies along the gravity vector. These movements depend on differential regulation of cell elongation across the organ, and on response to the phytohormone auxin. Even though the control of cell growth is in the epicenter of plant development, protein networks steering the developmental growth onset, coordination and termination remain elusive. Similarly, although auxin is the central regulator of growth, the molecular mechanism of its effect on root growth is unknown. In this project, I will establish a unique microscopy setup for high spatio-temporal resolution live-cell imaging equipped with a microfluidic lab-on-chip platform optimized for growing roots, to enable analysis and manipulation of root growth physiology. I will use developmental gradients in the root to discover genes that steer cellular growth, by correlating transcriptome profiles of individual cell types with the cell size. In parallel, I will exploit the auxin effect on root to unravel molecular mechanisms that control cell elongation. Finally, I am going to combine the live-cell imaging methodology with the gene discovery approaches to chart a dynamic spatio-temporal physiological map of a growing Arabidopsis root.
Max ERC Funding
1 498 750 €
Duration
Start date: 2019-01-01, End date: 2023-12-31
Project acronym InPhoTime
Project Insect Photoperiodic Timer
Researcher (PI) David DOLEZEL
Host Institution (HI) Biologicke centrum AV CR, v. v. i.
Call Details Consolidator Grant (CoG), LS3, ERC-2016-COG
Summary Daylength measuring devices such as the photoperiodic timer enable animals to anticipate and thus survive adverse seasons. This ability has contributed to the great success of insects living in temperate regions. Yet the basis of photoperiodic sensing remains elusive, because of the lack of suitable genetic models expressing photoperiod-dependent seasonal phenotypes. We have developed the linden bug, Pyrrhocoris apterus, into a genetically tractable model with a robust, photoperiod-dependent reproductive arrest (diapause). With the available tools, this insect has become ideal for deciphering the regulation of seasonality. The project has 3 clear and ambitious objectives: 1). Our goal is to define the molecular and anatomical bases of the photoperiodic timer. To achieve this, we propose to identify photoperiodic timer genes, genes regulating input to the timer, and early output markers, through an RNA interference screen(s). To define the molecular mechanism of the timer, we will employ genome editing to precisely alter properties of the key players. 2). Next, we will combine techniques of neuronal backfilling, in-vivo fluorescent reporters, and microsurgery to define the photoperiodic timer anatomically and to examine its spatial relationship to the circadian clock in the insect brain. 3). We will exploit the great natural geographic variability of photoperiodic timing in P. apterus to explore its genetic basis. Genetic variants correlating with phenotypic differences will be causally tested by genome editing within the original genetic backgrounds. Both the established and the innovative strategies provide a complementary approach to the first molecular characterization of the seasonal photoperiodic timer in insects. The proposed research aspires to explain mechanisms underlying the critical physiological adaptation to changing seasons. Deciphering mechanisms underpinning widespread adaptation might bring general implications for environment-friendly pest control.
Summary
Daylength measuring devices such as the photoperiodic timer enable animals to anticipate and thus survive adverse seasons. This ability has contributed to the great success of insects living in temperate regions. Yet the basis of photoperiodic sensing remains elusive, because of the lack of suitable genetic models expressing photoperiod-dependent seasonal phenotypes. We have developed the linden bug, Pyrrhocoris apterus, into a genetically tractable model with a robust, photoperiod-dependent reproductive arrest (diapause). With the available tools, this insect has become ideal for deciphering the regulation of seasonality. The project has 3 clear and ambitious objectives: 1). Our goal is to define the molecular and anatomical bases of the photoperiodic timer. To achieve this, we propose to identify photoperiodic timer genes, genes regulating input to the timer, and early output markers, through an RNA interference screen(s). To define the molecular mechanism of the timer, we will employ genome editing to precisely alter properties of the key players. 2). Next, we will combine techniques of neuronal backfilling, in-vivo fluorescent reporters, and microsurgery to define the photoperiodic timer anatomically and to examine its spatial relationship to the circadian clock in the insect brain. 3). We will exploit the great natural geographic variability of photoperiodic timing in P. apterus to explore its genetic basis. Genetic variants correlating with phenotypic differences will be causally tested by genome editing within the original genetic backgrounds. Both the established and the innovative strategies provide a complementary approach to the first molecular characterization of the seasonal photoperiodic timer in insects. The proposed research aspires to explain mechanisms underlying the critical physiological adaptation to changing seasons. Deciphering mechanisms underpinning widespread adaptation might bring general implications for environment-friendly pest control.
Max ERC Funding
2 000 000 €
Duration
Start date: 2017-04-01, End date: 2022-03-31
