Research
Exploring Plant Hormones Dynamics
Plant hormones serve as messengers that deliver information from the environment to the plant genome, directing key processes in plants development and adaptive growth, including in crop species. In order to correctly convey such information, plant hormones must be present in the correct quantity, in the correct location and at the correct time. To insure that, plants tightly regulate their hormones response pathways at multiple levels including biosynthesis, metabolism and perception. Interestingly, and in contrast to most other organisms, plants exhibit the unique ability to spatially regulate their hormones distribution. Consequently, understanding how plants exert spatial regulation over their hormones is at the forefront of the plant sciences field. Elucidation of hormones transport mechanisms is crucial to obtaining a comprehensive understanding of their action, and opens new research avenues into the core processes they regulate and to manipulation of the agricultural traits they govern. This project explores synthetic, genetic and biochemical platforms to visualize, characterize and manipulate plant hormones dynamics in planta, combining techniques from multiple disciplines. It aims to unveil the distribution patterns of plant hormones, characterize their flow pathways and identify the molecular mechanisms that control them.
4 days old pRGA:GFP-RGA transgenic Arabidopsis seedlings were grown overnight on paclobutrazol (2 μM) then incubated with 4 (5 μM, 25 min) and PI. The seedlings were mounted on slides, irradiated with 365 nm light (2 mW/cm2, 10 seconds) at the root tip and imaged every 1 minute for 90 minutes. Red: PI. Green: GFP-RGA. Movie is at 10 fps.
Developing Opteo-Chemical Techniques
The molecular mechanisms that govern biological functions are highly sophisticated and complex. Investigation and manipulation of such processes at the molecular level require precise external spatiotemporal control over their function. Light is being harnessed to achieve this goal through a method termed “caging”, in which the biological activity of a target small- or macro-molecule is abrogated by covalent ligation to a photolabile protecting group (caging group). Exposure to light at a specific wavelength releases the molecule in its active form, facilitating direct control over its biological function. This useful method is applied to investigate and manipulate a wide range of biological processes by controlling the activity of small molecules, proteins, RNA, and DNA. Most caging groups developed to date rely on UV light for their excitation, which is problematic due to low tissue penetration and high tissue damage caused by high-energy UV irradiation. This project explores synthetic structures and pathways for developing unique caging groups, excitable by biologically benign, visible light. It aims to leverage their distinctive properties in a wide range of applications, including in plant sciences, drug delivery, and neuroscience. At the same time, it addresses basic questions in physical organic chemistry, synthetic chemistry, and spectroscopy.