WATER_TRAFFIC · Cellular mechanisms controlling the water permeability of the plant plasma membrane
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2004-11-01 → 2005-10-31
- EU contribution
- €40,000
- Participants
- 1
- Scheme
- ERG
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Results in brief
Final Activity Report Summary - WATER_TRAFFIC (Cellular mechanisms controlling the water permeability of the plant plasma membrane)
During the research period, I succeed in getting a research position at the Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture Faculty of Agricultural, Food and Environmental Quality Science, the Hebrew University of Jerusalem. As for my research objectives: - First, I established in Israel the unique system designed to measure the plant cell water permeability. The advantages of this method are in its simplicity, high efficiency and accuracy. This system was mainly developed during my post doc period at the lab of Prof. Francois Chaumont. Establishing it again in Israel had a key role for fulfilling my other research objectives. - Second, I completed several preliminary experiments which were aimed to test the feasibility of performing Ca2+ and pH imaging in to the root cells. Since these experiments could carry many pitfalls and problems, for example: the loading technique of the imaging dye in to the cytoplasm. I succeed in proving that the root tissue could be loaded in with Acetoxymethyl ester (AM) dyes. I tested maize root tip response to loading of AM dye (fluorescein diacetate; FDA). This test proves that in principle the AM method could apply to our root system. - Third, I had major progress in establishing a novel, homologous, in-planta, functional expression system for both quality and quantity AQP permeability measurements. This system is expected to replace the heterologous (Xenopus oocyte) system by incorporating the advantages of a higher expression and targeting rate of plant AQPs, with higher accuracy in determining the Pf, and the ability to provide reliable comparison testing between different AQP isoforms. During my reintegration period I have: - published the following peer reviewed paper: Chaumont F., Moshelion M. and Daniels M. J. (2005) 'Regulation of plant aquaporin activity'. Biology of the Cell 97: 749-764; - delivered lecture at international scientific workshop: New tools for molecular studies of water transport in plants (2005) Aquaporins biophysical and molecular mechanisms for water transport - international course Villa Gualino, Turin, Italy; - presented my scientific work at international conferences: Menachem Moshelion, Charles Hachez, Arnaud-Bernard Martin, Mohammed Bajji, and François Chaumont (2005) Zea mays Aqp2;4 and Aqp2;6 play a central role in the maize water conductivity control. The Fourth International Conference on Aquaporins, Brussels, Belgium.
Data: CORDIS, © European Union
Project objective
The prominent role of water in the plant life provides the motivation for a number of scientific groups to investigate the role of water channels, aquaporins (AQPs), in the plant water relations. AQPs are present in all the living organisms that have been researched to date. They transport water as well as small neutral solutes across the cell membranes.The understanding of the AQP molecular functionality and structure progressed considerably during the last decade. In spite of that, the mechanism by which the AQP activity is being regulated at the plant cell level is still poorly understood. Our main objectives are to achieve a better understanding of the mechanism controlling the water permeability at the level of a single cell via the regulation of its plasma membrane AQPs, and to correlate this mechanism with the whole plant-water relationship.Two major mechanisms are likely to be involved: gating (conformational changes of the AQPs) and trafficking (shuttling of small vesicles rich in AQPs). Specific AQ P gating models in plants are based mainly on data obtained after plant AQP expression in Xenopus oocytes (e.g. gating behaviour of AtPIP2;2. controlled by the cytosolic pH, of Soybean nodulin 26 controlled by phosphorylation). Trafficking models in plants are based on proteins other than AQPs (e.g. Auxin transporter PINI) or on mammalian AQP2 and AQP4 trafficking models. Identifying similar mechanisms directly involved in the regulation of plant cell water permeability should enable us to achieve these objectives.To this end, we plan to investigate the plant AQP activity using specific chemicals known to affect the cellular concentrations of protons or Ca2+, second messenger ions involved in many regulations processes.
Original text from CORDIS.
Participants
- THE HEBREW UNIVERSITY OF JERUSALEM · JERUSALEMCoordinatorIsrael
Links
Data: CORDIS, © European Union