Investigating the roles of plasma membrane aquaporins in maize water relations and leaf growth using a transgenic approach
(2017)
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- Authors
- Supervisors
- Chaumont, François
- Abstract
- Plant aquaporins are highly regulated water channels controlling the water flow across cell membranes. The quantification of the expression of plasma membrane aquaporins (PIPs) in maize roots, leaves, stomatal complexes and reproductive organs showed that the expression was dependent on the organ developmental stage and environmental conditions. This work aimed at investigating the physiological roles of PIP aquaporins using a transgenic approach. We focused our attention on PIP isoforms known to be highly or specifically expressed in some tissues. ZmPIP2;5 is one of most highly expressed aquaporins in roots and its association with apoplastic barriers suggests a role in the radial water movement. ZmPIP1;6 is almost exclusively expressed in stomatal complexes following a strict diurnal pattern and could have a role in stomatal movements in response to environmental stimuli. After transformation and selection of the maize transgenic lines overexpressing these isoforms, physiological parameters were investigated in hydroponic culture and compared to wild-type plants. Interestingly, while no differences of gas exchange were found in normal conditions or upon osmotic stress, both ZmPIP1;6 and ZmPIP2;5 overexpressing lines showed improved root hydraulic properties. The growth of these plants in water deficit conditions was analyzed in phenotyping platforms and revealed different responses to evaporative demand. ZmPIP2;5 overexpressing lines showed a better leaf growth rate under severe water stress. These data demonstrate the role of PIP aquaporins in fine-tuning the hydraulic properties of the plant to control its development and physiology in changing environmental conditions.
- Affiliations
Citations
Milhiet, T. (2017). Investigating the roles of plasma membrane aquaporins in maize water relations and leaf growth using a transgenic approach. https://hdl.handle.net/2078.5/178589