Analysis of membrane traffic in adaptive stress tolerance in plants
Lead Research Organisation:
University of Glasgow
Department Name: School of Life Sciences
Abstract
Stress-mediated adaptation is a key factor in the ability of plants to cope under long-term or repeated environmental challenge, and is especially important for stomata to compensate for gas exchange during extended periods of water deficit. Stomata in the epidermis of plant leaves play a vital role in regulating CO2 exchange for photosynthesis while minimising transpirational water loss between the inner leaf air space and the atmosphere. Guard cells surrounding the stomata take up inorganic ions and water, increasing in volume to open the stomatal pore when CO2 in the leaf is depleted; and they lose ions, other solutes and water, decreasing in volume to close the stomatal pore and conserve leaf water under stress, in the dark and when CO2 is high. Arguably, stomata are at the centre of a crisis in water availability that is expected to unfold over the next 20-30 years. Globally, water usage has increased 6-fold in the past 100 years, twice as fast as the human population, and is expected to double again before 2040, driven mainly by irrigation and agriculture. Clearly, a full understanding of guard cells and stomatal regulation will have significant implications for future efforts to improve the water use efficiency of agricultural crops and, consequently, for society to face these future challenges. In fact, we know a great deal about the cellular and molecular physiology of guard cells, especially in relation to abscisic acid (ABA), salinity and drought that triggrer stomata to close, and the depth and breadth of this information has helped to elevate the guard cell system to that of one of the best understood plant cell models. However, virtually all of this knowledge centres on the short-term responsive behaviour of guard cells. By contrast, our knowledge is remarkably poor of the mechanisms by which guard cells adjust stomatal movements to adapt to longer-term environmental stress. Recently, this laboratory observed that ABA triggers the traffic to an internal compartment of one of the plasma membrane K+ channels mediating ion fluxes in guard cells. This response shows all the hallmarks essential for a function in adaptive modulation of the channel population. It complements a second discovery that the Arabidopsis mutant Atsyp121, which is defective in a major vesicle trafficking protein at the plasma membrane, selectively impairs the ability of stomata to 'remember' the recent history of stress and remain closed (so-called 'progammed' stomatal closure). These discoveries firmly tie membrane vesicle trafficking to [Ca2+]i signalling and adaption in guard cells, and suggest that K+ channel traffic between the plasma membrane and the internal compartment is an important mechanism for adaptation in these cells. I propose to address this idea directly using cellular and molecular tools now available in the laboratory. The outcome will greatly extend our understanding of ABA signalling and adaptation in plants, and should add fundamentally to our knowledge of the dynamics of membrane traffic and ion channel control in eukaryotic cells generally.
Technical Summary
Guard cells are able to adapt stomatal response to the past history of stress, as evinced by a number of well-defined behaviours such as so-called 'programmed' stomatal closure which reflects an ability to 'remember' the recent history of stress. Yet our knowledge is remarkably poor of the mechanisms that underlie this, and similar processes in plants and other eukaryotes. We recently discovered (i) that the water-stress hormone ABA triggers the traffic to an endosomal compartment of one of the plasma membrane K+ channels mediating ion fluxes in guard cells, and (ii) that the Arabidopsis mutant Atsyp121, which is defective in a major trafficking protein at the plasma membrane, impairs progammed stomatal closure. These discoveries firmly tie membrane traffic to [Ca2+]i signalling and adaption in guard cells. They lead to the postulate that K+ channel traffic is important to adapt the capacity for solute flux across the guard cell membrane to the recent history of stress. I propose to follow this line of enquiry to address three key questions underlying this postulate: (i) Is ABA-evoked channel traffic integrated with known ABA signalling pathways? (ii) Do the K+ channels recycle to the plasma membrane and is internalisation and/or recycling affected by the Atsyp121 mutant? Finally, (iii) Does the programmed closure stimulus and/or ABA evoke a traffic of other ion channel proteins associated with ABA signalling? The work will make use of a combination of confocal imaging and electrophysiological techniques, taking advantage of a toolchest of marker constructs and mutants now on hand in the laboratory, and will be supported by biochemical and cell fractionation studies. Various strategies will be used, including a combination of 'pulse-chase', localisation and kinetic analyses as well as in vivo epitope labelling methods.
People |
ORCID iD |
Michael Blatt (Principal Investigator) |
Publications
Bassham DC
(2008)
SNAREs: cogs and coordinators in signaling and development.
in Plant physiology
Besserer A
(2012)
Selective regulation of maize plasma membrane aquaporin trafficking and activity by the SNARE SYP121.
in The Plant cell
Blatt MR
(2014)
Applications of fluorescent marker proteins in plant cell biology.
in Methods in molecular biology (Clifton, N.J.)
Blatt MR
(2022)
What can mechanistic models tell us about guard cells, photosynthesis, and water use efficiency?
in Trends in plant science
Blatt MR
(2018)
New Faces behind the Scenes.
in Plant physiology
Blatt MR
(2014)
Exploring emergent properties in cellular homeostasis using OnGuard to model K+ and other ion transport in guard cells.
in Journal of plant physiology
Blatt MR
(2017)
Small Pores with a Big Impact.
in Plant physiology
Blatt MR
(2018)
Plant Physiology Launches Associate Features Editors.
in Plant physiology
Blatt MR
(2013)
The conceptual approach to quantitative modeling of guard cells.
in Plant signaling & behavior
Caesar K
(2011)
A fast brassinolide-regulated response pathway in the plasma membrane of Arabidopsis thaliana.
in The Plant journal : for cell and molecular biology
Description | Work on this project established a direct connection between membrane traffic and the ability of guard cells (and hence gas exchange for photosynthesis) to adapt to repeated stresses. In effect, the findings demonstrate a key role for membrane traffic in the 'memory' of the plant as it relates to the history of stress experience. |
Exploitation Route | This is purely fundamental research, but could help inform future efforts at improving crop performance in the field. |
Sectors | Agriculture Food and Drink Education Other |
Title | 2in1 vector systems |
Description | Synthetic biology vectors for transient and stable transformation with quantitative visual reporting on cell-by-cell basis |
Type Of Material | Technology assay or reagent |
Year Produced | 2009 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and over 100 research groups worldwide Vector system distributions to more than 500 research groups worldwide |
URL | http://psrg.org.uk |
Title | EZ-Rhizo |
Description | Computer software tool for quantitative measurement and analysis of root growth/development |
Type Of Material | Physiological assessment or outcome measure |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | Henry |
Description | Software for electrophysiology and imaging data aquisition and analysis |
Type Of Material | Technology assay or reagent |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | Multicistronic vector systems |
Description | Synthetic biology vector systems for transient and stable transformation for expressing multiple, tagged proteins and for quantitative analysis of membrane traffic and transport |
Type Of Material | Technology assay or reagent |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and over 100 research groups worldwide Vector system distributions to more than 500 research groups worldwide |
URL | http://psrg.org.uk |
Title | OnGuard |
Description | Systems biology software for quantitative modelling of cellular transport and homeostasis |
Type Of Material | Physiological assessment or outcome measure |
Year Produced | 2012 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | SUS vector systems |
Description | Synthetic biological vector systems for protein-protein interaction screening |
Type Of Material | Technology assay or reagent |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and over 100 research groups worldwide Vector system distributions to more than 500 research groups worldwide |
URL | http://psrg.org.uk |
Title | Software tools for electrophysiology and imaging |
Description | The laboratory continues to develop and refine software/hardware tools for data acquisition and analysis relevant to electrophysiology, single-cell imaging and analysis. These activities are long-standing and open-ended, and develop in line with the current research activities and needs of the laboratory. All software and related packages are made freely available to the research community through the laboratory website at psrg.org.uk |
Type Of Material | Technology assay or reagent |
Provided To Others? | Yes |
Impact | The various software tools and packages have furthered the research activities of the laboratory since the 1990s and continue to provide key support and drivers for advancing much of current research. These tools and packages are disseminated, on average, to over 100 laboratories per year. |
URL | http://psrg.org.uk |
Title | EZ-Rhizo |
Description | Software for quantitative trait analysis and acquisition for root growth/development |
Type Of Material | Database/Collection of data |
Year Produced | 2010 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | Henry |
Description | Software package for electrophysiology and imaging data acquisition and analysis |
Type Of Material | Data handling & control |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | OnGuard |
Description | Quantitative systems biology modelling of cellular transport and homeostasis |
Type Of Material | Computer model/algorithm |
Year Produced | 2012 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Title | SDM-assist |
Description | Software for molecular primer design that enables introduction of silent markers for molecular cloning |
Type Of Material | Data analysis technique |
Year Produced | 2013 |
Provided To Others? | Yes |
Impact | Multiple publications from my own research group and research groups worldwide Online distribution has been accessed through the laboratory website with site views at a rate of >500 per month |
URL | http://psrg.org.uk |
Description | PBL |
Organisation | Plant Bioscience Limited Technology |
Country | United Kingdom |
Sector | Private |
PI Contribution | IPR on ABA receptor technology and ABA signalling |
Collaborator Contribution | Funding related to IPR on ABA receptor technology and ABA signalling |
Impact | Multiple outcomes in publications and industrial contacts |
Description | PSG |
Organisation | POSCO - South Korea |
Country | Korea, Republic of |
Sector | Private |
PI Contribution | Base support for meetings and exchange of materials |
Collaborator Contribution | Base support for meetings and exchange of materials |
Impact | Base support for meetings and exchange of materials |
Title | Software tools and packages for electrophysiology and imaging |
Description | The laboratory continues to develop and refine software/hardware tools for data acquisition and analysis relevant to electrophysiology, single-cell imaging and analysis. These activities are long-standing and open-ended, and develop in line with the current research activities and needs of the laboratory. All software and related packages are made freely available to the research community through the laboratory website at psrg.org.uk |
Type Of Technology | Software |
Impact | The various software tools and packages have furthered the research activities of the laboratory since the 1990s and continue to provide key support and drivers for advancing much of current research. These tools and packages are disseminated, on average, to over 100 laboratories per year. |
URL | http://psrg.org.uk |
Description | International online services |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Prof. Blatt and members of his laboratory have contributed to various media events over the years, including online interview contributions (e.g. People behind the Science, a US-based media program) |
Year(s) Of Engagement Activity | Pre-2006,2006,2008,2011,2015,2016,2017,2018 |
Description | Invited presentations |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I regularly speak to audiences, from small groups (5-20) to large audiences (>1000) in a variety of settings. In addition to teaching and extramural activities associated with the university, I also speak on invitation to national and international groups a number of times each year and in a variety of settings, academic as well as public. I also reach audiences through short video presentations mounted on the web, these primarily via my laboratory website and the ASPB websites. Anyone reading this entry is welcome to visit these sites to learn more. The impacts arising from my presentations are varied. For example, a common consequence of my speaking in academic settings is to attract potential researchers to visit my laboratory and, frequently, to interest potential collaborators and students/postdocs to my research group. At scientific meetings, my talks often attract interest also from researchers interested in the various tools and materials that my research has produced, including the various vector systems and software packages that I |
Year(s) Of Engagement Activity | Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |
Description | Schools and displays |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | As these were multiple events, this question is not informative or useful. Participants varied from numbers in the tens to several thousands Extensive training of participating laboratory members as well as broad scope reach to schools and communities, in the case of the GCC science days to the west of Scotland and in the case of the IFPD activities to audiences within and outside the UK |
Year(s) Of Engagement Activity | 2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |
Description | Teaching Tools |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Schools |
Results and Impact | The PI has supported the editor in developing these tools since their inception in 2009 and has contributed to recent tools relating to membranes and transport education The Tool received an international award in 2010 for excellence in education and has an acknowledged takeup worldwide in over 3000 institutions |
Year(s) Of Engagement Activity | 2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |
Description | Teaching Tools |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Schools |
Results and Impact | The PI has supported the editor in developing these tools since their inception in 2009 and has contributed to recent tools relating to membranes and transport education The Tool received an international award in 2010 for excellence in education and has an acknowledged takeup worldwide in over 3000 institutions |
Year(s) Of Engagement Activity | 2009,2010,2011,2012,2013,2014,2015,2016,2017,2018 |
URL | http://psrg.org.uk |