In October 2015, researchers from around the world came together in Iguassu Falls, Brazil, for the Stress Resilience Symposium, organized by the Global Plant Council and the Society for Experimental Biology (SEB), to discuss the current research efforts in developing plants resistant to the changing climate. (See our blog by GPC’s Lisa Martin for more on this meeting!)
Building on the success of the meeting, the Global Plant Council team and attendees compiled a set of papers to provide a powerful call to action for stress resilience scientists around the world to come together to tackle some of the biggest challenges we will face in the future. These four papers were published in the Open Access journal Food and Energy Security alongside an editorial about the Global Plant Council.
In the editorial, the Global Plant Council team (Lisa Martin, Sarah Jose, and Ruth Bastow) introduce readers to the Global Plant Council mission, and describe the Stress Resilience initiative, the meeting, and introduce the papers that came from it.
In all of these papers, the authors suggest practical short- and long-term action steps and highlight ways in which the Global Plant Council could help to bring researchers together to coordinate these changes most effectively.
Edith, you have put a huge amount of work into uncovering the history of plant physiology research in Argentina. Why did you decide to do it and how did you undertake this challenge?
The current president of the SAFV, Pedro Sansberro, asked Alberto Golberg and myself if we would be willing to document the history of the society. Unaware of the tremendous task ahead, we agreed.
The information was scattered, so the first thing we did was try to collect as many SAFV conference books as possible. Sending requests through the SAFV mailing did not work, so it was essentially through personal contacts that we were able to put together the whole collection of conference books. It is now deposited in the library of CIAP (Centro de Investigaciones Agropecuarias – contact: firstname.lastname@example.org). People also sent the minutes of past meetings and pictures.
Initially we were only going to analyze the conference books and interview some plant scientists that were among the first disciples of the “founding fathers” of Argentinian experimental plant biology, but as we worked, our book grew and diversified.
What was the most interesting thing you discovered while writing the book?
It’s hard to narrow down which discovery was most exciting!
Victorio Trippi, one of the disciples of the “founding fathers”, told us that many researchers initially published in the journal Phyton, which was founded in Argentina in 1951. Our inspection of the archives of this publication yielded a lot of valuable information, and was an enlightening experience. We traced great names in Argentine plant science to the very beginning of their careers, looking at their topics of interest, how they moved from one job to another, and who their co-authors were. Even earlier than this though, we managed to trace the first mention of plant hormones in Argentina to a paper written by Guillermo Covas in 1939.
Writing the book was rewarding too, because we realized that plant physiology research has steadily grown in Argentina, judging by the participation in the conferences and the amount of research groups all over the country. It was very good to reveal the significant contributions that Argentine experimental plant science has made to many topics, such as photobiology, crop ecophysiology, germination physiology, senescence, mineral nutrition and carbohydrate metabolism, among others.
Why did you decide to include essays from the many groups researching plant physiology in Argentina?
We included them to reflect how much plant physiology has grown and diversified in Argentina. In the book we also invite those that did not have a chance to join this edition to contribute to a future one.
What words of wisdom did the researchers who were interviewed want to share with early career researchers for the future?
Most of them emphasized the need for team work, with people from different background joining forces to tackle a specific problem. The SAFV, they point out, has provided a friendly environment that has promoted collaboration and exchange of ideas among its members, and they hope this spirit will persist. They are moderately optimistic about the future, underscoring the need for new research paradigms both in the public and private sectors.
Carlos Ballaré underscored the human aspect of the history of the SAFV in his description of your book, printed on the cover. Could you elaborate on this?
Carlos meant that the book includes personal accounts from the people that have devoted their professional lives to plant physiology and ecophysiology, anecdotes of how the research groups developed and grew, and tales of how researchers replaced the lack of equipment with clever ideas. He highlights that the book has an emphasis on human endeavor, rather than being just a review of numbers, places, and dates.
Beyond the analysis of numbers and growth, the book reveals how early researchers worked on problems that largely sprang from their environment, attempting to understand the causes of issues that had an impact on crop productivity. Thus, those in Tucumán initially worked on sugar cane, those in Mendoza researched grapevines, and the focus in Buenos Aires was potatoes. As groups grew and diversified, this initial link was often blurred; young researchers joining ongoing work never realized what the initial question had been.
In a country where agricultural products or their derivatives still make a significant contribution to GDP, it is sensible to resume the link to local agricultural problems. For this task, it will be essential to adopt a systemic collaborative approach.
The authors of the book, Edith Taleisnik and Alberto Golberg.
As popular British botanist (and GPC blog guest) James Wong wrote in the UK’s Guardian newspaper earlier this year: “gardening is good for you”. Ask most people how they can benefit from gardening, and they might suggest improved physical activity or stress relief, but this is only scratching the surface.
The People Plant Council (PPC) is an international group of researchers and other industrial and not-for-profit partners, which aims to understand the effects plants have on our well-being. By communicating its findings to affiliates and the public, the PPC encourages the translation of these findings into health-enhancing programs. The PPC was established after a 1990 symposium entitled, “The Role of Horticulture in Human Well-Being and Social Development”, which identified a need for scientific research into the influence of horticulture on human health and quality of life.
The benefits of plants
The earliest reports of horticulture being used to improve human health come from ancient Egypt, where members of royalty were prescribed walks through the palace gardens as a treatment for mental illness (1). Today, research from the PPC and others has identified wide-ranging psychological, physiological, and sociological benefits from plants.
Gardening is good for both physical and mental health. Credit: Shyn Darkly. Used under license: CC BY 2.0.
The physiological benefits of gardening include an increase in physical activity (and the resulting improvements in cardiovascular fitness, muscle strength and aerobic capacity), but there are also some less obvious benefits, including better hand-eye coordination, balance, and an improvement in some chronic diseases. In one PPC-led study, elderly women took part in 50-minute gardening sessions twice a week, which led to significant improvements in their dexterity, muscle mass and cognitive ability compared to a control group (2).
There are also significant psychophysiological benefits to horticulture. Two interesting studies found that exposure to soil – or more precisely, to a common bacterium in soil (Mycobacterium vaccae) – improved the quality of life for both human cancer patients and mice by inducing the production of the brain’s “happy chemical”, seratonin (3,4). Contact with nature has also been shown to improve memory, concentration and stress.
People connect with each other around plants; whether it’s admiring a friend’s garden, giving a partner some flowers, or sharing a picnic at the local park, most of us have experienced the sociological benefits of plants. A PPC-led study found that horticulture was brilliant for improving peer relationships in schools too; a collaborative gardening program for small groups of 12–13 year-olds led to meaningful friendships that persisted after the class ended. The gardening students were also more law-abiding and social than the control group.
People bond over the experience of enjoying nature together. Credit: Amelia Wells. Used under license: CC BY 2.0.
At the IPPS meetings, delegates address the inherent impacts of nature on every aspect of our lives, including physical and mental health, and education. Dr Park elaborated, “The IPPS is attended by researchers, practitioners (such as horticultural therapists), and educators in various fields such as horticultural science, ethnobotany, psychology, nursing, occupational therapy, etc. The International Society for Horticultural Science supports the PPC, and enables us to publish the IPPS proceedings in their journal, Acta Horticulturae”.
This week we spoke to Professor Neil Bruce, whose research at the University of York (UK) focuses on metabolic pathways. His insights into the detoxification of pollutants by plants and microorganisms has led to promising new solutions to help clean up polluting explosives from military testing.
Could you begin by telling us a little about your research interests?
I have very broad research interests that often revolve around finding enzymes for biotechnological applications. A particular focus of my lab is the biochemistry and molecular genetics of plant and microbial metabolism of xenobiotic (foreign) compounds, such as environmental pollutants. Elucidating these metabolic pathways often results in the discovery of new enzymes that catalyze interesting chemistries. Being a biologist at heart, I’m interested in the evolutionary origin of these enzymes, but also by studying their structure and function I’m exploring how these enzymes can be engineered to further improve their properties for a particular application, such as environmental remediation or biocatalysis.
You spoke at the GARNet 2016 meeting about engineering plants to remediate explosives pollution. Could you explain what this problem is and how it affects both people and the environment?
Explosive compounds used in munitions are highly toxic and the potential for progressive accumulation of such compounds in soil, plants, and groundwater is a significant concern at military sites. It is estimated that in the US alone, 10 million hectares of military land is contaminated with components of munitions. The explosives mainly used in artillery, mortars and bombs are 2,4,6-trinitrotoluene (TNT) and Composition B (containing TNT and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)). The US Department of Defense estimated that the clean-up of unexploded ordnance, discarded military munitions and munition constituents on its active ranges would cost between $16 billion and $165 billion. Explosives pollution is, however, a global problem, with large amounts of land and groundwater contaminated by TNT and RDX, including polluted sites in the UK that date back to the First and Second World Wars. Explosives pollution will continue to be a pressing issue while there is a requirement for military to train and the existence of armed conflict requires munitions to be manufactured. There is an urgent need to develop sustainable in situ technologies to contain and treat these pollutants.
TNT is toxic to plants because of the actions of an enzyme called monodehydroascorbate reductase, which breaks TNT down into a toxic form. Plants lacking this enzyme, such as the mdhar6 mutant plants on the right, can grow very well on TNT-polluted soil. Credit: Johnston et al. (2015).
How did you develop the idea of using plants to remove explosives pollution? What benefits do plants have over the microorganisms from which the enzymes are obtained?
We have worked closely with the UK Ministry of Defence and US Army to understand the fate of explosives in the environment. Knowledge of their effects on biological systems is important, as this information can be used to support the management of contaminated sites. We have, therefore, been uncovering the molecular mechanisms behind these detoxification processes in plants, and have used this knowledge, in combination with studies on the bacterial degradation of pollutants, to successfully engineer transgenic plants able to remediate toxic explosive pollutants in a process called ‘phytoremediation’.
An innovative aspect of our work has been the use of genetic engineering to combine the biodegradative capabilities of explosives-degrading bacteria with the high biomass, stability and detoxification systems inherent in plants. While it is possible to find explosives-degrading bacteria on polluted land, they do not degrade the explosives fast enough to prevent leaching into the groundwater. Our engineered transgenic plant systems, however, can efficiently remove toxic levels of TNT and RDX from contaminated soil and water.
You mentioned that you are currently testing transgenic switchgrass to remove RDX and TNT pollution in the US. Why did you choose this species and have you considered developing other species suited to different environments?
Plants appropriate for the phytoremediation of explosives need to be adaptable to conditions on military ranges, for example, they need good fire tolerance, and to be able to grow over a wide geographical range. Switchgrass meets these criteria, and is also deep-rooting, can be grown on marginal lands, and researchers can benefit from established methods for genetically engineering switchgrass. We have also been engineering other grass species and have considered fast-growing deep-rooting trees such as poplar.
In a poetic twist, rather than turning fertilizers into explosives, Professor Bruce’s phytoremediating plants convert explosives into fertilizer. Credit: Neil Bruce.
How quickly can engineered plants remove this pollution?
In the lab these plants can remove levels of explosives pollution found in the environment within a matter of days. We are currently carrying out field trials with our transgenic plants on a military site in the US, to observe their phytoremediation effectiveness in the real world. If these trials are successful, a number of demonstration studies on contaminated sites will be required to convince end users of the benefits of phytoremediation for remediating and maintaining military land. These demonstration studies will also allow us to evaluate any risks, which will be important to obtain further approval from the US Department of Agriculture to be able to use these plants on a larger scale.
What other projects are you working on? Could you elaborate on any recent discoveries?
As well as explosives, we are also working on the use of plants to extract platinum group metals (PGMs) from mining waste. PGMs are used in an ever-expanding array of technologies and demand is spiralling upwards; however, these are rare and expensive to mine. It is essential that these metal reserves are utilized and recycled responsibly, not dispersed and lost into the environment. Plants can take up metals from their environment and, in the case of PGMs, can deposit them as nanoparticles within their tissues. Importantly, we have recently shown that plants containing palladium nanoparticles can also be used to make efficient biocatalysts, and we are currently using synthetic biology in plants to improve palladium uptake and nanoparticle formation.