A multidisciplinary, international team, has uncovered a new biochemical mechanism fundamental to plant life. Their research details the discovery of the enzymatic reaction involving carbohydrates present in plant cell walls, which are essential for their structure.
Miniscule plants growing on desert soils can help drylands retain water and reduce erosion, researchers have found. A global meta-analysis led by UNSW scientists shows tiny organisms that cover desert soils—so-called biocrusts—are critically important for supporting the world’s shrinking water supplies.
In a world first, researchers have discovered a plant that has successfully evolved to use ants—as well as native bees—as pollinating agents by overcoming their antimicrobial defenses.
New research has heralded a promising step for sufferers of wheat sensitivity or allergy. A project has revealed key insights about the proteins causing two of the most common types of wheat sensitivity — non-coeliac wheat sensitivity (NCWS) and occupational asthma (baker’s asthma).
A group of scientists from Sechenov University, Russia, and La Trobe University, Australia, have developed a fast and cost-effective method of detecting and identifying bioactive compounds in complex samples such as plant extracts. They successfully applied the method to examine Mediterranean and Australian native culinary herbs. Three articles on this work were published in Applied Sciences, Journal of Pharmaceutical and Biomedical Analysis and Journal of Chromatography A.
Since ancient times, people have been using herbs as food additives and medicines, though a search for useful compounds and a study of their properties remain a difficult task. It is possible to examine a compound if it is stable enough and can be separated from other substances in a sample. However, plant extracts contain hundreds of compounds. In the past, only known compounds were investigated by target analysis and most bioactive compounds were left undiscovered. Thus, the number of compounds that are yet to be explored is so huge that methods that can both screen mixtures and identify the compounds responsible for bioactivity are of greater value.
The authors of the papers used an Effect Directed Analysis (EDA) approach, which is a combination of chromatographic separation with in situ (bio)assays and physico-chemical characterisation to discover and identify bioactive compounds in complex plant samples. Thin-layer chromatography (TLC) and high performance thin-layer chromatography (HPTLC) are well established, chromatographic separation techniques ideally suited for high-throughput screening of bioactive compounds in crude samples.
To separate substances, TLC uses the fact that various compounds are transported by a solvent and absorbed by a sorbent at different speeds. A sorbent-coated plate with a studied mixture is immersed with one end in the solvent, and under the action of capillary forces, it begins to rise along the plate, taking the substances of the mixture with it. As they move upward, the compounds are absorbed by the sorbent and remain as horizontal bands that can be distinguished in visible, infrared or ultraviolet light. Using this method, crude extracts can be analysed directly with no preparation and possible loss of sample components.
Bioassays allow to determine the properties of compounds, such as toxicity, observing how model organisms (bacteria, plants or small animals) react to them. In this way, one can select extracts able to inhibit the action of individual enzymes or reactive oxygen species.
Combination of TLC chromatography with microbial (bacteria and yeast) tests and biochemical (enzyme) bioassays enables rapid and reliable characterization of bioactive compounds directly on the chromatographic plates, without isolation/extraction. The advantage of HPTLC is that plates/chromatograms can be directly immersed into enzyme solution (bioassays), incubated for up to several hours, followed by visualization of the (bio)activity profile via an enzyme substrate reaction as bioactivity zones. This approach is more cost effective, enabling a more streamlined method to detect and characterise natural products that are suitable candidates for further investigation as potential new drug molecules.
Using this method, scientists examined the properties of bioactive compounds from culinary herbs commonly used in the Mediterranean diet: basil, lavender, rosemary, oregano, sage and thyme. Australia’s native plants were added to the list: lemon myrtle (Backhousia citriodora), native thyme (Prostanthera incisa), sea parsley (Apium prostratum), seablite (Suaeda australis) and saltbush (Atriplex cinerea). Some of the secondary metabolites from these plants exhibit significant antioxidant activity and enzyme inhibition, like α-amylase inhibition. Therefore, these herbs may be preventive not only against cardiovascular diseases but also type 2 diabetes. The enzyme α-amylase breaks down polysaccharides, thereby increasing blood sugar levels. Recent studies suggest that hyperglycemia induces generation of reactive oxygen species, alteration of endogenous antioxidants and oxidative stress. It was found that patients with uncontrolled sugar levels in addition to diabetes also suffer from accelerated cognitive decline independent of their age. Although Australian native herbs are used as a substitute for related European plants, their medicinal properties are much less studied.
After preparing the extracts, the scientists began to study their composition and qualities. Rosemary and oregano extracts showed the greatest antioxidant activity, while sage, oregano and thyme were the best at slowing down reactions involving α-amylase (extracts from lavender flowers and leaves were the only ones not to show this effect). Among the studied Australian native herbs, lemon myrtle showed the strongest antioxidant properties, with the best α-amylase inhibition observed with extracts of native thyme (this property was noticed for the first time), sea parsley and saltbush.
The study of plant extracts using bioassay and thin-layer chromatography allows scientists to examine a variety of compounds, find mixtures that have the desired properties and isolate substances that exhibit them to the greatest extent. This fast and cost-effective method will be useful for finding new drug compounds.
Article source: Sechenov University via Eurekalert
Alert: Teachers of plant physiology!
Have you ever wanted a free, on-line textbook written by experts and regularly updated?
Plants in Action is an on-line resource for students and academics teaching plant function to undergrads, published by the Australian and New Zealand societies of plant science. Each chapter has up to 100 illustrations suitable for Powerpoint presentations. It is also ideal for graduate students and post-docs in molecular biology looking for the whole-plant context for their work. Of the original 20 chapters, ten have been fully revised.
Could you begin by describing the Plants in Action (PiA) textbook and how the idea first came about?
The original editors and contributors produced a textbook on plant function that used examples from the southern hemisphere, with view of adaptations in nature to performance in cultivation. They were motived to communicate the strong plant science in Australia and New Zealand. PiA was born as a textbook in 1999, and ten years later went open-access and free online.
Who are your target audience?
Undergraduate students, educators, practitioners and researchers, and others interested in plants and how they function. PiA gets thousands of hits per day from around the globe, including developing countries.
What topics do you cover?
To the best of my knowledge, PiA is the only comprehensive plant science textbook with a southern hemisphere perspective. It covers molecular, cellular, and whole-plant function, in ecophysiology and vegetation-environment interactions, from Antarctica to the tropics. PiA features plants that are some of the best studied genetic models and crops, as well as wild plants.
Who has contributed to the textbook, and how did you enlist potential collaborators?
PiA was written by Australian and New Zealand plant scientists from a range of institutions, many of whom have worked on both editions. Chief Editor Dr Rana Munns and the chapter editors find new contributors if the original authors are not available, although occasionally authors volunteer contributions
What changes have you made in the second edition, and how are the revisions coming along?
PiA2 is being updated to reflect recent advances in plant science, and has a new look as software enables ever more attractive layouts, with no limit for images and illustrations. PiA can be read online and is easily printed, which is important for internet-challenged regions and for students wanting to add notes. Ten chapters are fully updated with several chapters expanded.
Revisions can be made instantly (as a wiki) but take a little longer if the expert skills of our IT assistants are required. Complete revisions of chapters are slower to come on board.
Encouragingly, some excellent contributions have recently been made by junior scientists who see a strong value in developing an open-access resource to share their expertise widely.
You mentioned the text can be translated into different languages. How might users go about getting a textbook in their native language?
The project is sponsored by the Australian and New Zealand societies of plants scientists, ACIAR, and the University of Queensland. Could you elaborate on how this funding was acquired, if possible?
ACIAR (Australian Centre for International Agricultural Research) was our first sponsor. They saw the value of an open-access resource, particularly for plant biologists in developing countries and the free exchange of knowledge. The University of Queensland (UQ) came on board to provide the host server as PiA supports teaching at UQ with strengths in agriculture and environmental science. Sponsorship was also provided by the Western Sydney University, the University of Western Australia, and the Australian Centre for Plant Functional Genomics. The societies of plant science in Australia and New Zealand are ongoing supporters and PiA remains predominantly the product of their members.
Are you looking to expand on the work in the future? How can potential contributors get involved?
It would be marvelous to have a person with time and expertise to develop further materials to add to PiA2 in collaboration with editors, authors, educational designers, and students. This could include material specifically designed for schools and interactive learning tools for students of all levels. We welcome all contributors (irrespective of their connections to the plant societies), and they can contact Rana or any chapter editor.
Without plants, Earth would not give us habitat, food and materials. But with 25% of the global flora threatened with extinction, we need more people to understand plants, and what we need to do protect them and their habitats.
The first edition of Plants in Action was published by the Australian and New Zealand societies of plant science as a hardcover book in 1999, which is also now free on-line (http://plantsinaction.science.uq.edu.au/edition1/).
All images are courtesy of the Plants in Action team, and are used with permission.
Here at the Global Plant Council (GPC) we’re big fans of social media
– we’re even helping to develop a new social media platform just for plant scientists! As well as this blog, we also have two Twitter accounts: our main, English-language account is at @GlobalPlantGPC, to which myself (@lisaamartin1), Ruth (@plantscience), and GPC New Media Fellows Amelia (@) and Sarah (@josesci) all contribute. Alternatively, if you speak Spanish we also have a Spanish-language account at @GPC_EnEspanol (operated by Ecuadorian-PhD-student-in-Germany Juan-Diego Santillana-Ortiz; @yjdso, who kindly translates our tweets).
We find Twitter a great way to share links, news, journal articles and conference updates, while also networking with the global plant science community. Join over 1000 other plant scientists and enthusiasts and follow us, if you’re not already!
If you’re not sure where to start with Twitter, Mary Williams from ASPB (@PlantTeaching) has written a great two-part blog (we feature in Part 1! And here’s Part 2) that will help you get started and understand the ‘twetiquette’ of tweeting, especially from conferences.
However, we’ve never had a Facebook page – until now!
Although Facebook is by far the most popular social networking site across the globe, the way we use it has evolved dramatically since its inception in 2004. ‘Thefacebook’ as it was first known, was famously founded by Harvard University student Mark Zuckerberg as a way for his fellow students to view and comment on photographs of their dorm-mates. Initially restricted to Harvard, the website soon expanded to universities across the US, then the world, and now almost anyone can use it, even without an academic email address.
But Facebook has moved on from its early days and it’s now not all about ‘poking’ your friends (remember that?!). Now worth billions of dollars, Facebook has morphed into an all-encompassing platform for both recreation and business. While many people still use Facebook to keep in touch with friends and family, share photos and status updates, it’s also increasingly being used to share news, articles and opinions, to play games, form groups or communities, and as a tool for companies and organizations to interact with and advertise to customers or members.
At the Society for Experimental Biology conference in Prague in June, I heard several scientists extolling the benefits of social media, particularly – and perhaps unsurprisingly – in the Education and Outreach sessions. I was particularly interested to repeatedly hear the message that Facebook is a very useful tool for science communication and outreach – so we’ve decided to try it!
Why bother with Facebook as well as other social media channels?
Having only ever used Facebook for personal uses, Sarah and I asked some prolific social media users for their advice on starting and using a Facebook page, and in answer to the question, “Why should we bother with Facebook?”, the overwhelming message was clear: Facebook is used by more, different people.
Compared to Twitter, which has around 316 million users, Facebook reached its 1 billionth account in 2012, and while the people we spoke to find that most of their Twitter followers are from English-speaking countries, their Facebook visitors represent a much broader range of geographic locations and languages. Furthermore, unlike setting up and maintaining a website, it’s free to set up Facebook pages or groups, so some organizations only exist on social media. By setting up a Facebook page for the GPC, we should, in theory, be able to interact with more people than we would with just our Twitter accounts and blog, thus we will be able to share and promote plant science all over the world more effectively and to a greater diversity of people.
If you’re a Facebook user, please go to www.facebook.com/GlobalPlantGPC and give us a ‘like’!
If you’re attending our SEB Plant Section Symposium on Stress Resilience, you can also let us know by joining our Facebook event! (Please note however, that saying you’re coming to the meeting on Facebook is not the same as registering! You’ll need to do that here.)
Here’s a list of some of our Member Organizations who also have a presence on Facebook. Let us know if there are any other pages we should ‘like’! We’re also interested to hear from you if you have any thoughts about using social media, or suggestions of content you would like to see on Facebook. How do you use Twitter and Facebook, and how does your use of these channels differ, if at all? Please comment below!
GPC Member Organizations on Facebook
- American Society of Agronomy
- American Society of Plant Biologists
- Argentinean Society of Plant Physiology/Sociedad Argentina de Fisiologia Vegetal
- Australian Society of Plant Biologists
- Brazilian Society of Plant Physiology/Sociedade Brasileira de Fisiologia Vegetal
- Crop Science Society of America
- European Plant Science Organisation
- Federation of European Societies of Plant Biology
- Scandinavian Plant Physiology Society (Education Committee)
- Society for Experimental Biology