Striga hermonthica – a beautiful but devastating plant…

This week’s post was written by Caroline Wood, a PhD candidate at the University of Sheffield.

When it comes to crop diseases, insects, viruses, and fungi may get the media limelight but in certain regions it is actually other plants which are a farmer’s greatest enemy. In sub-Saharan Africa, one weed in particular – Striga hermonthica – is an almost unstoppable scourge and one of the main limiting factors for food security.

Striga is a parasitic plant; it attaches to and feeds off a host plant. For most of us, parasitic plants are simply harmless curiosities. Over 4,000 plants are known to have adopted a parasitic mode of life, including the seasonal favorite mistletoe (a stem parasite of conifers) and Rafflesia arnoldii, nicknamed the “corpse flower” for its huge, smelly blooms. Although the latter produces the world’s largest flower, it has no true roots – only thread-like structures that infect tropical vines.

When parasitic plants infect food crops, they can turn very nasty indeed. Striga hermonthica is particularly notorious because it infects almost every cereal crop, including rice, maize, and sorghum. Striga is a hemiparasite, meaning that it mainly withdraws water from the host (parasitic plants can also be holoparasites, which withdraw both water and carbon sugars from the host). However, Striga also causes a severe stunting effect on the host crop (see Figure 1), reducing their  yield to practically nothing. Little wonder then, that the common name for Striga is ‘witchweed’.

Striga-infected sorghum

Figure 1: Striga-infected sorghum. Note the withered, shrunken appearance of the infected plants. Image credit: Joel Ransom.

 

Several features of the Striga lifecycle make it especially difficult to control. The seeds can remain dormant for decades and only germinate in response to signals produced by the host root (called strigolactones) (Figure 2). Once farmland becomes infested with Striga seed, it becomes virtually useless for crop production. Germination and attachment takes place underground, so the farmer can’t tell if the land is infected until the parasite sends up shoots (with ironically beautiful purple flowers). Some chemical treatments can be effective but these remain too expensive for the subsistence farmers who are mostly affected by the weed. Many resort to simply pulling the shoots out as they appear; a time-consuming and labor-intensive process. It is estimated that Striga spp. cause crop losses of around US $10 billion each year [1].

Certain crop cultivars and their wild relatives show natural resistance to Striga. Here at the University of Sheffield, our lab group (headed by Professor Julie Scholes) is working to identify resistance genes in rice and maize, with the eventual aim of breeding these into high-yielding cultivars. To do this, we grow the host plants in rhizotrons (root observation chambers) which allow us to observe the process of Striga attachment and infection (see Figure 3). Already this has been successful in identifying rice cultivars that have broad-spectrum resistance to Striga, and which are now being used by farmers across Africa.

 

Life cycle of Striga

Figure 2: Life cycle of Striga spp. A single plant produces up to 100,000 seeds, which can remain viable in the soil for 20 years. Following a warm, moist conditioning phase, parasite seeds become responsive to chemical cues produced by the roots of suitable hosts, which cause them to germinate and attach to the host root. The parasite then develops a haustorium: an absorptive organ which penetrates the root and connects to the xylem vessels in the host’s vascular system. This fuels the development of the Striga shoots, which eventually emerge above ground and flower. Figure from [2].

 

But many fundamental aspects of the infection process remain almost a complete mystery, particularly how the parasite overcomes the host’s intrinsic defense systems. It is possible that Striga deliberately triggers certain host signaling pathways; a strategy used by other root pathogens such as the fungus Fusarium oxysporum. This is the focus of my project: to identify the key defense pathways that determine the level of host resistance to Striga. It would be very difficult to investigate this in crop plants, which typically have incredibly large genomes, so my model organism is Arabidopsis thaliana, the workhorse of the plant science world, whose genome has been fully sequenced and mapped. Arabidopsis cannot be infected by Striga hermonthica but it is susceptible to the related species, Striga gesnerioides, which normally infects cowpea.  I am currently working through a range of different Arabidopsis mutants, each affected in a certain defense pathway, to test whether these have an altered resistance to the parasite.  Once I have an idea of which plant defense hormones may be involved (such as salicylic acid or jasmonic acid), I plant to test the expression of candidate genes to decipher what is happening at the molecular level.

Striga-infected Arabidopsis

Figure 3: One of my Arabidopsis plants growing in a rhizotron. Preconditioned Striga seeds were applied to the roots three weeks ago with a paintbrush. Those that successfully attached and infected the host have now developed into haustoria. The number of haustoria indicates the level of resistance in the host. Image credit: Caroline Wood.

 

It’s early days yet, but I am excited by the prospect of shedding light on how these devastating weeds are so effective in breaking into their hosts. Ultimately this could lead to new ways of ‘priming’ host plants so that they are armed and ready when Striga attacks. It’s an ambitious challenge, and one that will certainly keep me going for the remaining two years of my PhD!

 

You can follow my journey by reading my blog and keeping up with me on Twitter (@sciencedestiny).

 

References:

[1] Westwood, J. H. et al. (2010). The evolution of parasitism in plants. Trends in Plant Science, 15(4): 227-235.

[2] Scholes, J. D. and Press, M. C. (2008). Striga infestation of cereal crops – an unsolved problem in resource limited agriculture. Current Opinion in Plant Biology, 11(2): 180-186.

Sustainable, resilient, and nutritious food production with N8 AgriFood

This week we spoke with Dr Sally Howlett, a Knowledge Exchange Fellow with the N8 AgriFood Programme. (More on Sally at the end).

Sally, what is the N8 AgriFood Programme? When and why was it established?

The N8 Research Partnership is a collaboration of the eight most research-intensive universities in the North of England, namely Durham, Lancaster, Leeds, Liverpool, Manchester, Newcastle, Sheffield, and York. It is a not-for-profit organization with the aim of bringing together research, industry and society in joint initiatives. These partners have a strong track record of working together on large-scale, collaborative research projects, one of which is the N8 AgriFood Programme. This £16M multi-disciplinary initiative is funded by the N8 partners and HEFCE (The Higher Education Funding Council for England), and was launched in 2015 to address three key global challenges in Food Security: sustainable food production, resilient food supply chains, and improved nutrition and consumer behavior.

How does plant science research fit into the N8 AgriFood Programme?

There is a strong motivation to ‘think interdisciplinary’ when it comes to developing projects for the N8 AgriFood Programme; therefore, whilst the most obvious home for plant science may be within the theme of sustainable food production, e.g. crop improvement, we see no boundaries when it comes to integrating fundamental research in plant science with applications in all three of our research themes. The testing of research ideas in the ‘real world’ is supported by the five University farms within the N8, which include arable and livestock holdings.

We are launching a Crop Innovation Pipeline to assist with the translation of research into practical applications, with the first event taking place in Newcastle on 2nd-3rd May 2017. It is an opportunity for scientists from academia and industry and representatives from the farming community to discuss their ideas for the implementation of plant biology research into on-farm crop improvement strategies.

How is the work split between the different institutions? How is such a large-scale initiative managed?

Whilst there are many areas of shared expertise between the eight partner institutions, each also has its own areas of specialism within the agri-food arena. The strength of the N8 AgriFood Programme is in working collaboratively to identify complementary strengths and grow those areas in a synergistic way. In this way, we are collectively able to tackle research projects that would not be possible for a single university alone. Pump-priming funds are available at a local and strategic level to support this kick-starting of new multi-institution projects. The Programme itself is led out of the University of York, and each University has its own N8 AgriFood Chair in complementary areas across the Programme. Having both inward- and outward-facing roles, they work with the Knowledge Exchange Fellows and the Programme Lead for each theme to ensure activities at their own institute are connected with what is going on in the wider N8.

What does your work as a Knowledge Exchange Fellow entail?

As a Knowledge Exchange Fellow within the N8 AgriFood Programme, my initial contact with people usually begins with the question ‘What on earth does a Knowledge Exchange Fellow do?’ – and it can be quite difficult to answer! Although some form of knowledge transfer activity has been a defined output of research projects for some time now, knowledge exchange as an ongoing two-way dialogue between researchers and external stakeholders to enable a co-creation process has been less common until recently. Hence dedicated Knowledge Exchange Fellows with academic training are a relatively ‘new’, but growing, phenomenon.

My role is best described as acting as a bridge between the research community and non-academics with a vested interest in developing or using the findings of the research process. It is key to have a good understanding of the perspectives of all parties involved and be able to translate this into the appropriate language for a particular sector. Each of the N8 institutes has appointed Knowledge Exchange Fellow(s), and we work as a cohort to keep abreast of the latest developments in our fields in order to support the development of relationships and innovative projects. In such a huge undertaking, the phrase ‘there is strength in numbers’ is certainly apposite!

 

How does N8 AgriFood interact with companies?

N8 Agrifood engages with UK-based companies in many ways, including individual face-to-face meetings, attending and hosting networking events, participating in national exhibitions, and holding business-facing conferences. We also run a series of Industry Innovation Forums on various topics throughout the year. These provide a unique opportunity to discuss key challenges, identify problems and deliver new insights into innovation for agri-food, matching practical and technical industry challenges with the best research capabilities of the N8 universities.

 

How does N8 Agrifood interact with farmers?

As the engine of the agri-food industry, the views and collective experience of the farming community are vitally important in shaping the direction and content of the projects we develop. Co-hosting events with programs such as the ADAS Yield Enhancement Network (YEN), which involves over 100 farms, is one way that we connect with the sector. We are also working with agricultural societies to promote what we are doing and engage directly with their networks of farming members, e.g. the Yorkshire Agricultural Society’s Farmer Scientist Network. Last year we gave a series of seminars at the Great Yorkshire Show and are keen to encourage further collaboration with practicing farmers and growers across the UK.

 

Does N8 AgriFood collaborate with other research institutes around the world?

The N8 AgriFood Programme has strong international connections and actively welcomes working with international research institutes. Given the interconnectedness of our global food system, we feel that it is vital to link with overseas partners and that real impact can be had by bringing together top researchers from other countries to work together on problems. The value of N8 AgriFood as a one-stop shop is that we represent a large breadth and depth of expertise under a single umbrella, which greatly facilitates collaborating and finding suitable collaboration partners. Our pump-priming funds are a way for researchers to initiate new international partnerships, and we are also working to build links with global research organizations who have shared interests. For example, we recently visited Brazil and China to explore specific opportunities for collaboration and leveraging of research expertise and facilities, and are currently organizing a workshop in Argentina in March.

 

Where can readers get more information?

If you’d like to find out more, please visit our website: http://n8agrifood.ac.uk/, or consider attending one of our upcoming events:

 

All images are credited to the N8 Agrifood Programme.


Dr Sally Howlett is a Knowledge Exchange Fellow with the N8 AgriFood Programme. Her research background is in sustainable crop production and plant pest management.  After working on the control of invertebrate crop pests in New Zealand for several years, she returned to on-farm research in the UK and extended her focus to include the crops themselves taking a whole-systems view and comparing performance under conventional, organic and agroforestry management approaches. Sally’s role within N8 AgriFood provides a great opportunity to use her experience of agriculture and working with different actors across the sector to engage with external stakeholders, co-producing ideas and multi-disciplinary projects with applications throughout the agrifood chain.

Cassava brown streak: lessons from the field

This week’s post was written by Katie Tomlinson, a PhD student at the University of Bristol, UK, who spent three months as an intern at the National Crops Resource Research Institute in Uganda. She fills us in on the important research underway at the Institute, and how they communicate their important results to local farmers and benefit rural communities.  

Over the summer, I had a great time at the National Crops Resources Research Institute (NaCRRI) in Uganda. I’m currently in the second year of my PhD at the University of Bristol, UK, where I’m researching how the cassava brown streak disease (CBSD) viruses are able to cause symptoms, replicate and move inside plants. I was lucky enough to be given a placement at NaCRRI as part of the South West Doctoral Training Partnership Professional Internship for PhD Students (PIPS) scheme, to experience the problem for myself, see the disease in the field, meet the farmers affected and investigate the possible solutions.

 

Cassava brown streak disease

Cassava brown streak disease symptoms on tubers. Image credit: Katie Tomlinson.

 

Cassava is a staple food crop for approximately 300 million people in Africa. It is resilient to seasonal drought, can be grown on poor soils and harvested when needed. However, cassava production is seriously threatened by CBSD, which causes yellow patches (chlorosis) to form on leaves and areas of tubers to die (necrosis), rot and become inedible.

Despite being identified in coastal Tanzania 80 years ago, CBSD has only been a serious problem for Uganda in the last 10 years, where it was the most important crop disease in 2014–2015. The disease has since spread across East Africa and threatens the food security of millions of people.

NaCRRI is a government institute, which carries out research to protect and improve the production of key crops, including cassava. The focus is on involving farmers in this process so that the best possible crop varieties and practices are available to them. Communication between researchers and farmers is therefore vital, and it was this that I wanted to assist with.

 

Scoring cassava brown streak disease

Scoring cassava plants for Cassava brown streak symptoms. Image credit: Katie Tomlinson.

 

When I arrived I was welcomed warmly into the root crop team by the team leader Dr Titus Alicai, who came up with a whole series of activities to give me a real insight into CBSD. I was invited to field sites across Uganda, where I got to see CBSD symptoms in the flesh! I helped to collect data for the 5CP project, which is screening different cassava varieties from five East and Southern African countries for CBSD and cassava mosaic disease (CMD) resistance. I helped to score plants for symptoms and was fascinated by the variability of disease severity in different varieties. The main insight I gained is that the situation is both complex and dynamic, with some plants appearing to be disease-free while others were heavily infected. There are also different viral strains found across different areas, and viral populations are also continually adapting. The symptoms also depend on environmental conditions, which are unpredictable.

I also got to see super-abundant whiteflies, which transmit viruses, and understand how their populations are affected by environmental conditions. These vectors are also complex; they are expanding into new areas and responding to changing environmental conditions.

It has been fascinating to learn how NaCRRI is tackling the CBSD problem through screening different varieties in the 5CP project, breeding new varieties in the NEXTGEN cassava project, providing clean planting material and developing GM cassava.

 

Tagging cassava plants

Tagging cassava plants free from Cassava brown streak disease for breeding. Image credit: Katie Tomlinson.

 

And there’s the human element…

In each of these projects, communication with local farmers is crucial. I’ve had the opportunity to meet farmers directly affected, some of whom have all but given up on growing cassava.

 

Challenging communications

Communicating has not been easy, as there are over 40 local languages. I had to adapt and learn from those around me. For example, in the UK we have a habit of emailing everything, whereas in Uganda I had to talk to people to hear about what was going on. This is all part of the experience and something I’ll definitely be brining back to the UK! I’ve had some funny moments too… during harvesting the Ugandans couldn’t believe how weak I was; I couldn’t even cut one cassava open!

 

Real world reflections

I’m going to treasure my experiences at NaCRRI. The insights into CBSD are already helping me to plan experiments, with more real-world applications. I can now see how all the different elements (plant–virus–vector–environment–human) interact, which is something you can’t learn from reading papers alone!

Working with the NaCRRI team has given me the desire and confidence to collaborate with an international team. I’ve formed some very strong connections and hope to have discussions about CBSD with them throughout my PhD and beyond. It’s really helped to strengthen collaborations between our lab work in Bristol and researchers working in the field on the disease frontline. This will help our research to be relevant to the current situation and what is happening in the field.

 

Some of the NaCRRI team

Saying goodbye to new friends: Dr. Titus Alicai (NaCRRI root crops team leader), Phillip Abidrabo (CBSD MSc student) and Dr. Esuma Williams (cassava breeder). Image credit: Katie Tomlinson.

 

Plantwise – promoting and supporting plant health for the Sustainable Development Goals

Andrea Powell

Andrea Powell, CABI

Promoting and supporting plant health will be an important part of how we achieve the United Nations’ Sustainable Development Goals (SDGs). Andrea Powell, Chief Information Officer of the Centre for Agriculture and Biosciences International (CABI) looks at how the CABI-led Plantwise programme is helping to make a difference.

By Andrea Powell

 

On 26th and 27th July 2016, CABI held its 19th Review Conference. This important milestone in the CABI calendar saw our 48 member countries come together to agree a new medium-term strategy. As always, plant health was a key focus to our discussions, cutting across many of CABI’s objectives. For CABI, with 100 years of experience working in plant health, it has become one of our most important issues, upon which our flagship food security program, Plantwise, has been built.

Plant health can, quite simply, change the lives and livelihoods of millions of people living in rural communities, like smallholder farmers. Human and animal health make headlines, while plant health often falls under the radar, yet, it is crucial to tackling serious global challenges like food security. Promoting and supporting plant health will be an important way to achieve the Sustainable Development Goals (SDGs).

Plant health and the SDGs

Take, for example, SDG 1, which calls for ‘no poverty’. The UN states that one in five people in developing regions still lives on less than $1.25 a day. We know that many of these people are smallholder farmers. By breaking down the barriers to accessing plant health knowledge, millions of people in rural communities can learn how to grow produce to sell to profitable domestic, regional and international markets.

Plantwise ReportSDG 2 focuses on achieving ‘zero hunger’. Almost one billion people go hungry and are left malnourished every day – and many are children. Subsistence farmers, who grow food for their families to eat, can be left with nothing when their crops fail. Access to plant health knowledge can help prevent devastating crop losses and put food on the table.

Interestingly, SDG 17 considers ‘partnerships for the goals’ and is critical to the way in which we can harness and share plant health knowledge more widely to help address issues like hunger and poverty. By themselves, individual organizations cannot easily resolve the complicated and interconnected challenges the world faces today. This is why partnership is at the heart of CABI’s flagship plant health programme: Plantwise.

What is Plantwise?

Plantwise Report 2015

Since its launch in 2011, the goal of Plantwise has been to deliver plant health knowledge to smallholder farmers, ensuring they lose less of what they grow. This, in turn, provides food for their families and improves living conditions in rural communities. Plantwise provides support to governments, helping to make national plant health systems more effective for the farmers who depend on them. Already, Plantwise has reached nearly five million farmers. With additional funding, and by developing new partnerships, we aim to bring relevant plant health information to 30 million farmers by 2020, safeguarding food security for generations to come.

Plantwise ‘plant clinics’ are an important part of the fight against crop losses. Established in much the same way as clinics for human health, farmers visit the clinics with samples of their sick crops. Plant doctors diagnose the problem, making science-based recommendations on ways to manage it. The clinics are owned and operated by over 200 national partner organizations in over 30 countries. At the end of 2015, nearly five thousand plant doctors had been trained.

Plantwise

A Plantwise plant clinic in action. Credit: Plantwise

Harnessing technology for plant health

The Plantwise Knowledge Bank reinforces the plant clinics. Available in over 80 languages, it is an online and offline gateway to plant health information, providing the plant doctors with actionable information. It also collects data about the farmers, their crops and plant health problems. This enables in-country partner organizations to monitor the quality of plant doctor recommendations; to identify new plant health problems – often emerging due to trade or climate change issues; and develop new best-practice guidelines for managing crop losses.

Plantwise

The first ever e-plant clinic, held in Embu Market, Kenya. Credit: Plantwise

The Plantwise flow of information improves knowledge and helps the users involved: farmers can receive crop management advice, and researchers and governments can access data from the field. With a new strategy for 2017–19 agreed, CABI will continue to focus on building strong plant health systems. We are certain that plant health is of central importance to achieving the SDGs and, together in partnership, we look forward to growing the Plantwise program and making a concrete difference to the lives of smallholder farmers.

“A few years ago, I would make ZMW 5000 per year. Last year I got 15 000. I have never missed any plant clinic session. I’ve been very committed, very faithful, because I have seen the benefits.”––Kenny Mwansa, Farmer, Rufunsa District, Zambia.

Take a look at Plantwise in action in Zambia (YouTube):

Plantwise in Zambia

Meet Linda, a Zambian plant doctor

Meet Kenny, a Zambian farmer

 

Learn more about Plantwise at www.plantwise.org.

Round-up of Fascination of Plants Day 2016

On May 18th, botany geeks around the world shared their love of plants in this year’s Fascination of Plants Day! Here’s our round-up of some of the best #fopd tweets!

First things first, test your skills with this challenging plant science quiz:

Check out some of the amazing work done by Botanic Gardens Conservation International (BGCI):

Have you read this thought-provoking post from The Guardian?

Check out these amazing ears of maize! 

Read on to learn how signals are converted to epigenetic memory:

More from BGCI:

Includes the amazing subheading “Ovules before brovules”!:

Great to hear from some of our younger plant scientists:

Some fun facts to share with your friends:

A fantastic image featuring the adaptations of marram grass to its sand-dune home:

This fascinating mutation results from an elongated apical meristem:

How long does this starch need to last? Plants use their internal circadian clock to ration their energy stores:

The loblolly pine’s genome is over seven times larger than yours!

Need more Fascinating Plants? There are lots of great ‘Roots and Shoots’ articles on eLife‘s Medium page

How did you celebrate Fascination of Plants Day this year? Let us know in the comments below!

A year at the Global Plant Council

Last April I joined the Global Plant Council as a New Media Fellow along with Sarah Jose from the University of Bristol. The GPC is a small organization with a big remit: to bring together stakeholders in the plant and crop sciences from around the world! As New Media Fellows, Sarah and I have have assisted in raising the online profile of the GPC through various social media platforms. We wrote about our experiences in growing this blog and the GPC Twitter and Facebook accounts in the The Global Plant Council Guide to Social Media, which details our successes and difficulties in creating a more established online presence.

 

Why do it?

My wheat growing in Norfolk field trials. I have spent every summer for the past 3 years out here analysing photosynthesis and other possible contributors to crop yield

My wheat growing in Norfolk field trials. I have spent every summer for the past 3 years out here analysing photosynthesis and other possible contributors to crop yield

I chose to apply for the fellowship during the third year of my PhD. Around this time I had started to consider that perhaps a job in research wasn’t for me. It was therefore important to gain experience outside of my daily life in the lab and field, explore possible careers outside of academia and of course to add vital lines to my CV. I still loved science, and found my work interesting, so knew I wanted to stay close to the scientific community. Furthermore, I had always enjoyed being active on Twitter, and following scientific blogs, so the GPC fellowship sounded like the perfect opportunity!

 

The experience

I think I can speak for both Sarah and myself when I say that this fellowship has been one of the best things I’ve done during my PhD. Managing this blog for a year has allowed me to speak to researchers working on diverse aspects of the plant sciences from around the world. My speed and writing efficiency have improved no end, and I can now write a decent 1000 word post in under an hour! I discovered the best places to find freely available photos, and best way to present a WordPress article. Assisting with Twitter gave me an excuse to spend hours reading interesting articles on the web – basically paid procrastination – and I got to use my creativity to come up with new ways of engaging our community.

Next career move, camera woman?

Filming interviews at the Stress Resilience Forum. Next career move, camera woman?

Of course going to Brazil for the Stress Resilience Symposium, GPC AGM and IPMB was a highlight of my year. I got to present to the international community both about my own PhD research and the work of the GPC, Sarah and I became expert camera women while making the Stress Resilience videos, and I saw the backstage workings of a conference giving out Plantae badges on the ASPB stand at IPMB. It didn’t hurt that I got to see Iguassu Falls, drink more than a few caipirinhas and spend a sneaky week in Rio de Janeiro!

Helping out on the ASPB stand

Helping out on the ASPB stand with Sarah

 

Thank you

Working with the GPC team has been fantastic. I learnt a lot about how scientific societies are run and the work they do by talking to the representatives from member societies at the AGM. The executive board have been highly supportive of our activities throughout. Last but not least, the lovely GPC ladies, Ruth, Lisa and Sarah have been an amazing team to work with – I cannot thank you enough!

I have now handed in my PhD, left the GPC, and moved on to a new career outside of academic research. I’m going into a job focused on public engagement and widening access to higher education, and have no doubt my GPC experiences have helped me get there. My advice if you’re unsure about where you want to end up after your PhD? Say “yes” to all new opportunities as you never know where they will take you.

Thank you the GPC! Hopefully I’ll be back one day!

 

Thank you! It's been amazing!

Thank you! It’s been amazing!

Flowers of the Global Plant Council

A while ago we published a blog post about the sequencing of the Bauhinia genome. Bauhinia x blakeana is the national flower of Hong Kong, so naturally this sparked our interest in the global importance of flowers as national symbols, such as the English rose. Here we list just a few of the more interesting and unusual plants that are the national symbols of countries hosting GPC member organizations.

India       Indian Society for Plant Physiology

Nelumbo nucifera

The Lotus Plant

The Lotus Plant (Nelumbo nucifera) is an aquatic plant in the Nelumbonaceae family, and is the national flower of India and Vietnam. Image by alterna used under Creative Commons 2.0.

The lotus plant (Nelumbo nucifera) is considered sacred in the Buddhist and Hindu religions, and been used for over 7000 years in Asia as a source of food, herbal remedy and fibers for clothing. In 2013 its genome was sequenced, allowing its phylogenetic history and adaptations for the aquatic environment to be more fully understood.  For example, the plant has a number of genes enabling its adaptation to the nutrient poor soils in waterways, altering its novel root growth, iron regulation and phosphate starvation.

Researchers at the University of Adelaide, Australia, showed that the lotus actually has the ability to regulate the temperature of its flowers, maintaining them between 30 and 36 °C even when air temperature dropped below this. Quite how or why it does this is still unknown, but warmer flowers could play a role in attracting cold-blooded insects and increasing their activity once on the flowers to enhance pollination. An alternative explanation could be that warmer temperatures are required for pollen production.

Another fantastic fact about the lotus is seed viability. A 1300 year old lotus fruit found in a dry lakebed in China was successfully germinated, providing an insight into the aging process of fruits and other organisms

Australia      Australian Society of Plant Scientists

Acacia pycnantha

Acacia

The golden wattle (Acacia pycnantha) is a member of the Fabaceae family. The plant is a small tree that can grow up to 12 meters high! In Australia the 1st September is National Wattle Day. Image by Sydney Oats used under Creative Commons 2.0.

The Australian national flower is the Acacia pycnantha, or wattle, first described in 1942. Its name comes from the Greek pyknos (dense) and anthos (flowers) describing the dense groups of flowers that form on the tree. The wattle is an important source of tannins, and as such has been introduced to parts of southern Europe such as Italy and Portugal in addition to India and New Zealand. The wattle is also found in South Africa where it has now become an invasive pest, and various methods of biological control such as gall forming wasps (Trichilogaster signiventris) are being used to control populations.

Galls on Acacia

Galls on a wattle tree from T. signiventris. Eggs are laid by the wasp in the buds of flower heads and the hatched larvae induce gall formation which prevents flower development. This in turn prevents pollination and continued propagation of the Wattle population. Image by Sydney Oats used under Creative Commons 2.0.

Japan      The Japanese Society of Plant Physiologists

Yellow Chrysanthemum

Yellow Chrysanthemum

The yellow Chrysanthemum is a member of the Asteraceae family. Species of the Chrysanthemum enus are popular ornamental plants, and as such many hybrids and thousands of cultivars in a variety of colors and shapes can be found. Image by Joe deSousa used under Creative Commons 1.0.

Although cherry blossom is often the flower most associated with Japan, yellow Chrysanthemum flowers are equally as important. The flower is used as the Imperial Seal of Japan and on the cover of Japanese passports. Species of the genus Chrysanthemum are members of the Asteraceae (daisy) family.

Two species of the Chrysanthemum genus, C. cinerariifolium and C. coccineum, synthesize pyrethrum compounds, which attack insect nervous systems. As such these species make good companion plants in the field, repelling insects from economically valuable neighboring plants that do not have their own defense mechanisms. The naturally produced toxins are widely used in organic farming, and many synthetic versions are also available commercially.

South Africa      African Crop Science Society

Protea cynaroides

King Protea

The king protea (Protea cynaroides)  is a member of the Proteaceae family and the national flower of South Africa. The South African cricket team has the nickname the Proteas, after the flower. Image by Virginia Manso, used under Creative Commonds 2.0.

The king protea (Protea cynaroides) can grow up to 2 meters in height and comes in several colors and varieties. The plant grows in harsh, dry regions prone to wildfire, and as such has a number of adaptations for the environment. For example, a long tap-root is used for accessing deep water, and tough leathery leaves are resilient to both biotic and abiotic stress. The protea has a thick underground stem with many dormant buds. After a wildfire these dormant buds can become active, forming new stems allowing the plant to survive!

The king protea is only one species within the large Proteaceae family, 120 species of which are now endangered listed on the IUCN Red List of threatened species. The Protea Atlas Project aims to map the geographical location of proteas through Southern Africa in order to help preserve the family. In addition to protea, Southern Africa is home to around 24 000 plant taxa, 80% of which occur no where else in the world. A wider objective of the Protea Atlas Project is to map species-richness patterns in Southern Africa. The distribution of Protea plants within the region largely seems to match the species-richness patterns of other plant species, and therefore proteas are being used as surrogates for plant diversity. Find out more about the project and get involved here.

Germany and Estonia      EUCARPIA, EPSO, FESPB, SPPS

Centaurea cyanus

Cornflower

The cornflower (Centaurea cyanus) is a member of the Asteraceae family, like the Chrysanthemum. Image by Anita used under Creative Commons 2.0.

We have a large number of European and Scandinavian member groups, and choosing one flower to represent all of those was a challenge. However, the humble Cornflower seemed an appropriate choice to represent our European societies. This member of the daisy family is not only the national flower of Germany and Estonia, but has a place in many Scandinavian cultures being the symbol for a number of political parties in Finland and Sweden.

In the past this beautiful flower was regarded as a weed, but now due to intensive agricultural practices has become endangered. Cornflowers have many uses in addition to being an ornamental plant. The plant is used in many blends of herbal tea, flowers are edible in salads, and the blue coloring can be used as a clothes dye.

Canada           Canadian Society of Plant Biologists

Acer 

Although not technically a flower, the leaf of the maple tree  is such an iconic symbol on the Canadian flag we just had to include it (we are the Global Plant Council after all). There are many species of maple tree in the genus Acer, which can be distinguished from other genus of trees by their distinctive leaf shape. The most important species of maple in Canada is probably Acer saccharum, the sugar maple. The sap of this species is the major source of maple syrup, and its hard wood is popular for use in flooring and furniture.

Maple

Acer saccharum, the sugar maple, in Autumn. Image by Mark K. used under Creative Commons 2.0.

The sugar maple grows throughout the USA and Canada, favoring cooler climates and is a very shade tolerant species.  Despite this, the sugar maple is now in decline in many regions. It is highly susceptible to increased levels of air pollution and changes to salt levels. As such the species is now being replaced in many regions by the hardier Norway Maple.

Argentina                  Argentinian Society of Plant Physiology

Erythrina crista-galli 

E. crista-galli, the cockspur coral tree, is the national tree in Argentina. Also known in Argentina as the ceibo, the bright red flower of this tree is also the national flower of Argentina and Uruguay.

Cockspur

The bright red flowers of E.crista-galli are the national flowers of Argentina and Uruguay. Image by Gabriella F.Ruellan used under Creative Commons 2.0.

The small tree is a legume from the family Fabaceae. Characteristically of species from this family, the fruit of the cockspur coral tree are dry pods, and the roots have nodules containing nitrogen fixing bacteria making them important for increasing the available nitrogen in the soil. Although native to South America, the tree is also naturalized in Australia, where it is becoming an emerging environmental weed. The tree is invading waterways and wetlands displacing native species, and its spread is now being controlled in New South Wales.

If your country has a particularly interesting national flower that we have missed let us know! Perhaps we can include it in a future blog post.