Research Archives - Page 7 of 7 - The Global Plant Council

Mar 14

Lentils under the lens: Improving genetic diversity for sustainable food security

By Isabel | Blog, Research

This week’s post comes to us from Crystal Chan, project manager of the Application of Genomic Innovation in the Lentil Economy project led by Dr. Kirstin Bett at the Department of Plant Sciences, University of Saskatchewan.

Could you begin with a brief introduction to your research?

Our research focuses on the smart use of diverse genetic materials and wild relatives in the lentil (Lens culinaris) breeding program.

Canada has become the world’s largest producer and exporter of lentils in recent years. Lentils are an introduced species to the northern hemisphere and, until recently, our breeding program at the University of Saskatchewan involved just a handful of germplasms adapted to our climatic condition. With dedicated breeding efforts we have achieved noteworthy genetic gains in the past decade, but we are missing out on the vast genetic diversity available within the Lens genus. This is a major dilemma faced by all plant breeders: do we want consistency (sacrificing genetic diversity and reducing genetic gains over time) or diversity (sacrificing some important fixed traits and spending lots of time and resources in “backcrossing/rescue efforts”)?

In our current research, we use genomic tools to understand the genetic variability found in different lentil genotypes and the basis of what makes lentils grow well in different global environments (North America vs. Mediterranean countries vs. South Asian countries). We will then develop molecular breeding tools that breeders can use to improve the diversity and productivity of Canadian lentils while maintaining their adaptation to the northern temperate climate.

What first led you to this research topic?

Dr. Albert (Bert) Vandenberg, professor and lentil breeder at the University of Saskatchewan, noticed one of the wild lentil species was resistant to several diseases that devastate the cultivated lentil. After years of dedicated breeding effort, he was able to transfer the resistance traits to the cultivated lentil, but it took a lot of time and resources. We began looking into other beneficial traits and became fascinated with the domestication and adaptation aspects of lentil – after all lentil is one of the oldest cultivated crops, domesticated by man around 11,000 BC! With the rapid advance in genomic technology, we can start to better understand the biology and develop tools to harness these valuable genetic resources.

You have been involved in the development of tools that assist researchers to build databases of genomics and genetics data. Could you tell us more about projects such as Tripal?

Over the past six years, Lacey Sanderson (bioinformaticist in our group) has developed a database for our pulse research program at the University (Knowpulse, http://knowpulse.usask.ca/portal/). The database is specifically designed to present data that is relevant to breeders, as our group has a strong focus on variety development for the Canadian pulse crop industry. Knowpulse houses genotypic information from past and on-going lentil genomics projects, and includes tools for looking up genotypes as well as comparing the current genome assembly (currently v1.2) and other sequenced legume genomes. The tools are being developed in Tripal, an open-source toolkit that provides an interface between the data and a Drupal web content management system, in collaboration with colleagues at Washington State University.

At the moment we are developing new functionalities that will allow us to store and present germplasm information as well as phenotypic data. We are also working with our colleagues at Washington State University (under the “Tripal Gateway Project” funded by the National Science Foundation) to enhance interconnectivity between Knowpulse and other legume databases, such as the Legume Information Service (LIS) and Soybase, to facilitate comparative genomic studies.

How challenging are pulse genomes to assemble? How closely related are the various crops?

We had the fortune to lead the lentil genome sequencing initiative thanks to the support from producer groups and governments across the globe. The lentil genome is really challenging to assemble! We see nice synteny between lentil and the model legume, medicago, however the lentil genome is much bigger. We see a significant increase in genome size between chickpea and beans versus lentil (and pea for that matter), yet we have evidence to show that genome duplication is not the cause of the size increase. There are a lot of very long repetitive elements sprinkled around the genome, which makes its sequencing and proper assembly very challenging. Not to mention understanding the role of these long repetitive elements in biological functions…

What insights into crop domestication have you gained from these genomes?

That’s what we are working on right now under the AGILE (“Application of Genomics to Innovation in the Lentil Economy”) project. Stay tuned!

Do you work with breeders to develop new cultivars? What sorts of traits are most important?

Breeding is at the core of our work – both Kirstin and Bert are breeders (Kirstin has an active dry bean breeding program when she’s not busy with genomic research). All our research aims to feed information to the breeders so that they can make better crossing and selection decisions. Our work in herbicide tolerance has led to the development and implementation of a molecular marker to screen for herbicide resistance. With that marker we save time (skipping a crossing cycle) and forego the herbicide spraying test for all of our early materials.

Disease resistance and drought tolerance are also important for the growers. Visual quality (seed shape, size, color) are very important too as our customers are very picky as to what sort of lentils they like to buy/eat.

What does the future of legume/lentil agriculture hold?

Lentils have been a staple food in many countries for centuries and have been gaining popularity in North America in recent years as people are looking for plant-based protein sources. Lentils are high in fibre, protein, and complex carbohydrates, while low in fat and calories, and have a low glycemic index. They are suitable for vegetarian/vegan, gluten-free, diabetic, and heart-smart diets. Lentils also provide essential micronutrients such as iron, zinc and folates. Lentils are widely recognized as nutrient-dense food that could serve as part of the solution to combat global food and nutritional insecurity.

In modern agriculture, adding lentil or other leguminous crops in the crop rotation helps improve soil structure, soil quality, and biotic diversity, as well as enhancing soil fertility through their ability to fix nitrogen. Because pulse crops require little to no nitrogen fertilizer, they use half of the non-renewable energy inputs of other crops, reducing greenhouse gas emissions.

2016 was marked by the United Nations as the International Year of Pulses, which was great as many people have become more aware of the benefits of pulse crops on the plate and in the field.

All images are credited to Mr Derek Wright.

Feb 09

Mother grain genome: insights into quinoa

By Isabel | Blog, KAUST, Research

Sales of quinoa (Chenopodium quinoa) have exploded in the last decade, with prices more than tripling between 2008 and 2014. The popularity of this pseudocereal comes from its highly nutritious seeds, which resemble grains and contain a good balance of protein, vitamins, and minerals. The nourishing nature of quinoa meant it was prized by the Incas, who called it the “Mother grain”.

Quinoa is a popular ‘grain’, but it is more closely related to spinach and beetroot than cereals like wheat or barley. Image credit: Flickr user. Used under license: CC BY 2.0.

Quinoa is native to the Andes of South America, where it thrives in a range of conditions from coastal regions to alpine regions of up to 4000 m above sea level. Its resilience and nutritious seeds means that quinoa has been identified as a key crop for enhancing food security, but there are currently very few breeding programs targeting this species.

The challenge of improving the efficiency and sustainability of quinoa production has so far been restricted by the lack of a reference genome. This week, a team of researchers led by Professor Mark Tester (King Abdullah University of Science & Technology; KAUST) addressed this issue, publishing a high-quality genome sequence for quinoa in Nature. They compared the genome with that of related species to characterize the evolution and domestication of the crop, and investigated the genetic diversity of economically important traits.

The evolution of quinoa

Tester and colleagues used an array of genomics techniques to assemble 1.39 Gb of the estimated 1.45-1.50 Gb full length of quinoa’s genome. Quinoa is a tetraploid, meaning it has four copies of each chromosome. The researchers shed light on the evolutionary history of this crop by sequencing descendants of the two diploid species (each containing two sets of chromosomes) that hybridized to generate quinoa; kañiwa (Chenopodium pallidicaule) and Swedish goosefoot (Chenopodium suecicum). Comparing these sequences to quinoa and other relatives, the team showed that the hybridization event likely occurred between 3.3 and 6.3 million years ago. A comparison with other closely related Chenopodium species also suggested that, contrary to previous predictions, quinoa may have been domesticated twice, both in highland and coastal environments.

Quinoa field. Image credit: LID. Used under license: CC BY-SA 2.0.

Washing away quinoa’s bitter taste

Quinoa seeds are coated with soap-like chemicals called saponins, which have a bitter taste that deters herbivores. Saponins can disrupt the cell membranes of red blood cells, so they have to be removed before human consumption, but this process is costly, so quinoa breeders are always looking for varieties that produce lower levels of saponins.

Sweet (low-saponin) quinoa strains do occur naturally, but the genes that regulate this phenotype were previously unknown. Tester and colleagues investigated sweet and bitter quinoa strains and discovered that a single gene (TRITERPENE SAPONIN BIOSYNTHESIS ACTIVATING REGULATOR-LIKE 1 [TSARL1]) controls the amount of saponins produced in the seeds. The low-saponin quinoa strains contained mutations in TSARL1 that prevented it from functioning properly. This is a key target for the improvement of quinoa in the future, although farmers will have to find new ways to protect their crops from birds and other seed predators!

Quinoa flowers. Image credit: Alan Cann. Used under license: CC BY-SA 2.0.

Quality quinoa

The high-quality reference genome for quinoa generated by Tester and colleagues is likely to be vital for allowing many exciting improvements in the future. Breeders hoping to improve the yield, ease of harvest, stress tolerance, and saponin content of quinoa can develop genetic markers to speed up breeding for these key traits, improving the productivity of quinoa varieties and enhancing future food security.

Read the paper in Nature: Jarvis et al., 2017. The genome of Chenopodium quinoa. Nature. DOI: 10.1038/nature21370

Thank you to Professor Mark Tester (KAUST) for providing information used in this post!

Feb 01

The future of phenotyping

By Isabel | Blog, Future Directions, Research

This week’s post was written by Dr Kasra Sabermanesh, Rothamsted Research.

I am a post-doctoral research scientist within Rothamsted Research’s BBSRC-funded 20:20 Wheat® program, which aims to provide the knowledge base and tools to increase the UK wheat yield potential from 8.4 to 20 tons of wheat per hectare within the next 20 years. Field phenotyping is one component of this program and facilitates the non-destructive monitoring of field-grown crops. Traditional methods of field phenotyping require huge human effort, which consequently limits the accuracy, frequency, and number of different measurements that can be taken at one time. Fortunately, Rothamsted has an exciting solution to this problem.

The Field Scanalyzer

Dr Kasra Sabermanesh shows off the Field Scanalyzer. Image credit: Rothamsted Research

Our field phenotyping platform, the Field Scanalyzer (constructed by LemnaTec GmbH and being further developed by ourselves), supports a motorized measuring platform with multiple sensors that can be accurately positioned anywhere within a dedicated field. The sensor array comprises a high-definition RGB camera, two hyperspectral cameras, a thermal infrared camera, a system for imaging chlorophyll fluorescence and twin scanning lasers for 3D information capture. Together, these sensors generate a wealth of data about crop growth, architecture, performance, and health. The Field Scanalyzer operates autonomously and in high-throughput, meaning it can take a lot of non-destructive measurements without human supervision, throughout the crops lifecycle, with high-accuracy and reproducibility. (You can read more about the Field Scanalyzer in our recent paper: http://www.publish.csiro.au/FP/pdf/FP16163).

We are currently using the Field Scanalyzer to identify new characteristics of crops that relate to performance, as well as identifying new genetic diversity for existing traits. Outputs from either of these research components can be delivered to breeders. We are screening approximately 400 wheat varieties, but also imaging some oilseed rape and oat plants.

The scanalyzer. Image credit: Rothamsted Research

The big data problem

The Field Scanalyzer at Rothamsted is a world first, so we initially had to develop all the necessary image acquisition protocols and image processing tools, in order to exploit its full capabilities. A number of image processing tools are available; however, they are not suitable for field-grown crops, as they were not developed for complex canopies consisting of hundreds of plants in highly dynamic ambient conditions. The platform can generate up to 100 TB data with a year’s continuous operation (using all of the sensors). That’s why I work with two other post-docs to develop robust computer vision tools to automate the way we extracting quantitative image datasets. We are also validating the accuracy of the values extracted from our images by comparing them with measurements obtained manually.

Approximately 1.5 years have passed since we first began operating the Field Scanalyzer, and we have now optimized all of our image acquisition protocols and have collected a full seasonal dataset. With the good quality images stored in our database, we have developed some robust tools to automatically extract the information about some key growth stages (ear emergence and flowering), as well as quantifying height and the number of some plant organs. We are still just scraping the surface though, and have a list of traits for which we want to develop computer vision tools, in order to automatically analyze them.

Take to the skies: Drones for data collection

Some of my colleagues work with drones (UAVs) to capture information about crop height, plant density (Normalized Difference Vegetation Index), and canopy temperature from large-scale field trials containing 5000 plots. They also fly the UAVs over our Field Scanalyzer site, so we can compare data collected from the higher flying UAV with those collected from the Field Scanalyzer at close proximity. The way we see it, UAVs can image large fields in a very short time (15 min), so if we notice something interesting using the UAV at the large plot-scale, we can put the material under the Field Scanalyzer for high-resolution phenotyping. On the other hand, with the Field Scanalyzer, once we gain a better understanding of which trait/s we need to focus on, when we should be looking at them, and exactly which sensor/s are required to quantify the trait, we can deploy drones with the necessary sensors (once the sensors are portable enough) to collect this information at field-scale and at the appropriate time.

Taking to the skies: Drones are used for large-scale phenotyping at Rothamsted. Credit: Rothamsted Research.

The future of phenotyping

I envision that the future of phenotyping technology will focus on reducing the cost and size of cameras/sensors, ultimately increasing their portability and accessibility. This will result in more sophisticated cameras being attached to UAVs (as many of sensors we currently use far out-weigh a UAV’s payload). Parallel to this, research efforts are focusing on developing image processing systems that efficiently extract quantitative information about the crops from acquired images. Together, phenotyping systems such as low-flying UAVs that generate easily interpreted data outputs could be developed, which may be more widely adopted by breeders and farmers to get a deeper insight into their crop’s health and performance.

Jan 05

2016 Plant Science Round Up

By Isabel | Blog, Research

Another fantastic year of discovery is over – read on for our 2016 plant science top picks!

January

A Zostera marina meadow in the Archipelago Sea, southwest Finland. Image credit: Christoffer Boström (Olsen et al., 2016. Nature).

The year began with the publication of the fascinating eelgrass (Zostera marina) genome by an international team of researchers. This marine monocot descended from land-dwelling ancestors, but went through a dramatic adaptation to life in the ocean, in what the lead author Professor Jeanine Olsen described as, “arguably the most extreme adaptation a terrestrial… species can undergo”.

One of the most interesting revelations was that eelgrass cannot make stomatal pores because it has completely lost the genes responsible for regulating their development. It also ditched genes involved in perceiving UV light, which does not penetrate well through its deep water habitat.

Read the paper in Nature: The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea.

BLOG: You can find out more about the secrets of seagrass in our blog post.

February

Plants are known to form new organs throughout their lifecycle, but it was not previously clear how they organized their cell development to form the right shapes. In February, researchers in Germany used an exciting new type of high-resolution fluorescence microscope to observe every individual cell in a developing lateral root, following the complex arrangement of their cell division over time.

Using this new four-dimensional cell lineage map of lateral root development in combination with computer modelling, the team revealed that, while the contribution of each cell is not pre-determined, the cells self-organize to regulate the overall development of the root in a predictable manner.

Watch the mesmerizing cell division in lateral root development in the video below, which accompanied the paper:

Read the paper in Current Biology: Rules and self-organizing properties of post-embryonic plant organ cell division patterns.

March

In March, a Spanish team of researchers revealed how the anti-wilting molecular machinery involved in preserving cell turgor assembles in response to drought. They found that a family of small proteins, the CARs, act in clusters to guide proteins to the cell membrane, in what author Dr. Pedro Luis Rodriguez described as “a kind of landing strip, acting as molecular antennas that call out to other proteins as and when necessary to orchestrate the required cellular response”.

Read the paper in PNAS: Calcium-dependent oligomerization of CAR proteins at cell membrane modulates ABA signaling.

*If you’d like to read more about stress resilience in plants, check out the meeting report from the Stress Resilience Forum run by the GPC in coalition with the Society for Experimental Biology.*

April

This plant root is infected with arbuscular mycorrhizal fungi. Image credit: University of Zurich.

In April, we received an amazing insight into the ‘decision-making ability’ of plants when a Swiss team discovered that plants can punish mutualist fungi that try to cheat them. In a clever experiment, the researchers provided a plant with two mutualistic partners; a ‘generous’ fungus that provides the plant with a lot of phosphates in return for carbohydrates, and a ‘meaner’ fungus that attempts to reduce the amount of phosphate it ‘pays’. They revealed that the plants can starve the meaner fungus, providing fewer carbohydrates until it pays its phosphate bill.

Author Professor Andres Wiemsken explains: “The plant exploits the competitive situation of the two fungi in a targeted manner, triggering what is essentially a market-based process determined by cost and performance”.

Read the paper in Ecology Letters: Options of partners improve carbon for phosphorus trade in the arbuscular mycorrhizal mutualism.

May

The transition of ancient plants from water onto land was one of the most important events in our planet’s evolution, but required a massive change in plant biology. Suddenly plants risked drying out, so had to develop new ways to survive drought.

In May, an international team discovered a key gene in moss (Physcomitrella patens) that allows it to tolerate dehydration. This gene, ANR, was an ancient adaptation of an algal gene that allowed the early plants to respond to the drought-signaling hormone ABA. Its evolution is still a mystery, though, as author Dr. Sean Stevenson explains: “What’s interesting is that aquatic algae can’t respond to ABA: the next challenge is to discover how this hormone signaling process arose.”

Read the paper in The Plant Cell: Genetic analysis of Physcomitrella patens identifies ABSCISIC ACID NON-RESPONSIVE, a regulator of ABA responses unique to basal land plants and required for desiccation tolerance.

June

Professor Michael Knoblauch shows off a microscope image of phloem tubes. Image credit: Washington State University.

Sometimes revisiting old ideas can pay off, as a US team revealed in June. In 1930, Ernst Münch hypothesized that transport through the phloem sieve tubes in the plant vascular tissue is driven by pressure gradients, but no-one really knew how this would account for the massive pressure required to move nutrients through something as large as a tree.

Professor Michael Knoblauch and colleagues spent decades devising new methods to investigate pressures and flow within phloem without disrupting the system. He eventually developed a suite of techniques, including a picogauge with the help of his son, Jan, to measure tiny pressure differences in the plants. They found that plants can alter the shape of their phloem vessels to change the pressure within them, allowing them to transport sugars over varying distances, which provided strong support for Münch flow.

Read the paper in eLife: Testing the Münch hypothesis of long distance phloem transport in plants.

BLOG: We featured similar work (including an amazing video of the wound response in sieve tubes) by Knoblauch’s collaborator, Dr. Winfried Peters, on the blog – read it here!

July

Preserved remains of rope, seeds, reeds and pellets (left), and a desiccated barley grain (right) found at Yoram Cave in the Judean Desert. Credit: Uri Davidovich and Ehud Weiss.

In July, an international and highly multidisciplinary team published the genome of 6,000-year-old barley grains excavated from a cave in Israel, the oldest plant genome reconstructed to date. The grains were visually and genetically very similar to modern barley, showing that this crop was domesticated very early on in our agricultural history. With more analysis ongoing, author Dr. Verena Schünemann predicts that “DNA-analysis of archaeological remains of prehistoric plants will provide us with novel insights into the origin, domestication and spread of crop plants”.

Read the paper in Nature Genetics: Genomic analysis of 6,000-year-old cultivated grain illuminates the domestication history of barley.

BLOG: We interviewed Dr. Nils Stein about this fascinating work on the blog – click here to read more!

August

Another exciting cereal paper was published in August, when an Australian team revealed that C₄ photosynthesis occurs in wheat seeds. Like many important crops, wheat leaves perform C₃ photosynthesis, which is a less efficient process, so many researchers are attempting to engineer the complex C₄ photosynthesis pathway into C₃ crops.

This discovery was completely unexpected, as throughout its evolution wheat has been a C3 plant. Author Professor Robert Henry suggested: “One theory is that as [atmospheric] carbon dioxide began to decline, [wheat’s] seeds evolved a C₄ pathway to capture more sunlight to convert to energy.”

Read the paper in Scientific Reports: New evidence for grain specific C4 photosynthesis in wheat.

September

Professor Stefan Jansson cooks up “Tagliatelle with CRISPRy fried vegetables”. Image credit: Stefan Jansson.

September marked an historic event. Professor Stefan Jansson cooked up the world’s first CRISPR meal, tagliatelle with CRISPRy fried vegetables (genome-edited cabbage). Jansson has paved the way for CRISPR in Europe; while the EU is yet to make a decision about how CRISPR-edited plants will be regulated, Jansson successfully convinced the Swedish Board of Agriculture to rule that plants edited in a manner that could have been achieved by traditional breeding (i.e. the deletion or minor mutation of a gene, but not the insertion of a gene from another species) cannot be treated as a GMO.

Read more in the Umeå University press release: Umeå researcher served a world first (?) CRISPR meal.

BLOG: We interviewed Professor Stefan Jansson about his prominent role in the CRISPR/GM debate earlier in 2016 – check out his post here.

*You may also be interested in the upcoming meeting, ‘New Breeding Technologies in the Plant Sciences’, which will be held at the University of Gothenburg, Sweden, on 7-8 July 2017. The workshop has been organized by Professor Jansson, along with the GPC’s Executive Director Ruth Bastow and Professor Barry Pogson (Australian National University/GPC Chair). For more info, click here.*

October

Phytochromes help plants detect day length by sensing differences in red and far-red light, but a UK-Germany research collaboration revealed that these receptors switch roles at night to become thermometers, helping plants to respond to seasonal changes in temperature.

Dr Philip Wigge explains: “Just as mercury rises in a thermometer, the rate at which phytochromes revert to their inactive state during the night is a direct measure of temperature. The lower the temperature, the slower phytochromes revert to inactivity, so the molecules spend more time in their active, growth-suppressing state. This is why plants are slower to grow in winter”.

Read the paper in Science: Phytochromes function as thermosensors in Arabidopsis.

November

A fossil ginkgo (Ginkgo biloba) leaf with its modern counterpart. Image credit: Gigascience.

In November, a Chinese team published the genome of Ginkgo biloba¸ the oldest extant tree species. Its large (10.6 Gb) genome has previously impeded our understanding of this living fossil, but researchers will now be able to investigate its ~42,000 genes to understand its interesting characteristics, such as resistance to stress and dioecious reproduction, and how it remained almost unchanged in the 270 million years it has existed.

Author Professor Yunpeng Zhao said, “Such a genome fills a major phylogenetic gap of land plants, and provides key genetic resources to address evolutionary questions [such as the] phylogenetic relationships of gymnosperm lineages, [and the] evolution of genome and genes in land plants”.

Read the paper in GigaScience: Draft genome of the living fossil Ginkgo biloba.

December

The year ended with another fascinating discovery from a Danish team, who used fluorescent tags and microscopy to confirm the existence of metabolons, clusters of metabolic enzymes that have never been detected in cells before. These metabolons can assemble rapidly in response to a stimulus, working as a metabolic production line to efficiently produce the required compounds. Scientists have been looking for metabolons for 40 years, and this discovery could be crucial for improving our ability to harness the production power of plants.

Read the paper in Science: Characterization of a dynamic metabolon producing the defense compound dhurrin in sorghum.

Another amazing year of science! We’re looking forward to seeing what 2017 will bring!

P.S. Check out 2015 Plant Science Round Up to see last year’s top picks!

Jan 01