Bumbling Along

By Sarah Wiseman

My third week began as the second had finished; with more RNA extractions (a task left over from the week before). I have to take samples from 24 different plants of different varieties, at different stages of maturity and have learnt the hard way that it’s a bad idea to tackle more than 4 at once, as the pipetting takes too long and the quality of RNA extracted starts to degrade.

PCRSarahMore excitingly, though with little success, I ran my first polymerase chain reaction (PCR) of the project. This is an important technique used throughout modern biology to amplify small quantities of DNA into quantities which are large enough to run tests with. However, you can’t just shove random fragments of DNA into the machine and hope that the right bits will be copied. Instead, we need primers which specify the regions to be amplified by the enzymes. Primers are short fragments of nucleotides, about 20 bases (the general term for the 4 different letters of DNA – A,T,G and C) long and bind to specific sections of DNA which complement their sequence. Primers must be well-designed, to amplify only the DNA you are interested in; so some work better than others. Whilst they can bind to DNA that they don’t perfectly match (and still allow the enzymes to make more DNA), the worse the match is, the less likely binding is to happen. Additionally, if the sequence is too general, non-targeted sections of the genome might be amplified leading to a confusing result.

PCR also often acts as a confirmation stage where we can check that things are working as expected – this is very useful when most of the time you are working with colourless and anonymous liquids! Before we designed our own primers, we trialed a set which targeted the rice version of the CKP gene to see if they matched up with the gene in wheat. These primers were already available to us and if successful, we wouldn’t need to go through the primer design process ourselves. Unfortunately, whilst some genetic material was amplified, sequencing showed us that the rice primers had amplified other random sections of the wheat genome instead of accurately copying the CKP gene as hoped. With no chance of other primers working, we spent a long morning working out which short sequences of bases would best amplify the CKP gene in wheat and have placed an order for their creation by Invitrogen – a specialist biotech company (other primer design companies are available…).

Since the primers were due to arrive in the next week, all PCR work was put on hold and I spent more time in the PGF. I felt rather cruel sorting through the Arabidopsis with my supervisor, weeding out the smallest plants for binning – those which were clearly not going to be ready for use in the experiments a couple of weeks later. We even composed a song from the perspective of the imperiled plants [to the tune of Bring Me Sunshine]:

“Give me sunlight, and some soil,

Lots of nutrients and water.

A little time, a lot of air.

Give me sunlight, give me soil, give me love!”

… you don’t have to be mad to work here but it helps!

On a more plant friendly note, I spent a happy afternoon helping my supervisor repot her wheat plants. They needed more root space and had to be prepared for their move into the glasshouse around the corner which can better accommodate the plants as they grow taller. Sadly, we only managed to re-pot about 200 out of 1000 plants, so we still have a long way to go….

Vegan Mayonnaise: The Future of Food?

By Stephan Kamrad

Our diet, even today in the globalised age, is made up of surprisingly few plant species: Wheat, rice, potatoes and maize are the major carbohydrate sources for almost the entire planet. When it comes to livestock fodder, fruit and veg, the range is a bit broader but still limited to maybe a few hundred plant species and that although there are estimated to be over 400,000 plant species living on this planet!

So why is that? The reason for this is historical or at least traditional. Since the beginning of agricultural farming (~12,000 years ago) plants have been selected for productivity, palatability and resistance to pests, disease and environmental stresses. The plants we eat today are a reflection of our history, culture and tradition: the exploration of America marked a turning point in world history as well as European diets since it was the Spanish conquistadores who brought the potato plant back from their travels. Today in our globalised world, exotic fruits are flown around the planet so that we can enjoy kiwi, peaches, and strawberries, all year around. Still, rice and wheat remain the main food crops in Asia and Europe respectively as they have been for millennia.

Credit Jennifer Barry

Credit Jennifer Barry

But are we not missing out on the other 99.9% of plant species? Who can imagine what delicacies remain forever out in the wild because they have not been traditionally bred as crop plants or are simply unusual and scary to us? (Would you just eat a random berry you find in the wild?)

A company that has picked up on that is Hampton Creek, a food company based in San Francisco. They have developed a vegan mayonnaise substitute called Just Mayo. The key in developing this product was finding a substitute for the egg (yolk) traditionally used in mayonnaise. Just Mayo instead uses “Pea Proteins” as they declare it on their ingredients list. The company has screened, according to their press releases and adverts, many thousand plants for their properties and potential to replace eggs and continue to do so. “Pea” usually refers to the seeds of the Fabaceae family but what species and variety is actually used and how the protein is being extracted from the pea remains the companies secret. Known is that the product has only 65% of the saturated fatty acids of conventional mayonnaise and is cholesterol free.

“So what?” may you ask. After all organic food stores and supermarkets have been stocking plant-based alternatives for a long time, especially soy-based dairy substitutes and tofu. But the general conception is that vegan food is for hippies and leads to vitamin and protein deficiencies although it is in principle a lot more sustainable and more or just as healthy (with animal welfare being a whole other issue in our intensive meat industry). So in a way, Hampton Creek took and old idea and turned it into something more: looking at their ads and website, Just Mayo almost appears to be a superior lifestyle product with supreme nutritional value. In a funding campaign in February, the company raised 23 million USD, they were in Bill Gates’ The Future of Food feature and recruited Chris Jones (contestant of an American cooking reality show), Joshua Klein (CalTech graduate who previously worked on HIV treatment discovery), and Dan Zigmond (formerly Lead Data Scientist at Google Maps). Up to now, Just Mayo was mostly sold at up-town organic food stores, but their products are now available in Walmart (the world’s largest retailer) which will surely bring production volumes up and prices down.

Hampton Creek’s success has shown that there is a growing market for vegan products. Will this be the future of food? Are we learning to use the plants around us so that our diet becomes healthier and more sustainable without actually losing variety, money or taste?