by Nathan Smith
It’s Christmas day. Presents? Check. Phoned relatives? Check. Watch It’s a Wonderful Life? Check. The only thing left is the Christmas dinner; the turkey, the parsnips, the potatoes…and the Brussels sprouts. You’re not a fan but you’ve always eaten them out of politeness, concealing your looks of disgust behind a glass of wine, but not this year. Starting a New Year’s Resolution early, you’ve sworn that no more Brussels sprouts will touch your lips. But how do you get out of this time-hallowed culinary tradition? The answer: Science.
Credit: Eric Hunt
For you see, Brussel Sprouts contain large amounts of a chemical similar to PTC (phenylthiocarbamide) and we humans have receptors in our taste buds that detect PTC. It’s encoded by the TAS2R38 gene and translates the presence of PTC into a bitter taste sensation. The best news for sprout haters? It is predicted that up to 70% of the population carries this gene. Now providing no-one in your family has a DNA-testing kit, this alone should guarantee you a sprout-free Christmas. Huzzah!
by Lilian Halstead
Most people know that when you meet someone under the mistletoe at Christmas time you have to give them a kiss, but like many evergreen plants it had a role in winter solstice customs before being incorporated into Christmas celebrations. In fact, it is often banned from Church decorations due to being considered a pagan plant, probably because it is believed to have been highly valued by the druids.
In Norse mythology the god Baldr was killed using a weapon made of mistletoe, it being the only thing his mother couldn’t get to swear never to harm him. In Greek myth Aeneas has to pick the golden bough in order to visit the underworld, it is speculated that the golden bough is mistletoe due to the fact it appears golden in winter.
However, the main role of mistletoe in British folklore is as a fertility symbol. In addition to being used as something to kiss under, mistletoe has been used also as a treatment for infertility and as a charm for women to help them find husbands.
And if that is not enough, it has also been used as a symbol of peace and good luck.
by Sophie Harrington
It’s that time of year again, when those shiny green leaves and red berries start appearing all around. Holly is a fixture of Christmas time, but despite being so familiar, it can still manage to surprise.
Credit: Liz West
Holly is a completely dioecious species, which means that holly plants are either male or female. This is very different to most plants, which either have bisexual flowers or a combination of male and female flowers on the same plant. This state of affairs may be the most common to us animals, but considering plants are immobile, this could be very inconvenient indeed! After all, how are the male plants supposed to reach the female plants?
Luckily for holly, and our Christmas wreaths, honeybees are particularly good pollinators. As long as there is one male plant in the vicinity, up to 20 female plants can be pollinated from that single plant. Pretty impressive! Never let it be said that bees don’t work for their keep—they might be the ultimate wingmen.
By Charlie Whittaker
We all get a bit chilly around Christmas, but unfortunately the plants amongst us don’t have the luxury of being able to up-root, put on a jumper and snuggle up by the fireside. So are plants condemned to wither and perish, rooted in the cold, freezing their (metaphorical) socks off under a covering of snow?
The answer is unequivocally no. Some plants are able to engage in a process called thermogenesis, by which a vast amount of heat gets produced through metabolic processes such as respiration. Using an alternative pathway, the majority of the energy released by respiration gets emitted as heat, as opposed to being converted to chemical energy.
Being warm has its benefits. In areas that see snowfall during the winter, the process of thermogenesis (which can raise the plant’s temperature by up to 30C!) helps to melt the snow covering the plant. This allows the plant to start photosynthesizing earlier than its competitors and, in the case of seedlings, germinate and sprout earlier than other plants — giving them a competitive advantage!
By Joanna Wolstenholme
Mistletoe is everywhere is Cambridge – look up into the trees and you will often spot dense balls of twigs sprouting from a branch. But other than its mystical and romantic connotations, does mistletoe actually have any clinically proven medical use?
Rudolf Steiner is credited with being the first to raise a link between mistletoe and cancer, admittedly on a rather dubious basis. His school of thought, anthroposophy, followed the maxim, ‘like cures like’. Mistletoe, like cancer, is a parasite, and so it of course follows that mistletoe will be able to cure cancer.
However, clinical trials prompted by many people following Steiners advice, have had mixed outcomes. In several trials, cancer patients treated with various forms of mistletoe preparations have had fewer side effects, better symptom relief and survived longer after beating the cancer. However many of these trials were flawed as they had major weaknesses, such as studying just a few patients and lack of information about mistletoe dose. There are also some side effects (but then what cancer therapy doesn’t have side effects?) such as inflammation at the injection site, headache and fever.
Yet one compound found in mistletoe that may not be so welcome is its lectin, which is similar in structure to the castor bean lectin, the infamous ricin (that of the end of the umbrella to kill a journalist fame). As with many medicines that come with plants, the answer will be to identify the useful active agent produced by mistletoe and find a way to either purify it or synthesise it artificially. Until that point, however, it serves as a reminder of how powerful plant chemicals can be – for good and harm!
By Toby McMaster
The living room’s most popular festive feature, the Fraser fir, has no immunity against the phytophthora root pathogen, infamous amongst plant pathologists, with its greek name meaning ‘plant destroyer’. Professor John Frampton of North Carolina State University is out to change that.
Credit: Teresa Sikora
A species of phytophthora caused the potato blight of the great Irish famine and no variant of the Fraser fir has ever been found to be even slightly resistant to the disease. However help is at hand from the Fraser’s Japanese cousin, the Momfi fir, which makes an awful Christmas tree itself but is incredibly resistant to phytophthora.
Fraser firs can be grafted onto the roots of a Momfi, to produce a chimera with the best of both worlds: resistant roots and the beautiful Christmassy look of a Fraser. Frampton’s lab is attempting to find genetic sequences encoding root-rot resistance but this is a slow process, genetic modification of Christmas trees is likely to be a thing of the distant future. Even when good trees are found and researchers cross them it takes firs 10 to 12 years before they can reproduce and after this another 6 or so to judge the quality of the resulting progeny.
However eventually researchers hope to get to the root of the problem.