Five Plants of Christmas

Merry Christmas everyone!

In celebration of the upcoming Christmas celebrations here is a more Christmassy themed post- a few facts about our favourite christmas plants.

1.) Mistletoe.

“Christmas time, Mistletoe and wine…”

Mistletoe is a plant which has been written about in stories, poems and songs for hundreds of years, and now is synonymous with Christmas. It is a semi-parasitic plant-taking essential nutrients from its host plant, but is also able to make some things itself. Mistletoe grows in the canopies of trees, and can grow into huge balls up to 1m wide. Although Mistletoe may look pretty- its poisonous, so don’t go eating any of its beautiful white berries!


Mistletoe leaves are green all year round- the greenery of mistletoe in the depths of winter and abundance of its berries shows its vitality in an otherwise dormant season- and may be why it has been such a popular decoration in homes since the 16th century.

As for the kissing under the mistletoe? Its a tradition that has been around since the 1700s… though the reason behind it is unknown!

2) Holly

“The Holly bears a berry…”

Holly is an evergreen shrub with glossy spiky dark green leaves, and bright red berries. These berries are a important source of food for many birds and animals- though I wouldn’t recommend you eat them unless you want to be extremely ill for Christmas, as like mistletoe holly berries are toxic.


Interestingly- Holly trees don’t contain both male and female organs, instead being either Male or Female, with only the female trees produce the red berries. So, the holly we often see in decorations for Christmas are from female Holly trees.

As another plant which stays vibrant green, and produces beautiful berries- Holly represents fertility, and was thought to protect homes in which it was hung.

Holly is associated with males- bringing good luck and protection, with Ivy being the female counterpart. This is why so many Christmas carols refers to both the Holly and the Ivy.

3.) Ivy

“The Holly and the Ivy…”

Ivy is commonly seen growing up through trees, or on the side of buildings, and is one of the UK’s few native evergreen plants. As with Holly, Ivy is extremely important for wildlife, providing much needed shelter and food- although once again Ivy is poisonous to us. Poison Ivy often talked about in America, is completely unrelated to Ivy.

Ivy has got a bad rep over the years- said to suffocate plants, and be very damaging- though this is not true! Although Ivy does use trees for climbing, it isn’t parasitic and so doesn’t directly harm trees.


As a evergreen plant, like Holly and Mistletoe, it was seen as a important symbol in winter keeping evil sprits away. A wreath of Ivy around the head was even thought to prevent you from getting drunk- which could be worth trying out at the office Christmas party!

4.) Chestnuts

“Chestnuts roasting on an open fire…”

The chestnut is a group of 8-9 species of deciduous trees and shrubs in the family Fagaceae, and also refers to the edible nuts produced. Chestnuts are not the same as Horse chestnuts (the nuts are mildly poisonous), or water chestnuts!


Chestnuts are very different from other nuts as they are low in fat, high in fibre, and high in a whole load of minerals and vitamins- making them the perfect Christmas feast! They are also the only nut to contain vitamin C.

5.) Poinsettias

The flower of winter. Poinsettias are shrubs or small trees, which have dark green leaves, and coloured bracts (specialised leaves)- we mostly see poinsettias with Red bracts, but these can also be orange, pale green and pink. Although these bracts give the appearance of petals, they are actually leaves!


Poinsettias are one of the most popular plants for Christmas floral arrangements- with their bright green and red leaves, but they aren’t the ‘obvious’ Christmas plant choice, being a plant native to Mexico. The Poinsettia is a fairly recent addition to Christmas- it was only introduced to America in 1828. Although it took a while to catch on, Poinsettias are now found in Christmas floral arrangements everywhere.

Why are Poinsettas linked to Christmas? There are a few theories, one is that the plant is a symbol of the star of Bethlehem.

I wish you all a very Merry Christmas, I will be having a break and returning after the New Year with more blog posts for you 🙂


All photos from Pixabay.


What is Plant transformation? Part 2: Transient transformation

A few weeks ago I wrote a post about stable plant transformation, which is used for the long-term research of genes, and for long-term production of a trait/compound. This post is going to focus on another plant transformation technique: Transient transformation.

What is transient transformation?

Transient transformation is a mechanism to introduce or silence genes temporarily in plants in order to make specific proteins. This method is very versatile, efficient and quick to do compared to traditional stable plant transformation.

How do you do transient transformation?

Like with stable transformation, the naturally occuring soil bacteria: Agrobacterium tumefaciens is used.  A gene of interest is introduced into agrobacterium as outlined here. The agrobacterium containing the desired gene is then grown in liquid culture until a high density of bacteria is reached. This suspension of agrobacterium is then either directly introduced into plant leaves via injection, or into whole plants via vacuum infiltration.


One of the most widely used methods of agrobacterium infiltration is direct injection into plant leaves. For this the agrobacterium solution is put into a syringe with no needle. The tip of the syringe is placed against the leaf, and using a slight pressure, injected into the leaf.  The suspension is taken up into the air spaces of the leaf.

Through this method, several different strains of agrobacterium can be injected into different areas of plant leaves at the same time- allowing multiple comparisons of different gene combinations to be studied at the same time.


source: Wikimedia. Infiltration of agrobacterium into Nicotiana benthamiana leaves


Click here for a video of agro-infiltration into a tobacco leaf.

Vacuum infiltration

This allows deep penetration of the agrobacterium into plant tissues, and can be used to infiltrate entire plants. Normally young plants will be infiltrated by this mechanism. What is particularly good about this mechanism is that a plantlet infiltrated with agrobacterium will continue to grow and show any altered physiological changes, however will not pass any of these changes to its offspring- the change to gene expression is temporary.

For vacuum infiltration the plant is submerged into a solution of agrobacterium, before a vacuum is applied. Under vacuum conditions air is forced out of the intracellular air spaces in the leaves of the plant via the stomata. When the vacuum is then reversed, the change in pressure means the agrobacterium solution is taken up via the stomata into the plant tissue.

Why we use Transient expression systems:

  • Transient expression is a much faster method than stable transformation
  • Products of gene activity such as recombinant proteins, are made days after initial agrobacterium infiltration.
  • It can easily be scaled up for commercial uses
  • Co-infiltration of agrobacterium with different genes can be used to produce recombinant proteins
  • Can be used for the targeted silencing of genes (supression of gene activity)
Leaf which has been infiltrated with agrobacterium after 3 days. Lighter colouring in leaf shows where the agrobacterium has infiltrated the leaf tissue. Fluorescent tags such as Green Fluorescent protein can be used to track protein expression and show activity.


Example: commercial use- Vaccine production

Recent work by the George Lomonosoff Lab in the John Innes centre has shown that the transient expression system can be used to produce high yields of a polio vaccine in a short amount of time.

The plant Nicotiana benthamiana is a member of the tobacco species- and is ideally suited for use with the transient expression system for commercial production of antibodies and vaccines: as it is extremely quick to grow, and can be used for agrobacterium infiltration after just one week.

Using the transient expression system, virus-like particles (VLPs)- particles designed to look exactly like the polio virus, without the virus-causing element, were produced in the leaves of N. benthamiana. The Virus like particles were extracted from the leaves, and used to make a vaccine which was shown to successfully prevent polio virus in animal studies.

The great thing about this system, is that a large number of plants can be infiltrated with agrobacterium at once, and will actively begin producing its product after just a few days. It is thought that this technology may be able to be used for the production of a wide variety of vaccines, and due to the rapid and cost-effective mechanism, you could potentially go from having no vaccine to a vaccine just 4 weeks after identification of a viral strain.  This would be a massive improvement on the timescale of current vaccines- for example a vaccine for flu currently takes a few months to generate. This technology still needs some development, but watch this space!


For more information about Transient expression: (It was very hard to find articles in the public domain which show more about transient transformation- if you know of any, please leave a comment and I will add them to the list below)

In depth science research paper: (you may need specific access for this) (again access may be required)

More about the use of plants for production of polio vaccine:

Feauture image source: wikimedia


The Model plant

Hello, and welcome to the first of my new blog series, which is going to be all about plant science. In this series I want to write about plant science- what plant scientists do, the basics of some of the experiments we carry out, and interesting things about plant science.

In this post I will be introducing you to Arabidopsis, one of the most widely studied plants.

Continue reading “The Model plant”

Does plant science have a image problem?

Where are all the plant scientists?

This week I went on a mission- to find more plant science blogs to follow. Although science publications are great for communicating science to each other, it is nice to read about what others are doing in a less academic setting- via blogs.

Continue reading “Does plant science have a image problem?”