PS3020 is a BEES plant biology field course based in London. Over a packed four days, students visit a range of internationally-renowned institutions as well as several research centres managed by industry.
Day 1 – Kew Gardens
by Lorna Murphy (3rd Year Applied Plant Biology)
To start the visit to Kew, Melanie-Jayne Howes spoke about the connection between plant chemicals and Alzheimer’s disease. There is currently no cure for Alzheimer’s, only medication to ease symptoms, and two of the current drugs on the market are plant derived – galantamine and rivastigmine. Galantamine is an alkaloid isolated from plants of the Amaryllidaceae family, primarily snowdrops and rivastigmine is derived from neostigmine, originally isolated from the Menispermaceae plant family, which proved to have unreasonable side effects (Raghavendra, 2002).
Both drugs act as acetylcholinesterase (AChE) inhibitors, an enzyme which breaks down the neurotransmitter acetylcholine (ACh) in the brain. The action of AChE in the brain can result in neuronal degeneration and a build up of amyloid proteins which clump and block neurons, all resulting in the symptoms consistent with Alzheimer’s disease. The inhibition of AChE by drugs such as rivastigmine help to ease these symptoms (Ren et al., 2004). A very interesting aspect was hearing about recent research, in which plants such as Aloe purpurea are emerging as potential neuroprotectants thanks to the presence of the phytochemicals aloin and vitexin (Lobine et al., 2017).
Howes also spoke about the importance of safety, efficacy and conservation with regard to medicinal plants. Samples of Ginseng were shown to highlight this point, with one being collected from markets in China and the other by a botanist in the field to show the variation in not only quality but also how different species can be grouped under one name. Howes emphasised that this is an important aspect of working with medicinal plants as improper identification or labelling of medicinal plants can result in severe side effects or even death.
Hauke Koch, a researcher at Kew, spoke about the interactions between plant chemicals and pollinators. He spoke about his own research identifying 85 species of bees in Kew Gardens (of 275 in the UK), and his work on the microbiome of bees (Koch & Schmid-Hempel, 2011; 2012). In the lecture we also heard about how the mass-deaths of bumblebees in urban environments from consuming Linden tree pollen could potentially be an indicator of bees starving due to a lack of other sources of nectar, leaving only the Linden trees as a source of food. Koch also worked on conditioning of bees, finding that theophylline and caffeine may alter bee behaviour.
The Fungarium at Kew was founded in 1879 and holds around 1.25 million specimens from the UK and around the world. It serves as an important point of research for mycologists such as Pepjin Kooij, who spoke to us about the collection. The uses of fungi in food, dyes and medicine (e.g Claviceps purperea in the treatment of migraines) were discussed while viewing the samples. Samples included those collected by Charles Darwin, and some samples collected before Linnaeus’ binomial nomenclature system had been implemented. Kooij also gave a great insight into how he carries out his own research and what it’s like to be a researcher at Kew.
At the Herbarium, Richard Allen spoke about some of the seven million plant specimens that have been collected at the Kew Herbarium since 1852, however specimens date back as far as 1696 from Samuel Brown’s India collection. The Herbarium is also home to Nathaniel Wallich’s collection of around 20,000 specimens. As in the Fungarium, a specimen collected by Charles Darwin was on display – Adiantum henslovianum from the Galapagos. The Herbarium also contains extinct plants, for example a pressed Solanum schumannium from Tanzania which was discovered in 2000, however the area where this thought to be shade tolerant aubergine was endemic to has since been cleared for agricultural use.
Other points of interest at Kew included the palm house and the Princess of Wales conservatory. The palm house is kept at levels of humidity, temperature etc. that create a rainforest type environment for various tropical plants to grow, with stairs to the higher level to get an aerial view of the whole glasshouse. The Princess of Wales conservatory allows visitors to experience ten different climate zones, including dry and wet tropics and an exhibit featuring carnivorous plants.
Overall, Kew Gardens makes for an enjoyable visit with information that is very applicable to the Applied Plant Biology course. A behind the scenes look at the work of the scientists at Kew and the ongoing projects was a great insight into botanical gardens and the work they do.