Sarah Jose



Cardiff University (2007 – 2011), University of Bristol (2012 – present and beyond!)


BSc in Biology

Work History:

I worked for a year at the Royal Botanic Gardens, Kew, where I did a lot of DNA sequencing!

What I do now:

I am a PhD student at the University of Bristol as well as a blogger about all things environment on the University’s blog.

My Interview

I’m a…


What I do

I am a PhD student at the University of Bristol, looking at the shiny waxy surfaces on the leaves of plants and the tiny pores (known as stomata) that they use to breathe. Hopefully I will find out more about how plants use and store water and how they avoid drying out in sunny weather. One day we might use this knowledge to be able to grow crops in countries with bad droughts.

The biggest food challenge facing society today..

How can we feed an extra three billion people in the year 2050 when there is no more land available for farming?

How would you describe yourself in 3 words?

Enthusiastic, happy, Cornish.

Who is your favourite singer or band?

The Beatles!

What's your favourite food?

Pizza or Mexican food. Maybe Mexican pizza??

What is the most fun thing you've done?

University trip to Kenya – safaris, coral reef snorkelling and giant biting ants!

If you had 3 wishes for yourself what would they be? - be honest!

1. I’d love some land to grow food and keep chickens. 2. Stay happy. 3. £1,000,000!

Tell us a joke.

What do you call a donkey with three legs? A wonkey!

Other stuff

Work photos:

I mainly work with barley, which is a crop plant a bit like wheat. I usually grow it in special growth chambers, which regulate the temperature, light and humidity (moisture in the air) that the plants receive.


Beautiful barley!

The first part of my PhD was to look at microscopic pores on the leaf surfaces, known as “stomata”. Stomata let carbon dioxide into the leaf for photosynthesis but can also be closed to stop too much water from evaporating.


Here are some open and nearly closed barley stomata

If your school has a microscope, you could look at stomata too! Just get some clear nail varnish and paint it onto a leaf. When it has dried, stick a piece of clear sticky tape onto the nail varnish and pull it off again. The nail varnish should stick to the tape. Finally, stick the tape onto a microscope slide and look at it under the microscope! Use a higher magnification to see them better.


Nail varnish impression of a leaf

Plants cannot move, so have to deal with whatever conditions their environment throws at them. They can open and close their stomata in response to lots of things, including light, water and temperature.

I can test how well the stomata open and close by using a thin peel from a leaf and incubating it in different conditions. After a few hours, I can measure how open they are under a microscope.


Really thin transparent strips of leaves floating in small Petri dishes

A really cool piece of equipment we use is a thermal imaging camera. It uses infra-red to test how hot plants are compared to their surroundings. Unlike animals, plants are usually a few degrees colder than their surroundings because water evaporates from their surfaces, often through their stomata. It’s a bit like sweating; the water takes away the heat with it.


Thermal image of barley – the plants are cooler than the room