Hello and welcome to my blog! My name is Caroline and I am a PhD student at the University of Sheffield. My research project focuses on Striga - a genus of parasitic plants that devastates harvests by infecting food crops. I am exploring the defence reactions that can make host plants more resistant against Striga. Due to my ongoing battles with anorexia, I haven't made as much progress as I would have liked but I am determined to finish the course.


This blog charts the ups and downs of life in the lab, plus my dreams to become a science communicator and forays into public engagement and science policy....all while trying to keep my mental and physical health intact. Along the way, I'll also be sharing new plant science stories, and profiles of some of the researchers who inspire me on this journey. So whether you have a fascination for plants, are curious about what science research involves, or just wonder what exactly I do all day, read on - I hope you find it entertaining!


Monday, 14 October 2013

'A PhD should be regarded as a form of training...'

My supervisor was keen to stress that I was unlikely to make any major, enlightening discovery as we mapped the next four years of my life ( well three, I believe the last year will mainly be spent writing up- if I get any results!). But given that I am investigating an area that is largely unknown ( the metabolic response of host plants when infected with Orobanche or Striga), it will be like leaping into the dark. I will be using a technique called MALDI- MS to measure the profile of metabolites ( the end products of the biochemical reactions that occur in living cells) in the infected host plant. My main task is to compare the profiles of susceptible and resistant host cultivars to see if there are any metabolites associated with resistance ( that could POTENTIALLY be exploited into novel control strategies!). Before I can get any data though, I must first optimise the plants for the MALDI technique ( see paragraph below, 'MALDI in a nutshell') as it hasn't been used for these systems before. And this is where science becomes more like cookery, or craftsmanship; tinkering about with protocols, adjusting conditions, tweaking parameters until the process finally works. I spent a very frustrating summer trying to sequence a gene; the problem was that the reaction ( Poly,erase Chain Reaction DNA amplification) was incredibly sensitive and would only work if the conditions were absolutely right, even a single degree difference in temperature could stop it from working! So I am nervous about how long it will take to get this technique to work. When it DOES though, it will apparently spew out so much data that I will only be able to analyse it using the special computers in the department. So I envisage long, lonely nights, after everyone else has gone home, staring at the screen in a darkened room, trying to make sense of it all....
But first I have to get to that stage!
Meanwhile I have been doing more reading for the literature review. If anything, it has made me aware of how many things I don't know. Such as basic plant families....might be useful for general knowledge crosswords too. And sunflowers....the only thing I knew about these before was that my brother managed to grow the tallest one at school. Today I learnt that there are different kinds for making either oil or confectionary. As always in science, one question leads to another.
I have also been trying to do more other things: I attended my first departmental seminar last week on how plants have been key agents in driving global climate changes in the past by David Beerling ( for more information see his book 'The Emerald Planet'). Unlike many of the seminars I attended as an undergraduate, this one was PACKED and I was lucky to get a space to crouch on the floor! I also went to a 'Women in Science and Engineering' careers event. It was heartening to hear from women who had advanced up the ranks of powerful industrial companies, such as Rolls Royce, and by far the best quote was 'I used to work at Microsoft but it wasn't challenging enough...'

MALDI- MS in a nutshell
In mass spectrometry (MS), samples are vaporised and enter a chamber in which they undergo ionisation to form charged particles ( ions). In "positive ion mode", the sample components are bombarded with a stream of electrons which knocks off negative electrons from the sample atoms, forming positive ions. These are then attracted to a source of negative charge and accelerated, so that they each have the same kinetic energy. They are then deflected by a magnetic field, to an extent which depends on their mass; lighter ions are deflected more than heavier ones. This separates the ions by their mass/ charge ratio, producing a 'profile' of charged particles, allowing the components of the sample to be identified. In MALDI (Matrix Assisted Laser Desorption Ionisation), ionisation is achieved using a UV laser. The sample is first coated in a matrix which absorbs the energy from the laser. This energy is transferred to the sample, releasing ions from the surface which are then separated in the mass spectrometer. 

Images: 
1. My bench in lab C45

2.The wonderful collection of fridge magnets in the lab



 

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