Q&A with Prof. Peter Waterhouse

March, 2010

Waterhouse Group

Prof. Peter Waterhouse joined the School in 2008 as an ARC Federation Fellow, coming from CSIRO Plant Industry in Canberra. His group occupies newly-built office and laboratory space on Level 8 that features a specialised glasshouse for growing the plants that form the cornerstone of his work. Peter's highly regarded research focuses on the mechanisms by which plants resist viral invasion and one of his major contributions to date lies in his discovery of a mechanism for RNA-mediated gene regulation in plants - what has become known as RNA interference or RNAi. Peter was recently awarded the Prime Minister's Science prize for this work.

Do you remember when the idea first crystallized that you would become an academic?

I did my PhD at a Research Institute in Scotland and loved it – the country, the people and the research. But the question was: could I keep doing research (and get paid) or did I have to do what my mum suggested and ‘get a real job’? By a complete stroke of luck, I received a fabulous job offer from CSIRO in Australia. I was just recently married and we decided it would be a great adventure to go to the other side of the world for 3 years before returning home and facing the unwelcome prospect of getting a ‘real job’. That was in 1982!

Who do you think has been your most influential mentor(s) during your scientific career?

There have been a few, like Sir Greg Winter and Prof. Bob Symons, but the biggest influence would definitely be from Jim Peacock, who was the chief scientist at CSIRO Plant Industry for more than 20 of the years that I was there. His management style (with me at least) was to first make me defend my science in very robust debates and then, if satisfied, he would give rock-solid encouragement and support. It was quite a surprise when I first met him. Here I was coming from a Research Institute where students were expected to be very respectful and call everyone Doctor or Professor, and anyone over the age of 30 wore a suit and tie. But when I was first taken to meet “The Chief” (I’d had visions of meeting up with Sitting Bull), there he was sitting in his office in shorts and sandals, with his socks pulled up to his knees, saying: call me Jim.

What discovery, related to your research, would you most want to be awarded the Nobel Prize for?

Actually, a number of people have told me that I was nominated for the Nobel Prize for our discovery on how to silence genes in plants - so it would have been nice to have won it for that! Unfortunately for us, a couple of American scientists were awarded the prize for describing in animals what we were finding in plants... they beat us to the punch by just a few months. Nevertheless, we were awarded the Prime Ministers Prize for Science in 2007, which was a real honour.

What do you think is the most pressing and exciting question in your field?

We’re getting really interested in epigenetics. It seems probable that we (humans, animals and plants) not only inherit genes from our parents but also their state (on or off) and that this can be influenced by the environment. For example, just suppose your mum’s blood group is AA and your dad’s is OO. Genetics would say that you are AO and, because A is dominant, your blood group is A. If epigenetics somehow gets into the act, the A gene that you inherited from your mum (with an identical nucleotide sequence that was fully functional in her) might get wrapped up in proteins in a special way so that it is stopped from expressing, and so you would appear to have an OO blood group. However, if something happened to remove these repressive epigenetic marks within you, the A gene would turn on again and your blood group would change back to AO.

One idea that we find intriguing is that epigenetics can fine tune plants to a temporarily changed environment and then pass these settings to their offspring. For example, a plant that finds itself growing in drought conditions might use epigenetics to switch off the genes in some non-essential, water-expensive pathways and also pass this arrangement on to the next generation. If, as is quite likely, drought conditions prevail the following year when the next generation germinates, the seedlings would get a head-start by not having their water-expensive pathways blasting away at full throttle. Being epigenetic regulation (as opposed to inheritance of homozygous null alleles incapacitating the pathways), if the rains come, the plants can reverse these marks and indulge again in the luxury of water-hungry pathways.

The first question is “is this scenario true or just wishful thinking?” and the second is “how do the mechanisms of triggering, maintaining and resetting epigenetic marks work?” We think the scenario is very plausible and we have some knowledge of what the epigenetic marks are and how they might operate, but there is still a great deal to be discovered and understood. To me, this a fascinating area and it may have implications on how to protect our food crops for the challenges they (and we) face in adapting to climate change. However, the concept of epigenetics has a long and controversial history and has tainted the scientific careers of people like Jean-Baptiste Lamark and Paul Kammerer. Hopefully, they were simply ahead of their time and the same fates that befell them do not await today's epigeneticists!

What are the most exciting things happening in your lab at the moment?

We have a number of things cooking at the moment. Mostly they are about small RNA mediated processes in plants. In some projects, we are developing assays, using a range of pretty fluorescent coloured proteins, to in vivo image (ie make movies of) microRNA-mediated gene regulation in plants, in real time. In others, we are studying how viruses combat being attacked by small RNAs produced by their host plants. Another project is looking at the epigenetics of how a plant can tell the difference between self and non-self genes. With this, the concept is that plants are able to distinguish between transgenes (genes newly inserted into a plant genome by transposons, retroviruses or genetic engineers) and endogenes ("natural genes"). Plants tend to treat their own genes with respect but disrespect invading ‘alien’ genes, and switch them off. We are using a number of approaches including mutant screens to explore how this all works.

On a more commercial slant, we have a couple of projects, with local and multinational companies, using small RNAs to protect crops from nematodes, and another aimed at mass production of valuable therapeutic proteins using plants as biofactories.

What do you enjoy most about being in academia?

University life is still quite new to me, so it’s interesting seeing the differences (the pluses and the minuses) between here and at CSIRO. I’m enjoying the increased interaction with students and also the freedom to do what’s interesting -not solely working on projects aimed at commercial outcomes.

What would you do differently in your academic career if you had your time over?

I have no idea!

What are you most passionate about outside the laboratory?

Apart from my family, I guess I’m really enjoying my mid-life crisis by doing marathons and triathlons - my next aim is ironman.

What achievement outside science are you most proud of?

I’m almost as proud of my plastic triathlon medals as I am of my science medals! It’s a cool sport, where I get to compete alongside people with a wide range of ages and abilities, including Olympians and national champions. I find that the older I get, the fewer competitors there are in my age group, and the higher the chances of a podium finish!