The crop scientist

Professor Graham Farquhar speaks about a distinguished research career that spans a range of fields and interests, from the development of models for photosynthesis and water use in plants to contemplating becoming a professional dancer and advising on global change.

Australian Life Scientist: How did you come to be an environmental biologist?

Professor Graham Farquhar: I always thought I was going to be a scientist like my father, although he was more an agricultural extension agent than a scientist.

Both my parents were born on the land. My father used go around and talk to the farmers about new scientific methods and I thought it was a fabulously important role because it linked scientists to farmers, which is a good two-way street.

Then my father went to America when I was about 13 or 14 and came back with a textbook on biophysics. He said that this field called biophysics was going to be the next great revolution, after the biochemical revolution of chemistry integrating with biology.

He talked to Professor Ralph Slatyer, who was working on plant water relations at CSIRO Land Research at the time - Ralph later became Australia’s first Chief Scientist in 1989, advising Bob Hawke.

So I followed the advice from my father, and Ralph, to do physics first and pick up the biology later. I did physics and maths at Monash for two years and then moved to Canberra and did my third year at the Australian National University (ANU). That was about the time Ralph moved from CSIRO to the Research School of Biological Sciences at ANU.

ALS: Where did you do your postgrad studies?

GF: I was going to do my honours year in Ralph Slatyer’s group but a scholarship was advertised in biophysics at the University of Queensland (UQ). I applied and got one of two scholarships and did my honours year there. That was my first introduction to plant physiology.

Then one of the PhD students at UQ told me that it would be great to do a PhD at the ANU, in Ralph Slatyer’s new Department of Environmental Biology in Canberra. So I went back in 1970.

In those days the Research School of Biological Science was a part of the well-funded Institute of Advanced Studies that was separate from the undergraduate Schools of Botany and Zoology. It had good equipment, overseas visitors and people going overseas themselves - it was quite an elite group and I was really lucky to be there.

My supervisor was Professor Ian Cowan, who had also been trained as a physicist and a mathematician, so I had this rigour in physics and maths combined with experiments. I did my PhD on stomata - the pores in leaves that effect water loss and CO₂ uptake.

The group had a great mixture of theory and experiment. I think it’s really good to have that mix and I’ve managed to keep it around me ever since.

ALS: And you pursued extracurricular activities at the same time?

GF: Yes. In my honours year I snuck into a dance performance of the Bolshoi on Tour. I really enjoyed it - maybe because it was free and because I’d nicked in, and a couple of nights later I bought tickets and persuaded a pretty girl to go with me.

When I came back to Canberra to start my PhD I became involved in ballet and helped start a group called NUDE - National University Dance Ensemble. So I led this parallel life of dance and environmental biology, and that continued for a long time.

During my PhD we held a festival, the Aquarius Festival of the Arts, and I was the organiser for the dance section. We had the Dance Company of New South Wales, which later became the Sydney Dance Company, the Australian Dance Theatre from Adelaide, Garth Welch who was premier danseur with the Australian Ballet, Keith Bain and other fantastic people. We ran it on a budget of almost nothing.

Most of the time I was doing normal classical ballet training but there were usually roles for extras when the Australian Ballet or the Australian Opera came to town - there’d be a need for someone to be a tree or something. And some of the philharmonic productions needed dancers so I was involved in lots of theatre.

ALS: How did you decide whether to become a dancer or a scientist?

GF: I went to America to do a postdoc for three years where I also danced.

The best stomata physiologist at the time I was doing my PhD was Klaus Raschke, a very interesting and amazingly resourceful man who was working at Michigan State University (MSU) in East Lansing in the US. I moved there and worked on stomata and measuring CO₂ uptake.

The research lab at Michigan was funded by the Atomic Energy Commission, originally to look at what happened to plants subjected to radiation, because nobody knew - in those days there was money available for this type of research.

During that time we made the transition to having computers that controlled the gas-exchange facility - during my PhD we’d used analog computers which don’t exist anymore. In the early part of my thesis everything was charted in ink with a pen quivering around the place and doing things with rulers in a way that people couldn’t imagine today.

There was a modern dance group on campus at MSU and I also danced with the East Lansing Ballet. At one stage I went to New York for a while and considered becoming a dancer. I did classes down there but ended up going to more parties than I should have for a serious dancer. As a dancer, I made a great scientist.

At the end of that period I went back to East Lansing. The research was terrific and it was a tremendous group of people, a very cosmopolitan international place and a very stimulating time.

ALS: Then you came back to Canberra and established yourself as a plant scientist?

GF: At the end of those three years I managed to get a job back in Canberra, once again in Slatyer’s group but this time as a Research Fellow.

I visited India and China before coming back to Canberra, this was 1976, so it was before China had opened up and that was really interesting.

I ended up doing some research with Ian Cowan again. I was happy to work with Ian, he was someone I really liked and admired.

After Ian came back from a sabbatical in Germany, we worked together on various things and then he became my champion as well as my mentor. He pushed to get a tenured position available for me and advised me that I should stop working with him so that I could have an independent career. I remember being a bit shocked by that because it seemed a bit silly to me since we enjoyed working together.

But I did some work without him and that was successful.

ALS: Can you talk about some of the high points in your research career?

GF: The work with Ian Cowan was a highlight. He and I were trying to home in on conditions that created the best ratio of carbon gain or carbon dioxide gain to water loss in plants. We thought a lot about how stomata affected both.

In my PhD thesis I had this naive idea that maybe stomata were optimising something. At the time Ian quizzed me about it because he didn’t understand what I meant but he said to leave it in for the thesis. He then thought about it a lot more deeply and realised what I meant but took it much further.

We then wrote a paper together about optimisation of stomatal behaviour. That’s a paper I really love.

To do that we needed to know what the transpiration rate would be if stomatal conductance was a little bit different from what it actually is. We could calculate that from the physics, so that wasn’t so hard. But to calculate what the photosynthetic rate would be if the stomata were just a little bit more open or a little bit more closed was much more demanding.

When stomata open and close, the CO₂ concentration inside the leaf changes. If they are closed a little bit there is less evaporation, which means the leaf heats up a bit. So you have both CO₂ and temperature effects on photosynthesis that you need to understand.

This directly led me to thinking about a model of photosynthesis, and it was another highlight for me.

In those days photosynthesis was divided up into different camps and each camp was convinced, in some ways correctly, that theirs was the rate-limiting step in photosynthesis. People who worked on stomata were confident theirs was the limiting step, people who worked on rubisco - the first carboxylating enzyme in the capture of CO₂ - thought theirs was the most limiting step, people who worked on the Calvin cycle and regeneration of the acceptor which reacts with CO₂ thought theirs was, and so on.

There had been some attempts to create more integrated models and I started trying to improve on those.

Dr Joe Berry, who was visiting from the Carnegie Lab in Stanford, was very clever about thinking how these different steps might limit and we ended up working on that together. He wrote a conference paper on it and I followed that up with a more detailed paper that also involved a PhD student from the time, Susanne von Caemmerer. That paper has been very successful - a number of other papers have been derived from it and it’s been cited two or three thousand times.

ALS: Is this what led to you looking at global climate change?

GF: The work I had been doing on the stomata opening or closing and changing the concentration of CO₂ inside the leaf meant that we started doing work on responsiveness to CO₂. As well as modelling, we also did experiments and I thought a lot about how plants responded to CO₂. Then that started becoming an issue with the rise of atmospheric carbon dioxide levels.

The increase in atmospheric CO₂ was talked about by very few people back then - in the early 1980s. The Earth Summit in Rio [where the international treaty, the United Nations Framework Convention on Climate Change, was signed] was in 1992 and Kyoto wasn’t until 1997.

We’d already been involved with it in the context of the environmental effects on photosynthesis, particularly effects of CO₂. So when grants became available for things to do with global change, I checked out the definition of climate change and it included CO₂ concentration and the effects of CO₂ itself.

Although in Australia, and probably everywhere else, the money was given to meteorologists.

ALS: You were invited to Kyoto as a science adviser, what was that like?

GF: That was a real adventure. I was invited at the very last minute and went along to negotiations about the protocol as a science adviser.

John Howard was Prime Minister at the time and was not going to go to Kyoto because he recognised that Australia was a big polluter.

I worked with Jon Lloyd on the National Greenhouse Gas Inventory section on land use change and forestry. This inventory was part of the international requirement to report on climate change.

We started thinking about land clearing and it turned out that it was a huge source of CO₂. I’ve always thought it was perfectly legitimate to include the effects of land clearing - it doesn’t matter whether the CO₂ comes from a burning tree or a burning car - provided the clearing is permanent and the trees don’t regrow somewhere else.

It was hard to get numbers at the time. But on the advice of a colleague we used estimates based on the sale of herbicides and how much was needed per hectare, because at the time certain herbicides were used to kill trees and clear the land.

In the negotiations that went on preceding Kyoto, 1990 was decided as the base year for emissions. Land clearing had been going on at a very high rate in Australia in 1990 and, for whatever reason, was slowing down. I then realised the emissions had gone down and if they included this the budgeting would look very different.

Howard, after discussion with Ralph Slatyer, then decided Australia could go to Kyoto and said he wanted scientists who knew about land clearing to attend, and they asked me to go.

We managed to get land exchange and forestry into the final protocol, which allows for credit for reducing land clearing emissions. It was on the very last night that it went through - so much has happened since then it’s probably irrelevant now, but at the time it was really exciting.

From that involvement I could see we needed much better, more precise figures in the science and that’s what led to the national greenhouse accounting system.

That work was interesting and I was keen to see it done properly but it’s sort of arbitrary how the inventory is organised - it could be done a different way - so much depends on the politics.

I’ve withdrawn from that now and am happy to have more time for real science.

ALS: Did that work lead to your involvement with the International Panel of Climate Change?

GF: Kyoto was for me specifically land exchange and forestry, and involved the IPCC’s Task Force on National Greenhouse Gas Inventories. My involvement with the Assessment Reports of the IPCC was independent of the Kyoto work.

The IPCC Assessment Reports had a broader interest in terms of the response of the biosphere to changes in CO₂ and the important question of how much the biosphere will take up as CO₂ rises or how it will respond to changes in temperature.

I was a lead author in the second IPCC assessment report and a convening lead author in the third report. I also shared the Nobel Peace Prize in 2008 with other IPCC scientists.

The inventory work and the assessments went on in parallel and there was not too much overlap between them. I was more interested in the straight scientific research, which I continued to do in parallel.

ALS: You’ve received numerous medals for your research achievements. A recent one was the 2014 Rank prize, which is regarded as the equivalent of a Nobel Prize for agriculture. Can you describe what this was for?

GF: This arose from research I first did on carbon isotopes with two American colleagues - Joe Berry and Marion O’Leary.

About 1% of carbon has an extra neutron which forms a stable carbon isotope, ¹³C. It was already known that plants have less ¹³C in them than what is in the atmosphere and the question was: what was causing this discrimination?

Many of the principles were already understood, so it was a bit like the photosynthesis work I had done where it was a matter of synthesising what was known. 

We devised a model that did that synthesis and saw that CO₂ concentration inside the leaf emerged from the calculations as being a key parameter. I knew that that related to CO₂ gain and water loss from the work that I’d done before that. And I could see that if there were genetic variations in water-use efficiency we should be able to pick it up with ¹³C isotopes; so we predicted that in the paper.

Then Richard Richards, a colleague I’d known from high school who had become an experimental plant breeder with CSIRO, and I decided to look at this experimentally. Richard had been growing some wheat varieties under different conditions and measuring water-use efficiency. Everybody expected there to be no difference or no genetic variation, but he had seen some.

We decided we would laboriously measure the carbon isotope content of that plant material, which we did, and gradually this beautiful picture emerged just like the theory had predicted. The champagne flowed and we published the paper in the Australian Journal of Plant Physiology.

That was in 1984. I received the CSIRO Research Medal in 1991 for the underlying research technique. Then later on we started screening different wheats much more broadly and Richard’s team was back-crossing the water-efficient ones into commercial lines to come up with lines that had water-use efficiency. We won a CSIRO team medal for that research in 2001.

The Rank Prize was for coming up with a technique for producing varieties of wheat that are more water sufficient. Our own view is that the technique should be used more broadly, and for other crop species and, indeed, more wheat varieties.

ALS: Is that research being applied now to improve wheat and crop production?

GF: Not as much as you would think or hope. The first wheat variety, Drysdale, was released and it seemed to go well but wheat rust is continually evolving and sure enough a rust evolved that Drysdale could not resist. That was difficult because it had been performing so well.

Then Rees was released by CSIRO, after which a commercial company made releases in 2011 and since. I think three more varieties were released that were derived from populations selected on the basis of being more water-use efficient.

Richard sends that material to developing regions where there are programs in place focusing on agriculture. We have kept the program rigorous and - I think because we had a better understanding of the deep science underneath it all - we’ve been able to be more productive than other programs that have faltered.

It’s not something that you can just turn the handle on. There are many many steps between the behaviour of an individual leaf and an individual plant at the physiological level, and, finally, crop performance.

If you close the stomata you would think there would always be some penalty in terms of growth - this is early in the season. But you would hope that the water that’s saved is sufficiently greater and available to help the crop do better at the end.

But in general, people are most interested in getting more yield for the same amount of water. In theory you could say you want the same yield and save water, but for rain-fed crops, farmers are not that interested in saving water. They would rather get every bit of water effectively going into the grain as photosynthate, and then let the soil replace the water before the next crop.

ALS: Do you think the research will have an impact on food security?

GF: Certainly we would hope so. Food security intersects with funding, economics and all sorts of things.

It’s something I have been very passionate about - improving agriculture and agricultural sustainability. It’s largely a political and economic problem - a problem of countries that don’t have stable infrastructure. You don’t get much starvation in places that have stable governments and infrastructure where seeds can be transported and harvest delivered.

We used to have terrible famines in Indonesia, India and Pakistan and so on, but the Green Revolution has been fantastic in saving humanity from those terrible scourges.

Now an incredibly huge proportion of food is wasted - grain piles are siloed or stored under the control of various national governments and a lot of food is thrown away.

My intuition is that economics and politics will continue to demand that yields go up and that means research will still be needed. I wish I could do an analysis to prove this.

Image caption: Graham Farquhar with Penny Richards in 1982 in a publicity shot for the Canberra Dance Ensemble.