Growing food in a warming climate
We all love leaves. We can drive hundreds of kilometres to see their brilliant colours as they change in autumn, compost them, jump in piles of them, seek their shade and even eat them. But why have some leaves evolved differently than others? And why does it matter?
New Corresponding Member of the Australian Academy of Science, Professor Jane Langdale, has dedicated her career to understanding the genetic mechanisms that underpin how leaves develop and evolve.
Her earlier research used diverse plant groups including mosses, lycophytes, ferns and seed plants to investigate how leaf development mechanisms changed as land plants evolved. Currently, she is exploring genetic mechanisms that affect the way leaves are constructed and have an impact on how efficiently they can carry out photosynthesis.
Plants use photosynthesis to convert carbon dioxide, water and energy from sunlight into organic compounds, or energy. Some plants can carry out this process more efficiently than others, depending on the tissue structures in their leaves and the surrounding environmental conditions.
Varied photosynthesis efficiency
The efficiency of photosynthesis depends on an enzyme called rubisco, that captures carbon dioxide from the atmosphere and converts it into simple sugars through a process called carbon fixation. However, sometimes rubisco can latch onto oxygen molecules instead. This kickstarts a process called photorespiration—a different reaction that uses up time and energy without fixing carbon dioxide. Plants using this older and simpler (but less efficient) form of photosynthesis are called C3 plants and include valuable crops such as oats and rice.
Plants known as C4 plants get around the wasteful process of photorespiration by using a different enzyme to initially capture carbon dioxide, converting it into a four-carbon molecule (hence C4) which is then transported to specialised leaf structures in which rubisco is compartmentalised. These specialised leaf structures grow in a ring shape, almost looking like a paw print, completely surrounding and shielding rubsico from the outside world.
C4 plants thrive in hot, dry climates—think pineapple and sugarcane. Researching their traits is becoming increasingly important as our planet warms. Other plants, meanwhile, are less efficient in hot regions. That’s a problem when we’re growing some of the most valuable agricultural crops in hotter regions. With a better understanding of how C4 leaf structures develop, scientists could incorporate some of that sweet C4 efficiency into traditional C3 plants, substantially boosting crop yields in the process.
That’s where Langdale’s research comes into play. She studies how those ring-like structures, called ‘Kranz anatomy’, develop in C4 plants. She hopes that if we can introduce C4 traits into major crops such as rice and wheat, it could help us produce food more efficiently.
A global vision
Much of Langdale’s work is being carried out in the context of the multinational C4 rice project that aims to introduce C4 traits into rice crops. The project, involving an international group of researchers, aims to sustainably boost yields by creating rice that uses that highly efficient C4 photosynthesis process. It is predicted to increase photosynthetic efficiency by 50 per cent, while also improving nitrogen and water use efficiency. Researchers hope this will provide insight into new ways to sustainably feed the global population, which Langdale thinks is one of the biggest scientific challenges the world faces.
“Science should never be a single-nation endeavour,'' she says. “Interactions and collaboration between people from different cultures, with a broad range of views and experiences, are essential for the synergy that fuels truly original and creative scientific advances.”
Langdale didn’t always focus on plants, nor did she plan for a career in science. “I did what felt right at each junction,” she says. “But underlying that apparent randomness was a need to problem-solve and work through things logically.”
After graduating from the University of Bath in the UK in 1982, she went on to do a PhD in human genetics at the University of London and postdoctoral research at Yale University, where she switched focus to the molecular and genetic basis of plants.
Langdale is most proud of the people she has worked with over the years. “Any recognition of myself or my research is recognition of the wonderful people that have contributed to the discoveries that we have made,” she says. “From the technicians who wash the lab glassware to the postdocs who challenge my ideas and prove me wrong.”
Langdale is currently a Professorial Fellow at The Queen’s College, Oxford. She was elected a Member of the European Molecular Biology Organisation in 2007, a Fellow of the Royal Society in 2015 and an International Member of the US National Academy of Sciences in 2019. In 2018 she was appointed Commander of the Most Excellent Order of the British Empire (CBE) for services to plant sciences.
“I have family, friends and many colleagues in Australia, and to be recognised by the Australian Academy of Science is an incredible honour,” she says. “I hope that I am able to contribute to the Academy’s mission in a meaningful way.”