Over 100 photosynthesis researchers from around the world met in Brisbane in early July to participate in the inaugural Translational Photosynthesis Conference: Innovations in Agriculture for Food Security.

The conference covered a wide spectrum of the approaches being used around the world to develop photosynthesis-based traits that breeders can use to drive up rates of yield gains.

The conference was sponsored by GRDC and convened by the ARC Centre of Excellence for Translational Photosynthesis.

Centre director, Professor Robert Furbank, from the Australian National University (ANU), says the conference was organised to reflect the scale of the challenge across the breadth of the research, development and delivery pipeline that puts better performing varieties into the hands of growers.

"What we saw at the conference is that scientists are not working in isolated silos but are networking to create synergies that help to accelerate progress," Professor Furbank says.

"It's that integrated approach that is making it possible to target - for the first time - plant photosynthesis traits across grains, legumes and oilseeds."

Speakers representing industry, regulators, research funders and decision-makers also attended, with GRDC's genetic technologies officer, Hugo Alonso-Cantabrana, saying that GRDC has long recognised that photosynthesis has immense potential and important implications to crop productivity:

"With this conference, we saw that we have come a long way towards that goal."

Climate matters

The topic of crop resilience was a key theme, particularly in the face of the potentially devastating effects of climate change on Australian agriculture.

Professor Mark Howden, director of the Climate Change Institute at the ANU and vice chair of the UN's Intergovernmental Panel on Climate Change, gave an alarming account of the latest predictions on climate impacts on agriculture at the regional scale worldwide.

Notably, he reported that Australia will likely deal with more extreme droughts, heatwaves and spring frost events, while some competitors in parts of the northern hemisphere are predicted to actually benefit from increased rainfall and milder conditions.

Even under the less extreme modelled scenarios, it is likely that an area the size of India will be removed from global agricultural production by the end of the century due to climate change.

Professor Furbank says that there is a clear need for 'climate change adapted germplasm' coupled with high-tech agronomy to achieve a more resilient agriculture.

Resilience is key

With drought and heat impacts front of mind, a number of speakers directly addressed traits that improve crop resilience, including water-use efficiency.

• Rob Sharwood, from the ANU, described the biochemical basis for heat tolerance of photosynthesis and how wild relatives of cotton might contribute genes to heat-proof cotton varieties for future heatwave conditions.
• Danni Way, from Canada, described how trees cope with the challenges of climate change.
• Tracy Lawson, an International Wheat Yield Partnership (IWYP) funded researcher from Essex UK, explored the response of stomatal pores to light in wheat leaves in a canopy.

"It appears that crops may not be optimised in how they match water loss through stomatal pores across the day and balance this with carbon gain in photosynthesis," Professor Furbank says.

"There is room to select for better performance and even engineer this response."

Tony Condon, from CSIRO, explored pre-breeding strategies for this transpiration efficiency trait in wheat, while Karin Chenu, from the University of Queensland (UQ), demonstrated how to integrate crop modelling, physiology and genetics to improve water-use efficiency in wheat.

Also from UQ and the Centre of Excellence, Alex Wu, described how he integrated a leaf-level model of photosynthesis into the APSIM crop growth model.

This advance makes it possible to preview the likely yield impacts associated with photosynthesis traits across Australia's major growing environments.

AI - the good news

While there are clearly major challenges ahead for Australian farmers, there were also good news stories from the conference speakers.

Professor Furbank's talk explored the development of new plant phenomics technology based on using light to interrogate plant physiology.

When linked to machine learning and artificial intelligence (AI), these new spectral (or light-based) technologies are helping to identify genetic variation in the efficiency of photosynthesis. With GRDC and IWYP investment, this is an area that is advancing rapidly.

Additionally, Onno Muller, from Juelich Germany, and Pablo Zarko-Tajeda, from the University of Melbourne, discussed the latest scalable sensor technologies that can be used to capture spectral data in the paddock.

Opportunities exist for growers to also benefit from this technology by providing information on crop performance.

Robotics whizz Salah Sukkarieh, from the University of Sydney, even provided a glimpse of the future with advanced sensor and AI technology allowing robots to carry out high-precision weeding and spraying, estimating crop yields and even picking crops.

The contingency plan

What do we do if the 'best of the best' germplasm still isn't good enough? More radical solutions are then needed and conference speakers discussed options: synthetic biology, gene editing and GM technology.

"We can introduce an entirely new biochemical pathway into a grain crop, make a 'programmable plant' to switch this pathway on and off, even turn a wheat crop into an oil crop at the flick of a switch by the farmer," Professor Furbank explains.

Synthetic biologists spoke of 'rewiring' plants, engineering 'gene switches' and assembling a collection of new 'genetic parts' reminiscent of upgrading a tractor.

Emma Wallington, from the UK's National Institute of Agricultural Botany (NIAB), talked about the UK's huge investment in providing a national facility for crop genetic transformation and gene editing, including generating a "parts bin" of genetic components for these engineering efforts.

This has been done in spite of EU antipathy to GM crops and was based on the realisation that all these biotechnologies are needed to meet the challenge of producing next-generation crops.

Additional applications discussed included making oil in the leaves of crops or generating crops that can fix atmospheric nitrogen to reduce fertiliser use.

Summary

The conference's broad scope better refined what agriculture needs to look like in the next 10 to 20 years to be sustainable, profitable and resilient to climate change.

Professor Furbank says that for Australia, the message is clear: "We need the best possible germplasm, along with digital agronomy and technologies that put control of their business back in the hands of farmers and not in a the lottery of a climate gamble."

GRDC's Dr Alonso-Cantabrana adds that, overall, researchers are making progress, although there is a certain anxiety to "translate" findings and deliver tangible innovation to breeders and ultimately growers.

"It needs to be noted, however, that translating photosynthesis into a viable target for genetic gain is a complex endeavour," he says."Strong foundations need to be laid first. That is to be expected. And that is what we are witnessing."

More information: robert.furbank@anu.edu.au; Hugo.Alonso-Cantabrana@grdc.com.au