Plant scientists at Lancaster University, with support from the University of Illinois, have made an important advance in understanding the natural diversity of a key plant enzyme that could help address the looming threat of global food security.

Rubisco is the central enzyme responsible for photosynthesis in plants, enabling them to absorb carbon from the atmosphere on which they depend to live and grow. Until now, the extent of natural diversity of Rubisco across plant species was relatively unknown, according to a news release from the University of Illinois at Urbana-Champaign.

In the most comprehensive study of its kind to date, the Lancaster University-led research team discovered that some of the species it looked at had more effective and high-performing Rubisco than several of the major crops species like wheat and soybeans.

As part of the study, researchers from Lancaster University and Liverpool John Moores University looked at 75 plant species, including grasses, wild rice, melons and beans from across the world, and assessed the ability of their Rubiscos to assimilate carbon dioxide at a range of different temperatures in order to replicate the effects of a changing climate.

The researchers' work was supported by RIPE (Realizing Increased Photosynthetic Efficiency), a research grant led by the Carl R. Woese Institute for Genomic Biology at the University of Illinois at Urbana-Champaign.

Publishing their results in the journal Plant Physiology, the researchers said they were excited by the range of performance of Rubiscos isolated from the different land plants.

Some of these Rubisco enzymes have superior characteristics that will offer the possibility to engineer plants that grow more quickly and have less need for additional fertilizers.

As part of the RIPE consortium, the Lancaster researchers and their collaborators are working toward improving crops, including rice, cassava, soybean and cowpea.

"The plants we examined came from a range of environments, from sub-Saharan Africa to temperate regions of Europe and Asia and northern Australia," Lancaster research associate Douglas Orr said. "We also analyzed the effect of temperature on Rubisco biochemistry in all these species to explore how different Rubiscos respond to changing temperatures, which can help us understand how the changes occurring in our climate may impact plant growth."

"These discoveries are an important advance for RIPE," added RIPE director Stephen Long, professor of plant biology and crop sciences at the University of Illinois. "They show the existence of forms of this key enzyme that, introduced into crops, would increase their productivity and efficiency of both nitrogen and water use and forms that will function well at future increased global temperatures."

Lancaster lecturer Elizabete Carmo-Silva noted, "This large data set has shed new light on the variation present in nature. We were able to identify a number of 'superior' Rubiscos, which modeling suggests could improve photosynthetic efficiency in crops such as wheat and soybeans. This provides important information in our efforts to produce more sustainable crops."

Lancaster professor Martin Parry added, "This new information gives us the opportunity to tailor the photosynthetic performance of crops for specific environments."

The study, "Surveying Rubisco Diversity & Temperature Response to Improve Crop Photosynthetic Efficiency," is available online at http://dx.doi.org/10.1104/pp.16.00750.

RIPE is funded by the Bill & Melinda Gates Foundation. The Lancaster Environment Centre RIPE team is led by Parry, and the overall RIPE project is led by Long, who recently also joined Lancaster University.