“This discovery turns half a century of plant biology on its head,” said Robert J. Henry, one of the paper’s authors and professor of innovation in agriculture at the University of Queensland and director of the Queensland Alliance for Agriculture and Food Innovation.
The new discovery has the potential to lead to the development of faster growing, more drought-tolerant and heat-tolerant wheat that may be better adapted to climate change, he said.
“Wheat covers more of the earth than any other crop, so the ramifications of this discovery could be huge,” Henry said. He said it may be possible to cultivate the improved wheat in geographical areas where the grain currently cannot be grown.
The new information about wheat photosynthesis built on research from the 1960s showing that sugarcane and some other plants growing in tropical conditions had a different path to photosynthesis than about 85% of plants.
The classic pathway of photosynthesis was known as C3, while the alternative chemistry became known as C4, with C4 plants capturing carbon faster and growing at a higher growth rate than C3 plants.
“Our research characterized a previously unknown photosynthetic C4 pathway in the seeds of wheat, which is not a C4 plant,” Henry said. “This has never been known before.”
He said researchers eventually discovered wheat has a number of C4 genes on different chromosomes.
“Wheat’s photosynthetic pathway evolved 100 million years ago when atmospheric carbon dioxide levels were up to 10 times higher than they are today,” he said. “One theory is that as carbon dioxide began to decline, the plant’s sees evolved a C4 pathway to capture more sunlight to convert energy.”The study is available here.