How Fixing a Glitch in Photosynthesis Can Feed the World
The solution for the food crisis has never been more urgent.
With the human population growing much faster than the rate of food being grown, the food crisis has never been more evident. In fact, the United Nations’ Food and Agriculture Organisation estimates that production will need to almost double in order to meet that demand — and so far, no one is entirely clear on how to do that.
Ever since the first crop was domesticated in 9300 BCE, humans have created several methods to address food problems. In fact, today’s crop practices are dominated by fertilisers, pesticides, and GMOs.
Recently, plant biologists at the University of California have begun heading a new front of “getting more bang for their agricultural buck.” Their research returned to the beginning of it all: photosynthesis. Although it’s the very foundation of all life on Earth, photosynthesis is surprisingly inefficient. Indeed, many crops only use about 1% to 2% of the light that hits a leaf. In order to address this drawback, scientists looked into the plant’s “sun-shield” mechanism called nonphotochemical quenching (NPQ).
NPQ is the plant’s natural defence against excessively bright sunlight by converting photons into harmless heat. And like someone who forgets to doff their sunglasses indoors, this botanical sun shield takes hours to turn off when a shadow passes over a leaf. In 2004, Stephen Long and colleagues from the University of Illinois in Urbana calculated that NPQ can reduce the amount of carbon dioxide turned into sugars by up to 30%. The result: sloppy photosynthesis.
After reading Long’s paper, Krishna Niyogi of the UCLA had an idea to turn off NPQ faster. The strategy was to add extra copies of three genes whose proteins should speed the response to shade. Niyogi, Long, and their postdocs took these genes from the widely studied mustard Arabidopsis thaliana and inserted them into tobacco plants, which are quick and easy to test. The modified tobacco bulked up their leaves, stems, and roots, weighing 14% to 20% more than unmodified plants after 22 days.
Although more research is needed to see if modifications result in unaccounted consequences, this research could have potentially have a global impact.
“I have my fingers crossed that they’ll put it into a crop plant and it’ll work,” Merchant said. “And even if it doesn’t work at 15%, even if it works at 5%, that’s still pretty good, if you think about how much agriculture we’re doing, not just in the U.S. but worldwide.” — Niyogi
