In 2012, Jason White, a toxicologist at the Center for Sustainable Nanotechnology in New Haven, Conn., made a discovery that overturned the thinking about plants’ circulatory systems. He was studying the way copper nanoparticles, which have antimicrobial properties and are used in a range of agriculture and health settings, could work their way into the food system, where they might pose a health risk. After spraying the leaves of corn plants with the nanoparticles, he observed that many of them ended up in their roots. “A plant physiologist explained to me how that wasn’t physically possible,” he says. “Everyone had been sure plants can only move substances up from roots to leaves, not the other way around.”
White is applying his discovery to improve plants’ ability to take in nutrients that are critical to resisting disease. A typical crop is under attack by an average of about 50 pathogens at any given time, he notes. A lack of essential nutrients such as copper, silica and phosphorus frequently makes them more vulnerable, especially at the roots. The conventional solution is to dump those nutrients into the soil, but it’s ineffective: as little as 10 percent make it into the plant. Using what he calls nano-agriculture, White’s group can deliver these nutrients to the roots by spraying the leaves.
White’s discovery is only one of a plethora of technological advances being made in agriculture. Many experts believe that this progress may change the world as profoundly as the ‘green revolution’ of the 1960s, which brought vast increases in productivity and supported a burgeoning global population.
Today's advances raise the hope of food security for the rest of the century. That would be no mean feat. The United Nations’ Food and Agriculture Organization estimates that farmers must increase food production by 60 percent by 2050 to avoid catastrophic famines and malnutrition. And they must do so even as climate change ravages crops, and new arable acreage becomes ever harder to find. “We’ll have 9 billion people on the planet by 2050,” says White. “If there aren’t big changes in how we grow food, we won’t come close to being able to feed them.”
Edit out the problems
While White is focused on creating optimal conditions for growth, others are looking at optimizing the plants themselves. CRISPR-cas9 gene editing technology is being embraced by many areas of science – including agriculture. CRISPR uses bacterial DNA as a guide to target and snip out specific bits of an organism’s genome. If researchers can identify specific genes in a plant that are inhibiting its development or threatening its life, they can use CRISPR to eliminate them or at least limit their effects. What’s more, the process doesn’t involve the controversial technique of transplanting genes from other plants.
Nigel Taylor, a senior research scientist at the Donald Danforth Plant Science Center in St. Louis, is disabling genes in cassava that makes this staple shrub susceptible to the ‘brown streak’ virus that’s long plagued farmers in East Africa. Other researchers are using CRISPR to create gluten-free wheat or peanuts that don’t trigger allergic reactions. “We just couldn’t have done this five years ago,” says Taylor.
CRISPR can also modify plants to make them easier to grow and harvest. Taylor is developing a new version of teff. The popular grass-like Ethiopian crop is susceptible to damage from high winds, making it difficult to harvest. Taylor’s group has created a semi-dwarf version that’s much sturdier. And since this new strain doesn’t use as much energy growing tall, it produces larger quantities of edible grain.
Adding in health benefits
Scientists are also tweaking genes to make plants more nutritious. Monika Garg, a plant scientist with the National Agri-Food Biotechnology Institute in Punjab, India, is adapting ancient varieties of wheat to produce complex grains, which are slower to convert to glucose in the bloodstream when consumed. That makes them healthier for people with diabetes or who are vulnerable to developing it. “The diabetic population here [in India] is increasing at an alarming rate,” says Garg. “There’s a large consumption of rice and wheat, which have a high glycemic index.”
Garg has focused on crop varieties that seem to slow the progress of diabetes. Enlisting both conventional cross-breeding techniques and CRISPR gene editing, her group has developed wheat, maize and millet that provide nutrients often lacking in diets in India, including dietary fiber and amylose, a glycemic-index-lowering form of starch. These ‘double biofortified’ plants can then be further improved with higher levels of zinc and iodine for extra health benefits. “Now we’re working on enhancing the yield of these crops, because farmers won’t accept them if they don’t have the same high yield as their normal crops,” says Garg.
The technology can in time be applied to other crops and other countries – including to help mitigate some of the challenges of climate change. “In 30 years, it’s going to be too hot to grow corn in the U.S. midwest,” says Taylor. “Farmers are going to have to adapt and figure out what they’re going to grow instead.” In other words, the next green revolution might take place much closer to home.
Read more about technological advances in agriculture and other fields on Mega.online. Mega seeks to energise and enrich the debate over how to create a better functioning economy and society with articles and videos featuring leading academics, scientists and entrepreneurs active in the fields of sustainability, technology, health, alternative energy and agriculture.
