Surviving the next population boom with resistant crops and biofuels

UC San Diego professor Julian Schroeder’s research focuses on mechanisms in plants that help them adapt to environmental stresses such as climate change, pollution and droughts.

UC San Diego professor Julian Schroeder’s research focuses on mechanisms in plants that help them adapt to environmental stresses such as climate change, pollution and droughts.

(Photo by Erik Jepsen)

Over the next 35 years, the earth’s population is expected to grow from 7 billion to 9.5 billion. One crucial question we must answer is: How can we feed all of those people, as well as supply fuel to power our world?

During the Baby Boom era there was a similar population explosion. To deal with it, we revved up agricultural production with synthetic fertilizers and pesticides, as well as massive irrigation. We also burned fossil fuels without regard for the consequences.

Today, in the face of climate change, pollution and droughts, those very approaches have become a large part of the problem. Finding solutions is the goal of UC San Diego’s Center for Food and Fuel for the 21st Century (FF21).

“One of the biggest challenges we have now is to produce substantial yields in a sustainable way,” said Julian Schroeder, professor of biology at UC San Diego and co-director, with molecular biology professor Stephen Mayfield, of FF21. “If we can grow plants that are more resistant to stresses, we can improve their yields to feed the growing world population, and, secondly, this could free up land to grow next-generation energy crops.”


A closer look at the crop itself

Schroeder’s research focuses on mechanisms in plants that help them adapt to environmental stresses such as droughts and increased carbon dioxide in the atmosphere.

He has already made strides toward solving a problem that costs California over a billion dollars a year — excess salt in the soil caused by irrigation. The river water we use to irrigate farmland flowed over rocks, where it picked up salt. When the water evaporates in the fields, salt builds up and damages crops.

Now, thanks to Schroeder’s discovery of a sodium transporter in plants, scientists have begun breeding salt-resistant crops. One of the most successful trials was performed by a research team in Australia, where wheat yields were increased by an impressive 25%.


Schroeder’s lab also collaborated on a 2009 study led by plant cell biology professor Sean Cutler at UC Riverside. They found the receptors for a plant hormone that signals the need to retain water — an important key to breeding drought-resistant plants.

Another focus of Schroeder’s research is the effect on plants of increased levels of carbon dioxide in the air.

“We now have 40% higher CO2 in the atmosphere than before industrialization,” he said, “and it’s continuing to grow massively because of human fossil fuel burning.”

Plants need CO2 to grow, and their stomata, or pores, open and draw it in from the air. As CO2 levels in the air rise, the stomata close. This not only reduces CO2 intake but it also causes the plants to retain water. In researching this phenomenon, Schroeder discovered sensing mechanisms that signal the pores to close, which may prove helpful in breeding plants that can survive when water is scarce.

Plants as fuels — and other raw materials

Also, because plants are potential energy sources that actually remove CO2 from the air, this research can be used to develop crops for sustainable fuels.

Most people are familiar with ethanol made from corn, but it’s not the best choice for fuel because it uses only the starch in the kernel. The rest of the plant is wasted. Schroeder points out that teams of scientists are working with more promising biofuel sources that use the whole plant, such as switchgrass and miscanthus.

While Schroeder concentrates on land-based agriculture at UC San Diego, co-director Mayfield studies algae as a source of food, fuels and other products. He’s currently involved in a project using algal oil to make polyurethane for surfboards, and the first algae-based, sustainable surfboards were produced in April.


But it takes more than science to achieve groundbreaking changes. Factors like public acceptance of new products and the realities of business all come into play.

“The problems in society now are so complex that you cannot solve them simply by an invention in the lab,” said Mayfield. “So economists, social scientists and others are all part of the center and are applying themselves to the task.”

With that much brainpower, one can’t help but be optimistic about finding solutions for an abundant and sustainable future.

Maxine Nunes, Brand Publishing Writer