Sowing seeds for more abundant rice crops

How ingenuity will feed the world.

Genetic engineering and ecologically responsible growing practices needn’t be strange bedfellows, says plant geneticist Pamela Ronald.

Plant geneticist Pamela Ronald is widely known for her work that makes it easier to grow rice, one of the world’s most important staple foods. The role that genes play in a plant’s response to the environment is the focus of Ronald’s research as a professor in the Department of Plant Pathology and the Genome Center at the University of California at Davis.

But genetic engineering alone won’t be enough to meet worldwide food demand, Ronald believes. With her husband, organic farmer Raoul Adamchak, she argues that the world needs many other tools to feed its growing population–including organic agriculture, innovative farming systems, and government policies that support ecologically responsible food production.

Pamela Ronald
Photo: Debbie Aldridge, University of California, Davis

“You can’t generalize about an approach or a seed that will solve all of our problems,” she says.

Ronald recently talked with FutureFood 2050 about how to best address some of the world’s coming food needs, and the role of women scientists in that effort.

FutureFood 2050: How have you used genetic engineering to help rice farmers and consumers in developing countries?

Ronald: Our laboratory has isolated and characterized the Xa21 gene, which confers resistance to a common rice pathogen. We also have identified a gene called Sub1 that helps rice plants resist flooding, which ruins 4 million tons of rice every year in Bangladesh and India. My collaborators at the International Rice Research Institute introduced the Sub1 gene into varieties that are favored by farmers in India, Bangladesh and other flood-prone countries. As farmers in that region have adopted the new rice varieties carrying the Sub1 flood-tolerant gene, they have been able to produce more rice because Sub1 rice produces threefold to fourfold more grain compared to conventional varieties when flooded. Last year 4 million farmers grew this type of rice.

Our research is very important for farmers in less-developed countries, such as eastern India and Bangladesh. Many of them live on less than $1 per day, and in Bangladesh two-thirds of daily calories come from rice. So it’s very important for families to achieve good yields.

And in changing climates, [scientists predict] an increase in floods. Flood-resistant rice varieties are very important for farmers in this area of the world. Farmers in India and Bangladesh have told our team that when they plant rice strains with the flooding resistance gene, their [annual] yields are large enough that the farmers can feed their families and sell extra rice to earn income.

FutureFood 2050: Many critics of genetically modified foods oppose commercializing Golden Rice [rice genetically enriched to produce provitamin A], which was developed to address widespread vitamin A deficiency in developing countries. Why do you think Sub1 rice has not become a similar target?

Ronald: Sub1 rice was developed by marker-assisted breeding, which is not a target for activists. About 50 years ago scientists identified a very unusual rice plant that could withstand two weeks of flooding. My collaborators and I isolated that gene, and it has been introduced into several varieties that farmers in Asia raise.

FutureFood 2050: What do you see as the best ways to support more sustainable agriculture efforts?

Ronald: From an agricultural and scientific point of view, it’s clear that we need to use every tool to enhance sustainable agriculture. We need to enhance local food security and reduce environmental impacts, such as overuse of expensive and toxic inputs [pesticides and fertilizers]. We need to grow more food using less land and less water, and we want to be sure that farmers can afford to grow food and consumers can afford to buy it. These are the goals of sustainable agriculture for the future.

FutureFood 2050: Is there any way that organic agriculture and genetic engineering strategies can work together?

Ronald: Many important ideas from organic agriculture are being applied to conventional farms, including integrated pest management, crop diversity and crop rotation. Organic farmers aren’t allowed to use genetically engineered crops now, so they don’t have access to some modern technologies, and I think that will limit our ability to expand organic farming. But the other 99 percent of agriculture does have access to new seed varieties, and we can see that using modern seed varieties with ecologically based farming techniques will be the most powerful approach.

In a way, the organic vs. genetic engineering debate is a false fight. They both have the same goal, which is ecologically based agriculture. Organic agriculture has been an important advocate for more sustainable practices, but it also has limitations. There are pests and diseases that organic farming practices can’t control.

In a way, the organic vs. genetic engineering debate is a false fight. They both have the same goal, which is ecologically based agriculture.”
— Pamela Ronald

One example occurred in Hawaii, where the ringspot virus wiped out the entire papaya crop on Oahu in the 1950s. Farmers moved the industry to the island of Hawaii, but the virus also started infecting plants there, and there was no organic or conventional method for controlling it. What has worked for the past 20-odd years is a genetic engineering approach that takes a trace amount of the virus and expresses it directly into the plants, something like immunization. That strategy has saved the papaya industry. We need to consider what technology is appropriate for particular crops at particular locations.

FutureFood 2050: Does your work with rice have the potential to help farmers solve problems with other crops they grow?

Ronald: We have been collaborating with Leena Tripathi, a plant biologist at the International Institute of Tropical Agriculture in Kenya, on a very serious pathogen called banana Xanthomonas wilt, which is devastating banana plantations in eastern Africa. There is no good method for controlling it. Farmers can clip buds from banana plants to try to avoid infection, but once the plants are infected, they have to destroy their fields and start again.

This pathogen is very similar to the one we study in rice, and we have hypothesized that the Xa21 rice resistance gene might be able to function in other plant species. My collaborators in Kenya have engineered bananas to carry the Xa21 receptor, and found that the engineered plants were very resistant to the banana pathogen in greenhouse tests. If those results can be replicated in field trials, it could be very useful for farmers.

FutureFood 2050: How has being female affected your work, for better or for worse?

Ronald: I’ve been very lucky. I have worked with very supportive men and women throughout my career. But some of my colleagues have had exceptionally difficult times because they were women, including several cases of sexual harassment. There’s no doubt that there are many more challenges for women. You look around rooms, and often you’re the only woman. Sometimes you don’t notice it, and sometimes you feel uncomfortable but don’t know why until you look back and realize that you were the only woman there.

FutureFood 2050: Do you think there will be more opportunities for women food scientists in the future?

Ronald: When I was young, most of the speakers at meetings were men, but that is changing. I think science is more interesting, exciting and fun when women are involved. Men and women have similar approaches to science, and we’re trained in the same way, so I don’t think you can make any generalizations about how women do science. But there certainly are cultural issues. If you don’t have very many women in science, it’s hard to recruit others because people tend to recruit others who are a lot like them–usually unconsciously.

Achieving a 50/50 ratio of women and men as professors should solve many problems because it won’t seem like such a challenge for young women to succeed in science. They will have more role models and more people to talk to. We need to do a lot of work on recruiting men and women equally.

Jennifer Weeks

Jennifer Weeks is a Massachusetts freelance journalist who specializes in environment, science and health. She has written for more than 60 newspapers, magazines and websites, including the Washington Post, Boston Globe Magazine, Popular Mechanics, Audubon, Discover and Slate.

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