National Institute of Environmental Health Sciences

New Plant Research Discoveries May Help Solve Global Food Deficiencies

May 2013

By: Carol Kelly

Abstract

With the global population predicted to grow by two billion people in the next four decades, increased nutritious and sustainable food production is essential for human and environmental health. New plant research is offering potential solutions for meeting agricultural demand.

An international group of scientists led by Julian Schroeder, Ph.D., Ph.D., professor of biology and an NIEHS grantee at the University of California, San Diego (UCSD), has collectively discovered important properties about the ways plants grow and upload nutrients that could beneficially affect global agriculture.

The discoveries, recently published in a review in Nature, center on the transport proteins within plant cell membranes. Transport processes are crucial and enable plants to survive environmental stresses. With improved transporters, plants can better resist toxic metals and pests, increase salt and drought tolerance, control water loss, and expand energy storage. Together, the implications for increasing the supply of food includes enhanced staple crop yields, increased nutrient content, and improved tolerance to unfavorable soil conditions, which could mean farming on previously unusable or marginally useable land.

“More fundamental knowledge and basic discovery research is needed, and would enable us to fully exploit these advances and pursue new promising avenues of plant improvement in light of food and energy demands and the need for sustainable yield gains,” said Schroeder.

One of Schroeder’s research advances led to the discovery of a sodium transporter, named HKT1, that plays a key role in protecting plants from soil salinity stress, a key cause of major crop losses. In field trials using durum wheat plants, a staple commercial grain crop, a team of Australian scientists found that a particularly active member of the HKT1 transporter family removed excess sodium and boosted yields by 25 percent.  

Plants are the major point of entry for essential nutrients into the food chain. The work of Schroeder’s collaborator Mary Lou Guerinot , Ph.D., the Ronald and Deborah Harris Professor of the Sciences at Dartmouth College and a NIEHS grantee, contributes to understanding how plants absorb and distribute metals, such as iron. Her work is laying the foundation for crops, particularly rice, that have higher micronutrient levels and offer sustainable solutions for malnutrition.

To further address the world’s food requirements, Schroeder is also co-director of the Center for Food & Fuel for the 21st Century at UCSD. This recently established research center brings together scientists, policy makers, and industry representatives to discuss advances and stimulate collaborations across traditional boundaries. Their work concerns the use of photosynthetic organisms for enhanced food production and energy independence. The goal is to apply basic research on plants to support sustainable food and biofuel production.

“Many recent plant discoveries around the world have previously been under the radar—known only to a small group of plant biologists,” said Schroeder. “By disseminating these findings widely, we hope to educate policy makers and speed the eventual application of recent discoveries to global agriculture.”

Citation:

• Using membrane transporters to improve crops for sustainable food production. Schroeder JI, Delhaize E, Frommer WB, Guerinot ML, Harrison MJ, Herrera-Estrella L, Horie T, Kochian LV, Munns R, Nishizawa NK, Tsay YF, Sanders D. 2013. Nature 497:60-66. [Abstract Using membrane transporters to improve crops for sustainable food production. Schroeder JI, Delhaize E, Frommer WB, Guerinot ML, Harrison MJ, Herrera-Estrella L, Horie T, Kochian LV, Munns R, Nishizawa NK, Tsay YF, Sanders D. 2013. Nature 497:60-66.]

Treatment and Refill Kiosks Provide Communities with Cleaner Drinking Water

By: Megan Avakian

A new study by a team at Yale University has shown that consumption of water from community-scale water treatment and refill kiosks decreased the risk of diarrhea in an urban slum in Jakarta, Indonesia. Diarrhea is the second leading cause of death among young children. “People assume that you need very low-tech and cheap solutions for low-income people, but we saw a reduction in diarrhea rates for people living in very low-income areas in Southeast Asia that were using these novel technologies,” says lead author Laura Sima, Ph.D. “This solution is about one-fourth the price of bottled water in Jakarta and is showing similar reductions in diarrhea risk for the population of children we monitored.”

Most people living in developing countries do not have access to safe piped drinking water and cannot afford expensive bottled water. Purchasing water from community-scale water treatment and refill kiosks may provide a safe, affordable alternative to more expensive water sources. These decentralized water sources use novel membrane technologies to filter water, which is then decontaminated using either an ultraviolet disinfection or reverse osmosis purification process.  

Sima and colleagues monitored water source and diarrhea rate for 1,000 children ages 1 to 4 years in Jakarta, every day for five months. They found diarrhea incidence in an urban slum varied significantly by water source and was more than two fold higher for children consuming tap water compared to children consuming bottled water or refill kiosk water as their primary water source. The study, supported in part by NIEHS, was an interdisciplinary effort between the Department of Chemical and Environmental Engineering and the School of Public Health at Yale University, and is among the first to examine the impact of community-level water treatment and refill kiosks on health outcomes.

These findings may have promising implications for developing countries because current interventions to reduce diarrhea rates have not seen considerable success. Even when water is initially treated with a residual disinfectant, recontamination is a major concern. People living in developing countries commonly transport and store drinking water in open receptacles and use their hands or a ladle to scoop the water, practices that can re-introduce bacteria into water after disinfection. Other potential interventions, such as household-treatment of water with chlorine, have had very low adoption rates in Southeast Asia due to a cultural aversion to the smell and taste of chlorine.

“Community-scale water treatment and refill kiosks use membrane and purification technologies to remove and inactivate pathogens without leaving any taste of a residual chemical,” says Sima, who posits that the use of capped bottles at refill stations reduces recontamination because people transport and pour water from a clean, closed container rather than using a potentially contaminated tool to scoop the water.

As a postdoctoral fellow with the Environmental Health Sciences Department at Johns Hopkins University, Sima is now studying how switching water sources affects diarrhea risk. Because of widespread financial instability in low-income countries people cannot always purchase clean water, and they commonly switch water sources. “When working with low-income people you have to be aware that their financial stream may not be consistent and they might have different water purchasing habits throughout the month. We are trying to understand the correlation between how people are switching water and their diarrhea risk,” says Sima.

Citation:

• Relationship between use of water from community-scale water treatment refill kiosks and childhood diarrhea in Jakarta. Sima LC, Desai MM, McCarty KM, Elimelech M. Am J Trop Med Hyg 2012; 87:979-984. doi:10.4269/ajtmh.2012.12-0224 [Abstract Relationship between use of water from community-scale water treatment refill kiosks and childhood diarrhea in Jakarta. Sima LC, Desai MM, McCarty KM, Elimelech M. Am J Trop Med Hyg 2012; 87:979-984. doi:10.4269/ajtmh.2012.12-0224]