The Fate of Phosphorus
Wolf Scheible, Ph.D., is researching a problem that most people don't know exists. Scheible, the Noble Research Institute's newest principal investigator, comes to the organization from Germany's esteemed Max Planck Society. He brings almost 20 years of research to bear in his exploration of how plants efficiently use nutrients, especially phosphorus.
Most of the world's population gives little thought to phosphorus, much less how plants use it, but every living organism depends on this chemical element. Phosphates (natural compounds that include phosphorus) are a building block of life, present in DNA and RNA. They are also a key to production in agriculture.
Phosphorus-enriched fertilizer promotes abundant, healthy, high yielding plants. It is a linchpin for growing food, and the world is running out of readily accessible rock phosphate, the main source of phosphorus fertilizers.
"The majority of the world is just now becoming aware of this serious problem," Scheible said.
In the 1960s, the Green Revolution spread modern agricultural practices around the world and dramatically increased the demand for phosphorus-based fertilizers. With the global population set to increase from 7.0 to 9.1 billion in the next 20 years, the demand for food and plant biomass for energy production will drastically increase as will the need for phosphorus.
The Global Phosphorus Research Institute estimates that mining can only provide enough phosphorus to meet the increasing demand for 30 to 40 years. "You cannot substitute something for phosphorus, and you can't grow food without it," Scheible said. "We have to think hard about how we are going to use our resources. My research looks at how we can get the plant to better use phosphorus and other nutrients. If they use them more efficiently, then we will use less fertilizer and the world's supply will last longer."
Equations and Tanks
Scheible's research - as with his journey to the Noble Research Institute - builds on a lifetime engrossed in science. For Scheible, science and mathematics are seemingly encoded into his genetic makeup. His family tree boasts a litany of professionals in both fields. His father was a math professor. His grandfather, uncle and mother were architects. Of his three siblings, two are mechanical engineers.
As a child, Scheible spent hours engrossed, not in fairy tales, but in a math book, contemplating riddles most children would only see on a test. Math eventually gave way to chemistry. He built rockets using potassium nitrate and tissue paper. "I never burned anything down," he said with a sly smile. "But I could have very easily."
By 16, Scheible honed in on food science and became engaged in biochemistry, which manifested itself as a desire to become a medical doctor.
However, Germany's conscription required him to enlist in the military for 15 months during the mid-1980s. He traded solving equations for driving tanks. The time serving his country proved invaluable and redirected his interests.
During his stint in the military, Scheible became interested in physiological biochemistry. By 1986, he had completed his service and was studying his new passion at the University of Bayreuth where he earned a diploma (a five-year degree that is like combined bachelor and master's degrees in the United States).
At Bayreuth, he also met his future doctoral mentor, a young professor named Mark Stitt. "He inspired in many ways," Scheible said. "Maybe it was his long, curly hair or John Lennon glasses, but he was passionate and brilliant."
Scheible and Stitt formed a lasting collaboration. When Scheible graduated in 1992, he spent six months at Versailles in France preparing for his doctoral work, then, late in the year, he followed Stitt to the University of Heidelberg to research nitrate signaling and nitrate reduction. They discovered that the nitrate ion itself, not a product of its metabolism, is a key signal that regulates gene expression, nitrogen assimilation and carbon metabolism in plants.
"This was a significant breakthrough," Scheible said. "Signals within plants continue to play a role in my research."
Scheible graduated in 1996 and served as a postdoctoral fellow from 1997 to 2000 at the Carnegie Institute for Plant Science at Stanford University under the guidance of Chris Somerville, Ph.D. During his postdoctoral stint, he studied cell wall biosynthesis - an important process for the production of biofuels from plants. Under Somerville, he identified two of the first plant cellulose synthases that are required for biomass production.
At the same time, Stitt had become Director of the Max Planck Institute of Molecular Plant Physiology (MPI-MPP). Soon, Scheible's mentor came calling and made him a group leader in 2001. At the MPI-MPP, Scheible focused on nutrient use efficiency in plants. He would spend a decade becoming one of the world's foremost experts on the subject.
The Ardmore Connection
Scheible's time at the MPI-MPP afforded him the opportunity to form collaborations with many of plant science's leading researchers, including Michael Udvardi, Ph.D., a former MPI-MPP group leader, who came to the Noble Research Institute in 2006.
When Scheible began looking at the next phase of his career, he saw an opening at the Noble Research Institute and reached out to his friend and collaborator. "It was an exciting possibility to add a researcher of Wolf's caliber to an already excellent group of scientists," Udvardi said.
Rick Dixon, D.Phil., director of the Noble Research Institute's Plant Biology Division, echoed Udvardi's sentiment. "Dr. Scheible is a phenomenal researcher. He brings a wealth of experience and insight to the Noble Research Institute," he said. "Scheible, Udvardi and several other principal investigators will collaborate on projects aimed at plant productivity and sustainability."
For Scheible, the chance to come to the Ardmore, Okla.,-based organization was equally important. "The Noble Research Institute offers researchers so many advantages - tremendous facilities, unparalleled support and two other divisions that can help move research from the laboratory to the field."
Scheible will begin at the Noble Research Institute in January 2012. His goals are to advance the technology to investigate plant genomics, while focusing on nutrient use efficiency in plants and specifically the looming phosphorus crisis.
No More Lazy Plants
In the simplest of terms, Scheible said crops are lazy in their use of nutrients. They take in only a fraction of the nutrients agricultural producers provide, letting the rest go to waste. The remaining fertilizer is used by microbes or runs off and negatively impacts the environment. "We put a lot of fertilizer on the field and plants take up too little," Scheible explained. "My research ultimately will help develop plants that use phosphorus more efficiently and reduce fertilizer use."
To achieve this, Scheible must define the relationship between plants and nutrients like nitrogen and phosphorus. Much like responding to drought and disease stresses, a plant will respond to nutrient stresses. When a plant requires more nutrients, it signals its roots to grow and seek more intake. When it is stressed for carbon, it puts out more leaves for photosynthesis.
"These signals are central to understanding a plant's stress responses," Scheible said. "The signals originate in the shoots and then go up or down the plant. These signals are important for understanding and correcting nutrient limitations."
Scheible will also examine how wild species manage phosphorus efficiency. Researchers have uncovered areas in southwest Australia and South Africa where the soils contain few nutrients, but the plants are thriving.
"We want to know what they are doing to survive," he said. "Then we want to transfer that ability to crop plants or develop that nutrient uptake system in crops. Efficient plants will be vital to keeping production agriculture going and feeding the world while using fewer inputs."