In Progress
New Biosynthetic Pathway
The discovery of new metabolic intermediates brings scientists one step closer to figuring out how plants make chlorophyll b, a pigment important for photosynthesis and plant production.
University of Illinois plant physiologist Constantin Rebeiz, postdoctoral fellow Vinay Shedbalkar, and graduate student Ioannis Ioannides have discovered new tetrapyrroles which appear to be intermediates in chlorophyll b formation.
"This is like finding a key that will allow the whole process to unfold. Now, we can investigate the biochemistry of the various reactions responsible for chlorophyll b formation in nature," Rebeiz said. "The implications are fundamental at this stage; it is a discovery that others will build upon."
Scientists identified chlorophyll b in the 1940s. Although they have developed hypotheses to explain how plants produce the pigment, the process remains a mystery. About eight years ago, Rebeiz, Shedbalkar, and Ioannides became intrigued enough to begin working on the problem at the U of I Laboratory of Plant Pigment Biochemistry and Photobiology.
Rebeiz said the chlorophyll b biosynthetic pathway appears to be highly complex and may take several years to research. Papers on the progress of this ongoing research are being prepared for journal publication.
Researcher Honored for Contribution to Agriculture
Research aimed at boosting the capacity of a crop plant to make its own food for growth and development earned University of Illinois plant physiologist William Ogren the 1990 Alexander von Humboldt Foundation Award. Each year, a U.S. scientist who has made the most significant contribution to agriculture in America over the past five years is selected for the award, which carries a $10,000 stipend.
The award recognized the recent progress Ogren's research team has made in the laboratory. With a goal of changing plant genes to make photosynthesis more efficient, they have identified key enzymes, genes, and proteins and developed techniques for isolating, cloning, and modifying these genes. Future work will focus on transferring altered genes.
Ogren holds joint appointments in the U of I Agronomy and Plant Biology departments and is research leader of the U.S. Department of Agriculture's Agricultural Research Service Photosynthesis Research Unit.
Destruction of Cancer Cells
For innovative research, two disciplines may be better than one. Building upon their own independent research in cell metabolism, University of Illinois plant physiologist Constantin A. Rebeiz, animal scientist Keith Kelley, and animal sciences graduate student Natalie Rebeiz, have combined skills to develop a treatment that causes cells to destroy themselves.
They are using drugs and light to induce cancer cells to self-destruct. If successful, the experimental process could replace surgery now used to treat some tumors.
Although it is a novel conceptual approach to tumor treatment, manipulating cell metabolism is not new in cell biology, according to Kelley.
"We know how to kill a cell in many different ways. But, rather than injecting a chemical that kills cells, we have developed ways of modulating, destructively, cell metabolism," he said. "It opens a variety of choices and alternatives not presently available for phototherapy of cancer cells."
So far, the team has focused on interfering with metabolism of rapidly multiplying cancer cells in laboratory cultures. The next step will be to develop a model for testing the new approach on solid tumors.
"We know it works in the test tube. Now, we need to move to solid breast tumors, and if we are lucky, we may be able to inject a tumor with a solution of chemicals and a few hours later, treat it with a laser beam - no surgery - and achieve destruction of some tumor cells," Rebeiz said.