Plant Imaging Study Challenges Textbook View

April 24, 2012 - News Release

A study challenging a scientific notion held since the 1880s and still published in standard biology textbooks has been authored by Jaideep Mathur, a professor in the Department of Molecular and Cellular Biology (MCB) at the University of Guelph.

Mathur’s research team, including four undergraduate students and MCB Prof. John Greenwood, found that plant cell components called plastids responsible for photosynthesis do not form networks to exchange proteins, as previously thought. The researchers used microscopic live-imaging of a fluorescent protein from a brain coral found in shallow warm-water reefs.

“Our findings contradict a view that has been presented as fact in textbooks despite a lack of critical empirical evidence,” said Mathur. “The results of our study are of a fundamental nature that could have a direct impact upon biology education. Breakthroughs such as this are infrequent in basic biology, simply because of the sheer number of scientists who have studied the phenomenon on a routine basis – in this case, for over 125 years.”

In 1888, scientists reported that plastids could link together by tentacle-like filaments called stromules. As recently as 12 years ago, research appeared to show that stromules sometimes link or fuse plastids. Experiments in 1997 demonstrated that green fluorescent protein (GFP) from jellyfish can move between connected plastids, suggesting that stromules act as conduits for large molecules to be exchanged between plastids.

Mathur’s team used a fluorescent protein called Eos to colour each plastid differently and observe their interactions clearly under the microscope.

Although stromules from different plastids appeared to contact each other, the plastids stayed the same colour, without forming networks or fusing. Mathur said keeping plastids separate might increase biochemical diversity within a cell and account for the high survival rate and versatility of plants.

The study, published in The Plant Cell, is available online.

Mathur has used imaging with fluorescent tags and computer technology for more than a decade. By colour-coding organelles, he can watch interactions among parts of single plant cells.

At the Max Planck Institute in Cologne, Mathur was among the first scientists to demonstrate the practical uses of GFP in plant research. Later at the University of Cologne, he cloned and characterized several new genes from plants. He came to U of G in 2004.

“I believe that there is a lot left to be learned; new tools lead to new discoveries,” he said.

Stromules

Contact:
Prof. Jaideep Mathur
Molecular and Cellular Biology
University of Guelph
519-824-4120, Ext. 56636
jmathur@uoguelph.ca
http://www.uoguelph.ca/~jmathur/

For media questions, contact Communications and Public Affairs: Lori Bona Hunt, 519-824-4120, Ext. 53338, or lhunt@uoguelph.ca, or Shiona Mackenzie, Ext. 56982, or shiona@uoguelph.ca.

University of Guelph
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Guelph, Ontario, N1G 2W1
Canada
519-824-4120