research.gif (2985 bytes) Dr. Gary Coté, Professor of Biology

[ Coté Home | Teaching | Publications | Professional | Personal]


Crystal Idioblasts
Plant cells that create microscopic crystals


Currently my research interests focus on plant cells that produce crystals of calcium oxalate.  I am particularly interested in plants of the Arum family, and do most of my work on the common -- and poisonous -- houseplant, Dieffenbachia (right).  This plant, and some of its aroid relatives has crystals that can be actively shot out of the cell, presumably into the mouth tissues of anything eating it.  A picture of one of these ballistic cells is shown below.  Note the nipples at either end where the cell wall is weak and can  be ruptured to allow crystals to be shot out.  This cell is called a biforine.  
  Dieffenbachia and its fellow aroids also contain many other kinds of cells that make crystals (called crystal idioblasts --"idioblast" means "different cell").  A few other kinds of crystal idioblasts are shown below.  The flower-like ones are druses and the other is a bundle of raphides.  Why do plants make these crystals?  The most popular theory is that they make them to discourage animals from eating them, but maybe they provide structural support or a place to store calcium.  Why do plants make so many kinds of crystals? Right now, nobody knows.
In my lab we use bright-field, fluorescent, and polarization microscopy to study crystal idioblasts.  The pictures at right were taken with polarization microscopy, which is particularly useful for studying crystals. Below is shown a biforine photographed under polarization microscopy.    
  We have worked out methods for isolating live idioblasts from leaves so that we can study these peculiar cells (below, Jeremy Hensley and Raymond Hein are preparing a large batch of idioblast cells).  We are using the tools of biochemistry to study these cells and how they are different from other plant cells.

We are also studying crystal idioblasts in the flowers of Dieffenbachia's aroid relatives.  Although crystals have been thoroughly documented in the leaves of hundreds of species, relatively little is known about crystals in the flowers.


Are you a student interested in research on crystal idioblasts?  Come talk to me.

Every student in biology should become involved in true scientific research at some point in their education.


Check out the projects we have accomplished or are working on:

Isolation of live crystal idioblasts
Living crystal idioblasts in culture
Effect of herbivory and hormones on crystal idioblasts
All the crystal idioblasts in Dieffenbachia
Development of crystal idioblasts in Dieffenbachia leaves
 The proteome of Dieffenbachia crystal idioblasts
The transcriptome of Dieffenbachia crystal idioblasts
Crystal idioblasts in flowers of other aroids
Chemistry of the crystals

You may also check out the students who have worked with me and the projects they performed.  Go to my  Research Advisees page.