Summer 2003

Standing tall
By Susan Steeves

Agronomy researcher Dan Szymanski uses Arabidopsis in his research to identify mutations in genes that affect a plant’s cytoskeleton and cell shape. Discovering ways to change the size and shape of leaves and roots may enable scientists to grow more plants in smaller areas, as well as prevent crop damage. (Photo by Tom Campbell)

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Department of Agronomy’s Dan Szymanski says an undergraduate class on plant development eventually led him down the pathway to Arabidopsis research. “I felt that plants were understudied, and I found plant development fascinating,” says Szymanski, whose research focuses on altering plants’ structure.

The diminutive weed gives him the perfect way to discover methods to change the size and shape of leaves and roots. Understanding how cell shape is controlled and how it affects plant function and structure may enable scientists to grow more plants in smaller areas or to grow two different types of plants in the same field at the same time, he says. This could provide larger yields from smaller acreage, an important goal as farmland decreases and world population increases.

Another important way to increase yield is to prevent crop damage. “Understanding the mechanisms of plant cytoskeletal reorganization in response to pathogenic, bacterial, fungal or insect attack, or just in development, is very limited,” Szymanski says.”

Researchers use known Arabidopsis gene mutations that cause a plant to behave differently than would the wild type, or normal plant. Assessing mutated plants helps pinpoint the normal gene’s function and the workings of various biological processes. Researchers then can insert an altered gene, protein or other molecule into plants to produce a desired trait, such as stronger stalks to withstand wind or a larger root to These are intractable problems unless you have a genetic entry into the problem. That’s why we use Arabidopsis; we can identify mutations in genes that specifically affect the cytoskeleton and cell shape.

Plant pathologist Zhixiang Chen also investigates ways to prevent damage to plants by microbial pathogens. He’s attempting to determine why some plants are resistant to various pathogens while others are susceptible.

“Resistant plants somehow can rapidly activate a defense response upon infection by a pathogen,” says Chen. “That defense mechanism contains the pathogen to a very small area of the infected plant. On the other hand, susceptible plants cannot sense the pathogen, or defense mechanism activation is slow.”

Chen studies a gene group called WRKY, which is involved in the early step of gene expression called “transcription.” He believes these genes are involved in plants’ disease resistance response. “When we manipulate this gene, either by enhancing or suppressing it, we actually see the plant’s disease resistance change,” Chen says. Results of his studies could lead to enhanced plant resistance to bacteria, fungi and viruses.

 
 
© 2003 Purdue University College of Agriculture