Two of the most harmful diseases that plague rice across the world are caused by bacteria. The first disease, bacterial blight, can reduce yield by 50%, and the other, though not as damaging as bacterial blight, can cause bacterial leaf streak. However, bacterial leaf streak is becoming more prominent and increasingly harmful.

The two bacteria involved in blight and leaf streak, Xanthomonas oryzae pathovar oryzae and its close relative Xanthomonas oryzae pathovar oryzicola, respectively, enter rice plants and take control of certain cellular processes. The two bacteria differ in their locations within the rice plants, however. Pathovar oryzae attacks the vascular system of the plant, resulting in a quicker spread of the disease than its cousin, oryzicola, which grows in the tissue between veins.

Researchers are trying to understand which plant genes aid in immunity towards the two bacteria. In order to determine genes responsible, the researchers are exposing resistant rice varieties to each bacterium, then checking what genes are activated and to what extent. By deducing which genes help immunity, the genes can be bred into the DNA of susceptible plants. If successful, this research could help save rice farms immense amounts of money, and in turn result in cheaper prices for the billions of consumers around the world.

Discussion Question: Do you think that gene expression could vary in the transgenic plants containing new immunity genes? How would this affect the transgenic plants’ ability to fight off bacterial infection?

News Article: http://www.sciencedaily.com/releases/2009/04/090401164047.htm
Journal Article : http://www.biomedcentral.com/1471-2180/8/99