Researchers are learning the secrets of the harmful cyst nematode.
Many soybean growers are all too familiar with the menacing Heterodera glycines cyst nematode, which feeds on their crop, resulting in up to $1 billion in crop loss in the U.S. each year. Recent research, funded by USDA’s Cooperative State Research, Education, and Extension Service (CSREES), is uncovering the mechanisms used by this nematode to weaken the plant’s defense system.
Recent work by scientists at the University of Missouri (UM) and Iowa State University (ISU) looked at the relationship of the juvenile cyst nematode and its host plant. As it feeds, the nematode injects secretions that modify the root cells, creating specialized feeding cells called syncytia, which provide nutrients to the nematode necessary for growth and development, as well as maintain the host-parasite relationship. In essence, the plant cell is reprogrammed by these secretions to support the feeding nematode rather than support and benefit the plant.
The researchers examined 35,611 soybean genes and obtained the first comprehensive gene expression profile of the developing syncytium during very early stages of the plant-nematode interaction. Their work shows that within two days after syncytium formation over 1,765 soybean genes changed expression.
This team found that genes for proteins involved in plant cell wall formation are compromised by interplay between plant hormones, called phytohormones. In addition, a decrease in the production of jasmonic acid may suppress the plant defense response, which allows the nematode to survive and thrive.
These findings may provide scientists the key to decipher which genes play essential roles in the induction, formation, and function of the syncytium for the survival and growth of cyst nematodes. Future work in this area may lead to new management techniques through the use of biotechnology to better control these important agricultural pests.