Submitted to: DNA Based Markers in Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 2, 1997
Publication Date: N/A
Interpretive Summary: The soybean cyst nematode (SCN) is a major pest of soybean and is a devastating pest of soybean worldwide. Infection of the soybean plant by SCN results in poor root growth, yellowing of leaves, and inhibition of shoot growth. Strategies for reducing the damage of SCN include using SCN-resistant soybean cultivars, combined with crop rotation using non-susceptible crops. However, there are numerous races of SCN and control of damage can be difficult. We are studying the molecular events occurring in resistant and susceptible soybean cultivars upon invasion by SCN. We are identifying genes that are induced upon inoculation of resistant soybean cultivars, but not induced in susceptible soybean cultivars with SCN. We cloned and DNA sequenced portions of 35 genes that are present in the resistant inoculated plant but not in the susceptible, uninoculated or wounded controls. The DNA sequences corresponding to these genes were compared against nucleotide and protein sequence databases to determine if we could identify their function. Some of these genes are involved in regulation of gene expression while others are genes involved in a general response to disease and stress. This study is important to scientists working on novel ways to make soybean more resistant to nematodes.
Technical Abstract: The soybean cyst nematode (SCN), Heterodera glycines Ichinohe is a major pest of the soybean worldwide and is responsible for millions of dollars worth of damage in the USA. There are numerous races of SCN and control of damage can be difficult. We studied the differential expression of genes that are induced upon inoculation of resistant and susceptible soybean cultivars with soybean cyst nematode, race 3. Thirty combinations ofprimers were used to generate differential display bands from the different plant tissue samples. We cloned and sequenced 35 bands that are present in the resistant inoculated plant but not in the susceptible, uninoculated or wounded controls. According to the timing of gene expression, these cDNAs can be assigned to early (6-24 hours), intermediate (24-48 hours) or late (48-144 hours) stages of the nematode infection process. Genes that are induced include those involved in regulation of gene expression such as transcription factors and different nucleotide binding proteins, and general defense response genes such as chitinases and peroxidases is detected. The study of differential gene expression throughout the nematode infection process is of importance to plant scientists who are designing ways to make soybeans more resistant to SCN.