Early transcriptional responses to soybean cyst nematode HG Type 0 show genetic differences among resistant and susceptible soybeans

Key message: Root transcriptome profiling of three soybean cultivars and a wild relative infected with soybean cyst nematode at migratory phase revealed differential resistance pathway responses between resistant and susceptible genotypes. Abstract: The soybean cyst nematode (SCN), Heterodera glycines, is the most serious pathogen of soybean production throughout the world. Using resistant cultivars is the primary management strategy against SCN infestation. To gain insight into the still obscure mechanisms of genetic resistance to nematodes in different soybean genotypes, RNA-Seq profiling of the roots of Glycine max cv. Peking, Fayette, Williams 82, and a wild relative (Glycine soja PI 468916) was performed during SCN infection at the migratory phase. The analysis showed statistically significant changes of expression beginning at eight hours after inoculation in genes associated with defense mechanisms and pathways, such as the phenylpropanoid biosynthesis pathway, plant innate immunity and hormone signaling. Our results indicate the importance of the early plant response to migratory phase nematodes in pathogenicity determination. The transcriptome changes occurring during early SCN infection included a number of genes and pathways specific to the different resistant genotypes. We observed the most extensive resistant transcriptome reaction in PI 468916, where the resistant response was qualitatively different from that of commonly used G. max varieties.