Date Published: May 24, 2019
Publisher: Public Library of Science
Author(s): Wenwen Song, Nawei Qi, Chen Liang, Fangmeng Duan, Honghai Zhao, Kandasamy Ulaganathan.
Heterodera glycines (soybean cyst nematode, SCN) is one of the most devastating pathogens of soybean worldwide. The compatible and in compatible interactions between soybean and SCN have well documented. Nevertheless, the molecular mechanism of a nonhost resistant response in soybean against SCN infection remains obscure. Toward this end, a global transcriptional comparison was conducted between susceptible and resistant reactions of soybean roots infected by taking advantage of finding a new pathotype of SCN (SCNT). The soybean cultivar Lee, which exhibits resistant to SCNT and susceptible to HG 220.127.116.11.7 (SCNs) was utilized in the expriments. The results highlighted a nonhost resistant response of soybean. Transcriptome analysis indicated that the number of differentially expressed genes (DEGs) in the resistant interaction (3746) was much larger than that in the susceptible interaction (602). A great number of genes acting as intrinsic component of membrane, integral component of membrane, cell periphery and plasma membrance were remarkably enriched only in the resistant interaction, while the taurine and hypotaurine, phenylpropanoid pathway, plant-pathogen interaction and transcript factors were modulated in both interactions. This is the first study to examine genes expression patterns in a soybean genotype in response to invasion by a virulent and avirulent SCN population at the transcriptional level, which will provide insights into the complicate molecular mechanism of the nonhost resistant interaction.
Soybean (Glycine max (L.) Merr.) is an important crop that provides a valuable source of protein and oil all over the world . However, soybean production is severely challenged by Heterodera glycines (soybean cyst nematode, SCN), which is one of the most devastating pathogens of soybean roots, causing losses of approximately 1.5 billion dollars annually in USA . To date, the primary management for the control of SCN is breeding and growing resistant cultivars, which is the most economical and environment friendly solution . The sources of resistance to SCN are identified as PI 88788, Peking and PI 437654, while another genotype Lee is susceptible cultivar.
There has been increasing research mainly focusing on different soybean genotypes which displayed resistant or susceptible to the same SCN population [10–12, 16]. However, these studies were not fully able to take into account part of DEGs screened from the above studies possibly caused by different genotypes. In spite of a microarray analysis of the same soybean genotype infected by Heterodera glycines with compatible and incompatible responses, the resistant cultivar Peking was employed in this work to investigate plant defense responses . Although microarray analysis was conducted in SCN-susceptible soybean [17–19], the differences between susceptible and resistant responses in the SCN-susceptible variety remain unknown. Based on the above studies, we conducted the comparative transcriptome sequencing to examine SCN-susceptible soybean genes involved in susceptible and resistant responses to invasion of different SCN populations, which would provide an insight into soybean distinct responses to SCN populations of significantly different pathogenicity. As a result, genes related to the interaction in the soybean cultivar Lee could be screened to reveal infection mechanism of SCN. This is the first study to examine genes expression patterns in a SCN-susceptible soybean genotype in response to invasion by highly and weakly pathogenic SCN populations to describe a nonhost resistance response in soybean against nematodes at the transcriptional level using Illumina 2000 sequence technology.
This is the first report describing genes profiles of SCN-susceptible soybean involved in resistant and susceptible responses. Our study revealed specific regulations of genes involved in the nonhost resistant reactions to SCN infection at the transcriptional level in which, a number of transcripts with different accumulations exhibited distinct responses to different SCN populations. Functional confirmations of significantly regulated genes can be performed by overexpressing or silencing them in soybean. Overall, comparative transcriptome analysis provides insights into the complicate molecular mechanism of the SCN-susceptible soybean served as both good-host and nonhost interactions.