Title : Transcriptome analysis of resistant and susceptible sweetpotato cultivars infected with root-knot nematode Meloidogyne incognita.
Abstract:
Nematodes are one of the major limiting factors in sweetpotao production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to field grown sweetpotato. As of today, no studies have been published on global gene expression profiling in sweetpotato infected with RKN or any other plant parasitic nematode. Therefore, in the present study, we performed root transcriptome analysis of resistant (cv. Juhwangmi) and susceptible (cv. Yulmi) sweetpotato cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 407,106,902 pair-end reads were generated on an Illumina Hi-Seq 2000 platform and assembled into 148,666 transcripts from the fibrous roots of both cultivars. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological process. Candidate genes that contribute to protection against M. incognita in sweetpotato were proposed, and sweetpotato-nematode interactions with respect to pathogenesis-related 10 gene and trypsin inhibitor-mediated defense signaling are studied.
