Abstract
Root-knot nematodes (RKNs) are highly specialized parasites that interact with their host plants using a range of strategies. The esophageal glands are the main places where nematodes synthesize effector proteins, which play central roles in successful invasion. The Meloidogyne incognita effector MiISE5 is exclusively expressed within the subventral esophageal cells and is upregulated during early parasitic stages. In this study, we show that MiISE5 can be secreted to barley cells through infectious hyphae of Magnaporthe oryzae. Transgenic Arabidopsis plants expressing MiISE5 became significantly more susceptible to M. incognita. Inversely, the tobacco rattle virus (TRV)-mediated silence of MiISE5 decreased nematode parasitism. Moreover, transient expression of MiISE5 suppressed cell death caused by Burkholderia glumae in Nicotiana benthamiana. Based on transcriptome analysis of MiISE5 transgenic sample and the wild-type (WT) sample, we obtained 261 DEGs, and the results of GO and KEGG enrichment analysis indicate that MiISE5 can interfere with various metabolic and signaling pathways, especially the JA signaling pathway, to facilitate nematode parasitism. Results from the present study suggest that MiISE5 plays an important role during the early stages of parasitism and provides evidence to decipher the molecular mechanisms underlying the manipulation of host immune defense responses by M. incognita.
Highlights
Root-knot nematodes (RKNs, Meloidogyne spp.) are sedentary endoparasites of more than 3000 species of plants that cause major crop losses on a worldwide scale[1,2,3]
An esophageal gland secreting effector SPRYSEC-19 from Globodera rostochiensis has been shown to interact with the LRR region of SW5-F without eliciting a hypersensitive response (HR), supporting the idea that SPRYSECs could hijack the cellular machinery of the host to modify their target[21]
Homologues of MiISE5-like proteins from seven plant-parasitic nematodes (PPNs) species were obtained through a blastp analysis; all 475 homologues contained at least one zf_C2H2 domain, but among them, only 29 proteins contained a signal peptide and had no transmembrane domain (Tables S2, S3)
Summary
Root-knot nematodes (RKNs, Meloidogyne spp.) are sedentary endoparasites of more than 3000 species of plants that cause major crop losses on a worldwide scale[1,2,3]. Secretions synthesized by esophageal glands play a central role in nematode-plant interactions such as invasion of roots, suppression of host immune defenses, and initiation and maintenance of permanent feeding structures[6,7,8]. High throughput next-generation sequencing techniques are being applied to elucidate the mechanism of the interaction between nematodes and their host plants These techniques will lead to a much wider range of PPNs effectors being identified in the coming years. Overexpression of MiISE5 in Arabidopsis disturbed the host hormone signaling pathways involving jasmonic acid, salicylic acid, auxin and ABA These lines of evidence suggest that MiISE5 plays an important role in nematode parasitism
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
