Evaluation of dsRNA delivery methods for targeting macrophage migration inhibitory factor MIF in RNAi-based aphid control

Shaoshuai Liu, Maria Jose Ladera-Carmona, Minna Poranen, Aart J.E. van Bel, Karl-Heinz Kogel, Jafargholi Imani

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Macrophage migration inhibitory factors (MIFs) are multifunctional proteins regulating major processes in mammals, including activation of innate immune responses. In invertebrates, MIF proteins participate in the modulation of host immune responses when secreted by parasitic organisms, such as aphids. In this study, we assessed the possibility to use MIF genes as targets for RNA interference (RNAi)-based control of the grain aphid Sitobion avenae (Sa) on barley (Hordeum vulgare). When nymphs were fed on artificial diet containing double-stranded (ds)RNAs (SaMIF-dsRNAs) that target sequences of the three MIF genes SaMIF1, SaMIF2 and SaMIF3, they showed higher mortality rates and these rates correlated with reduced MIF transcript levels as compared to the aphids feeding on artificial diet containing a control dsRNA (GFP-dsRNA). Comparison of different feeding strategies showed that nymphs' survival was not altered when they fed from barley seedlings sprayed with naked SaMIF-dsRNAs, suggesting they did not effectively take up dsRNA from the sieve tubes of these plants. Furthermore, aphids' survival was also not affected when the nymphs fed on leaves supplied with dsRNA via basal cut ends of barley leaves. Consistent with this finding, the use of sieve tube-specific YFP-labeled Arabidopsis reporter lines confirmed that fluorescent 21 nt dsRNA(Cy3), when supplied via petioles or spraying, co-localized with xylem structures, but not with phloem tissue. Our results suggest that MIF genes are a potential target for insect control and also imply that application of naked dsRNA to plants for aphid control is inefficient. More efforts should be put into the development of effective dsRNA formulations.

Original languageEnglish
JournalJournal of plant diseases and protection : scientific journal of the German Phytomedical Society (DPG)
Number of pages12
ISSN1861-3829
DOIs
Publication statusE-pub ahead of print - 3 May 2021
MoE publication typeA1 Journal article-refereed

Fields of Science

  • Macrophage migration inhibitory factor (MIF)
  • Phloem
  • Sitobion avenae
  • Xylem
  • dsRNA
  • 11831 Plant biology

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